Dear Stockholders:

On January 12, 2021, Cantel Medical Corp., which is referred to as Cantel, and STERIS plc, Solar New US Holding Co, LLC and Crystal Merger Sub 1, LLC, which are referred to as STERIS, US Holdco and Crystal Merger Sub, respectively, entered into an Agreement and Plan of Merger, as amended on March 1, 2021, which is referred to as the Merger Agreement, providing for the acquisition of Cantel by STERIS by means of a series of mergers, which are referred to as the Mergers, as described more thoroughly in the accompanying proxy statement/prospectus, involving cash-and-stock consideration. After the transactions contemplated by the Merger Agreement are consummated, Cantel will be an indirect wholly owned subsidiary of STERIS.

Cantel stockholders, which are referred to as Cantel Stockholders, as of the close of business on    , 2021 are invited to attend a special meeting of Cantel Stockholders, which is referred to as the Special Meeting, on    , 2021, at     Eastern Time to consider and vote upon a proposal to adopt the Merger Agreement and certain other matters related to the Mergers.

If you are a Cantel Stockholder and the Mergers are completed, you will receive (unless you seek appraisal and comply with all related statutory requirements of the General Corporation Law of the State of Delaware), for each issued and outstanding share of common stock, par value $0.10 per share, of Cantel, which is referred to as Cantel Common Stock, owned by you immediately prior to consummation of the Mergers and as converted into shares of Canyon HoldCo, Inc., a Delaware corporation and direct and wholly owned subsidiary of Cantel in the Pre-Closing Merger (as defined in the accompanying proxy statement/prospectus), (i) 0.33787 ordinary shares, par value $0.001 per share, of STERIS, which is referred to as STERIS Shares, which consideration is referred to as the stock consideration, and (ii) $16.93 in cash, which is referred to as the cash consideration, and together with the stock consideration is referred to as the Merger Consideration. For a description of the Merger Consideration that Cantel Stockholders will receive upon completion of the Mergers, see the section entitled “The Mergers—Consideration to Cantel Stockholders” beginning on page 50 of the accompanying proxy statement/prospectus.

The market value of the stock consideration, but not the cash consideration, will fluctuate with the price of STERIS Shares. Based on the closing price of STERIS Shares on January 11, 2021, the last trading day before the public announcement of the signing of the Merger Agreement, the value of the Merger Consideration payable to Cantel Stockholders upon completion of the Mergers was approximately $84.66 per share of Cantel Common Stock. Cantel stockholders should obtain current stock price quotations for STERIS Shares and Cantel Common Stock. STERIS Shares are traded on the New York Stock Exchange, which is referred to as the NYSE, under the symbol “STE,” and Cantel Common Stock is traded on the NYSE under the symbol “CMD.”

The Mergers (other than the Pre-Closing Merger), taken together, and the Pre-Closing Merger, together with certain related transactions, are each intended to qualify as a “reorganization” within the meaning of Section 368(a) of the Internal Revenue Code of 1986, as amended, which is referred to as the Code, and the Mergers (other than the Pre-Closing Merger), taken together, are also intended to qualify for an exception to the general rule of Section 367(a)(1) of the Code. For a discussion of the material U.S. federal income tax consequences of the Mergers see the information included under the section entitled “Material U.S. Federal Income Tax Consequences of the Pre-Closing Merger, the Pre-Closing Conversion, the First Merger and the Second Merger” beginning on page 18 of the accompanying proxy statement/prospectus.

STERIS and Cantel cannot complete the Mergers unless, among other things, Cantel Stockholders adopt the Merger Agreement, thereby approving certain of the Mergers, at the Special Meeting.

Your vote is very important. To ensure your representation at the Special Meeting, please complete and return the enclosed proxy card or submit your proxy via the Internet or by telephone. Please vote promptly whether or not you expect to attend Special Meeting. Submitting a proxy now will not prevent you from being able to attend virtually the Special Meeting if you are otherwise eligible to vote at such meeting.

Charles M. Diker, Mark N. Diker and Diker Management LLC entered into a voting agreement with STERIS, US Holdco and Crystal Merger Sub, which is referred to as the Voting Agreement, pursuant to which they have agreed, among other things, to vote all of the shares of Cantel Common Stock beneficially owned by them (constituting approximately 10.4% of the issued and outstanding shares of Cantel Common Stock as of January 8, 2021), in favor of the adoption of the Merger Agreement, on the terms and subject to the conditions set forth in the Voting Agreement.

Cantel’s Board of Directors has (a) determined that the Merger Agreement and the other transactions contemplated thereby, including the Mergers, are fair to, and in the best interests of, Cantel and its stockholders, (b) unanimously approved and declared advisable the Merger Agreement and the transactions contemplated thereby, including the Mergers, and (c) unanimously recommends that Cantel stockholders vote “FOR” each of the proposals described in the accompanying proxy statement/prospectus.

The obligations of STERIS and Cantel to complete the Mergers are subject to the satisfaction or waiver of the conditions set forth in the Merger Agreement, a copy of which is included as Annex A-1 and Annex A-2 to the accompanying proxy statement/prospectus. The proxy statement/prospectus provides you with detailed information about the Mergers. It also contains or references information about STERIS and Cantel and certain related matters. You are encouraged to read the proxy statement/prospectus carefully and in its entirety. In particular, you should carefully read the section entitled “Risk Factors” beginning on page 31 of the accompanying proxy statement/prospectus for a discussion of risks you should consider in evaluating the Mergers and the issuance of STERIS Shares in connection with the Mergers and how such risks will affect you.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the Mergers, the adoption of the Merger Agreement, the issuance of STERIS Shares in connection with the Mergers or any other transaction described in the accompanying proxy statement/prospectus, or passed upon the adequacy or accuracy of the disclosure in this document. Any representation to the contrary is a criminal offense.

This document is dated   , 2021, and is first being mailed to stockholders of Cantel on or about   , 2021.

NOTICE IS HEREBY GIVEN that a special meeting of stockholders, which is referred to as the Special Meeting, of Cantel Medical Corp., which is referred to as Cantel, will be held on    , 2021     at     Eastern Time. In light of the public health impact of the ongoing COVID-19 pandemic and in order to protect the health and well-being of our stockholders, the Special Meeting will be held virtually via live webcast at www.virtualshareholdermeeting.com/CMD2021SM. There will be no physical in-person meeting. The Special Meeting will be held for the following purposes:

Approval of Cantel’s stockholders, who are referred to as Cantel Stockholders, for the Cantel Merger Proposal is required to complete the Mergers. Cantel Stockholders will also be asked to approve the Compensation Proposal. Cantel will transact no other business at the Special Meeting. Under Cantel’s bylaws, whether or not there is a quorum, the chairman of the Special Meeting may adjourn the Special Meeting, and may elect to do so to, among other things, solicit additional proxies if there are not sufficient votes at the time of the Special Meeting in favor of the Cantel Merger Proposal. The record date for the Special Meeting has been set as    , 2021, which is referred to as the Record Date. Only Cantel Stockholders of record as of the close of business on the Record Date are entitled to notice of, and to vote at, the Special Meeting. For additional information, see the section entitled “Special Meeting of Cantel Stockholders” beginning on page 13 of the proxy statement/prospectus accompanying this notice.

Cantel’s Board Of Directors unanimously recommends that you vote “FOR” the Cantel Merger Proposal and “FOR” the Compensation Proposal.

Each of the above-mentioned proposals are described in more detail in the accompanying proxy statement/prospectus, which you should read carefully in its entirety before you vote. A copy of the Merger Agreement is attached as Annex A-1 and Annex A-2 to the accompanying proxy statement/prospectus and a copy of the Voting Agreement is attached as Annex E to the accompanying proxy statement/prospectus.

PLEASE VOTE AS PROMPTLY AS POSSIBLE, WHETHER OR NOT YOU PLAN TO ATTEND THE SPECIAL MEETING. IF YOU LATER DESIRE TO REVOKE OR CHANGE YOUR PROXY FOR ANY REASON, YOU MAY DO SO IN THE MANNER DESCRIBED IN THE ACCOMPANYING PROXY STATEMENT/PROSPECTUS. FOR FURTHER INFORMATION CONCERNING THE PROPOSALS BEING VOTED UPON, USE OF THE PROXY AND OTHER RELATED MATTERS, YOU ARE URGED TO READ THE ACCOMPANYING PROXY STATEMENT/PROSPECTUS.

This document, which forms part of a registration statement on Form S-4 filed with the SEC by STERIS (Registration No. 333-    ), constitutes a prospectus of STERIS under Section 5 of the Securities Act with respect to the ordinary shares of STERIS, par value $0.001 per share, which are referred to as the STERIS Shares, to be ultimately issued to existing stockholders of Cantel, who are referred to as the Cantel Stockholders, pursuant to a series of mergers, which are referred to as the Mergers, as described more thoroughly in this proxy statement/prospectus, which are contemplated by the Agreement and Plan of Merger, dated as of January 12, 2021, as amended on March 1, 2021, as such agreement may be further amended from time to time, which is referred to as the Merger Agreement, among STERIS, Cantel, Solar New US Holding Co, LLC, a Delaware limited liability company and wholly owned subsidiary of STERIS, which is referred to as US Holdco, and Crystal Merger Sub 1, LLC, a Delaware limited liability company and a direct wholly owned subsidiary of US Holdco, which is referred to as Crystal Merger Sub. Each of these entities are individually referred to as a Party, and they are collectively referred to as the Parties. This document also constitutes a proxy statement of Cantel under Section 14(a) of the Securities Exchange Act of 1934, as amended, which is referred to as the Exchange Act.

STERIS has supplied all information contained or incorporated by reference herein relating to STERIS, US Holdco and Crystal Merger Sub, and Cantel has supplied all information contained or incorporated by reference herein relating to Cantel, Canyon HoldCo, Inc., a Delaware corporation and direct and wholly owned subsidiary of Cantel, which is referred to as Canyon Newco, and Grand Canyon Merger Sub, Inc., a Delaware corporation and direct and wholly owned subsidiary of Canyon Newco, which is referred to as Canyon Merger Sub. STERIS and Cantel have both contributed information relating to the Mergers contained in this proxy statement/prospectus.

STERIS and Cantel have not authorized anyone to provide you with information that is different from that contained in or incorporated by reference herein, and STERIS and Cantel take no responsibility for, and can provide no assurance as to the reliability of, any information others may give you. This proxy statement/prospectus is dated    , 2021, and you should not assume that the information contained in this proxy statement/prospectus is accurate as of any date other than such date unless otherwise specifically provided herein. Further, you should not assume that the information incorporated by reference herein is accurate as of any date other than the date of the incorporated document. Neither the mailing of this proxy statement/prospectus to Cantel Stockholders nor the issuance of STERIS Shares pursuant to the Merger Agreement will create any implication to the contrary.

Readers are cautioned not to place undue reliance on any forward-looking statements included in this communication, which speak only as of the date of this communication. STERIS and Cantel undertake no obligation to update or revise any forward-looking statement, whether as a result of new information, future developments or otherwise, except as required by applicable law. This cautionary statement is applicable to all forward-looking statements contained in this communication.

Stockholders voted together on all matters presented to Cantel Stockholders from time to time, the former Cantel Stockholders would exercise significantly less influence over STERIS after completion of the Mergers relative to their influence over Cantel prior to the completion of the Mergers, and thus would have a less significant impact on the election of the STERIS Board of Directors and on the approval or rejection of future STERIS proposals submitted to a stockholder vote.

Upon completion of the Mergers, Cantel Stockholders will no longer be stockholders of Cantel and will become shareholders of STERIS. There will be important differences between the current rights of Cantel Stockholders and the rights to which such stockholders will be entitled as shareholders of STERIS. See the section entitled “Comparison of Stockholders’ and Shareholders’ Rights” beginning on page 129 for a discussion of the different rights associated with the STERIS Shares.

If the Mergers are completed, Cantel Stockholders will cease to have any equity interest in Cantel and will not participate in its earnings or any future growth, except indirectly through ownership of STERIS Shares received as part of the Merger Consideration.

Upon completion of the Mergers, Cantel Stockholders will become holders of STERIS Shares. The businesses of STERIS differ from those of Cantel in certain respects, and, accordingly, the financial position or results of operations and/or cash flows of STERIS after completion of the Mergers, as well as the market price of STERIS Shares, may be affected by factors different from those currently affecting the financial position or results of operations and/or cash flows of Cantel. Following the completion of the Mergers, Cantel will be part of a larger company with other lines of business and a broader geographic footprint, so decisions affecting Cantel may be made in respect of the larger combined business as a whole rather than the Cantel businesses individually. For a discussion of the business of STERIS and Cantel and of some important factors to consider in connection with those businesses, see the section entitled “Information About the Companies” beginning on page 43, and the documents incorporated by reference in the section entitled “Where You Can Find More Information” beginning on page 152, including, in particular, in the sections entitled “Risk Factors” in STERIS’s Annual Report on Form 10-K for the year ended March 31, 2020 and Cantel’s Annual Report on Form 10-K for the year ended July 31, 2020.

Pursuant to the Merger Agreement, Cantel has agreed not to, among other things, (i) solicit proposals relating to certain alternative transactions, (ii) engage in discussions or negotiations or provide non-public information in connection with any proposal for an alternative transaction from a third party or (iii) approve or enter into any agreements providing for any such alternative transaction, in each case, subject to certain exceptions to permit members of the Cantel Board of Directors to comply with their duties as directors under applicable law. Notwithstanding these “no-shop” restrictions, prior to obtaining the Cantel Stockholder Approval, under specified circumstances, the Cantel Board of Directors may change its recommendation of the transaction, and Cantel may also terminate the Merger Agreement to accept a Superior Proposal upon payment of the termination fee described below.

The Merger Agreement provides that, in connection with the termination of the Merger Agreement under specified circumstances, Cantel may be required to pay to STERIS a termination fee of $127.4 million. See “The Merger Agreement—No-Solicitation” and “The Merger Agreement—Termination of the Merger Agreement” beginning on pages 85 and 91, respectively.

These provisions could discourage a potential competing acquirer that might have an interest in acquiring all or a significant part of Cantel from considering or proposing such an acquisition, even if the potential competing acquirer was prepared to pay consideration with a higher per share value than the value proposed to be received or realized in the Mergers, or might result in a potential competing acquirer proposing to pay a lower per share value than it might otherwise have proposed to pay because of the added expense of the termination fee that may become payable in certain circumstances under the Merger Agreement.

If the Merger Agreement is terminated and Cantel determines to seek another business combination, Cantel may not be able to negotiate a transaction with another party on terms comparable to, or better than, the terms of the Mergers contemplated by the Merger Agreement.

Cantel may determine to waive, in whole or in part, one or more of the conditions to its obligations to complete the Mergers. Cantel currently expects to evaluate the materiality of any waiver and its effect on Cantel Stockholders in light of the facts and circumstances at the time to determine whether any amendment of this proxy statement/prospectus or any resolicitation of proxies is required in light of such waiver. Any determination as to whether to waive any condition to the Mergers, and as to whether to resolicit stockholder approval and/or amend this proxy statement/prospectus as a result of such waiver, will be made by Cantel at the time of such waiver based on the facts and circumstances as they exist at that time.

The Merger Agreement is subject to a number of conditions that must be fulfilled in order to complete the Mergers. Those conditions include, among others: the adoption of the Merger Agreement by Cantel Stockholders, the expiration or termination of the waiting period applicable to the Mergers under the HSR Act, as well as certain other antitrust and foreign direct investment laws, the absence of certain governmental orders or laws prohibiting consummation of the Mergers, the approval to list STERIS Shares issuable in connection with the Mergers on the NYSE, the accuracy of the representations and warranties under the Merger Agreement (subject to materiality standards set forth in the Merger Agreement), STERIS’s and Cantel’s performance of their respective obligations under the Merger Agreement in all material respects, the absence of a material adverse effect for STERIS (as described in the Merger Agreement), the absence of a material adverse effect for Cantel (as described in the Merger Agreement) and Cantel’s receipt of a written opinion of Wachtell, Lipton, Rosen & Katz (or if Wachtell, Lipton, Rosen & Katz is unwilling or unable to provide such tax opinion, at the election of STERIS, from Jones Day) regarding the U.S. federal income tax treatment of the transaction. These conditions to the closing of the Mergers may not be fulfilled in a timely manner or at all, and, accordingly, the Mergers may be delayed or may not be completed.

In addition, if the Mergers are not completed by the Outside Date, which under certain circumstances may be automatically extended to January 12, 2022, and further optionally extended to April 12, 2022, in each case if required regulatory approvals have not been obtained, either STERIS or Cantel may choose not to proceed with the Mergers, and can mutually decide to terminate the Merger Agreement at any time. In addition STERIS and Cantel may elect to terminate the Merger Agreement in certain other circumstances. See the section entitled “The Merger Agreement—Termination of the Merger Agreement” beginning on page 91.

The Merger Agreement contains a number of conditions that must be satisfied or waived prior to the completion of the Mergers, including, without limitation, regulatory approvals and the approval of the acquisition by Cantel Stockholders. There can be no assurance that all of the conditions to the Mergers will be so satisfied or waived. If the conditions to the Mergers are not satisfied or waived, STERIS and Cantel will be unable to complete the Mergers and the Merger Agreement may be terminated. Furthermore, the delay in the fulfillment of such conditions could result in unanticipated expenditures of funds and other resources and/or reduce the benefits of the acquisition of Cantel, even if ultimately consummated.

If the Mergers are delayed or not completed for any reason, STERIS’s and Cantel’s respective business and financial results may be adversely affected as follows:

In addition to the above risks, if the Merger Agreement is terminated and Cantel seeks an alternative transaction, Cantel Stockholders cannot be certain that Cantel will be able to find a party willing to engage in a transaction on more attractive terms than the Mergers. If the Merger Agreement is terminated under the specified circumstances, Cantel may be required to pay to STERIS a termination fee. See the section entitled “The Merger Agreement—Termination of the Merger Agreement” beginning on page 91.

Uncertainty about the effect of the Mergers on employees and Customers may have an adverse effect on STERIS and Cantel. These uncertainties may impair STERIS’s and Cantel’s ability to attract, retain and motivate key personnel until the Mergers are completed and for a period of time thereafter, and could cause Customers and others that deal with STERIS and/or Cantel to seek to change those existing business relationships. Employee retention at Cantel may be particularly challenging during the pendency of the Mergers, as employees may experience uncertainty about their roles with STERIS following the Mergers. In addition, the Merger Agreement restricts STERIS and Cantel from entering into certain corporate transactions and taking other specified actions without the consent of the other Party, and generally requires Cantel to continue its operations in the ordinary course, until completion of the Mergers. These restrictions may prevent STERIS and Cantel from pursuing attractive business opportunities that may arise prior to the completion of the Mergers. Please see the section entitled “The Merger Agreement—Conduct of Business Pending the First Merger,” beginning on page 83, for a description of the restrictive covenants to which STERIS and Cantel are subject.

Directors and executive officers of Cantel may have interests in the Mergers that are different from, or in addition to, the interests of Cantel Stockholders generally. These interests include, among others, the treatment of outstanding equity and equity-based awards pursuant to the Merger Agreement; potential severance and other benefits upon a qualifying termination in connection with the Mergers; and rights to ongoing indemnification and insurance coverage. These interests are described in more detail in the section entitled “The Mergers—Interests of Cantel Directors and Executive Officers in the Mergers” beginning on page 74.

The Mergers may not be accretive, and may be dilutive, to STERIS’s earnings per share and cash flow from operations per share. Earnings per share and cash flow from operations per share in the future are based on preliminary estimates that may materially change. In addition, future events and conditions could decrease or delay any accretion, result in dilution or cause greater dilution than is currently expected, including:

Any dilution of, or decrease or delay of any accretion to, STERIS’s earnings per share or cash flow from operations per share could cause the price of the STERIS Shares to decline.

Each of STERIS and Cantel has incurred and will incur substantial expenses in connection with the negotiation and completion of the transaction contemplated by the Merger Agreement, including the costs and expenses of filing, printing and mailing this proxy statement/prospectus and all filing and other fees paid to the SEC in connection with the Mergers.

STERIS and Cantel expect to continue to incur a number of non-recurring costs associated with completing the Mergers, and combining the operations of the two companies and achieving desired synergies. These fees and costs have been, and will continue to be, substantial. The substantial majority of non-recurring expenses will consist of transaction costs related to the Mergers and include, among others, employee retention costs, fees paid to financial, legal and accounting advisors, fees paid to banks and other financial institutions in conjunction with obtaining financing and other related costs, severance and benefit costs and filing fees.

STERIS and Cantel will also incur transaction fees and costs related to formulating and implementing integration plans, costs to consolidate facilities and systems and employment-related costs. STERIS and Cantel will continue to assess the magnitude of these costs, and additional unanticipated costs may be incurred in the Mergers and the integration of the two companies’ businesses. Although STERIS and Cantel each expects that the elimination of duplicative costs, as well as the realization of other efficiencies related to the integration of the businesses, should allow STERIS and Cantel to offset integration-related costs over time, this net benefit may not be achieved in the near term, or at all. See the risk factor entitled “The integration of Cantel into STERIS may not be as successful as anticipated” below.

The costs described above, as well as other unanticipated costs and expenses, could have a material adverse effect on the financial condition and operating results of STERIS following the completion of the Mergers.

Many of these costs will be borne by STERIS and/or Cantel even if the Mergers are not completed.

Lawsuits arising out of the Mergers may be filed in the future. There can be no assurance that any of the defendants will be successful in the outcome of any potential future lawsuits. A preliminary injunction could delay or jeopardize the completion of the Mergers, and an adverse judgment granting permanent injunctive relief could indefinitely enjoin the completion of the Mergers.

Cantel has received an opinion from Centerview in connection with the signing of the Merger Agreement, but has not requested and obtained, and does not intend to request, an updated opinion from Centerview as of the date of this proxy statement/prospectus. Changes in the operations and prospects of STERIS or Cantel, general market and economic conditions and other factors that may be beyond the control of STERIS or Cantel, and on which Centerview’s opinion was based, may significantly alter the value of STERIS or Cantel or the prices of

STERIS Shares or of the shares of Cantel Common Stock by the time the Mergers are completed. The opinion does not speak as of the time the Mergers will be completed or as of any day other than the dates referenced in such opinion. Because Cantel does not currently anticipate asking Centerview to update its opinion, the opinion will not address the fairness of the per share Merger Consideration or aggregate Merger Consideration, as applicable, from a financial point of view at the time the Mergers are completed. The Cantel Board of Director’s recommendation that Cantel Stockholders vote “FOR” approval of the Cantel Merger Proposal and other Merger-related matters, however, is made as of the date of this proxy statement/prospectus. For a description of the opinion that Cantel received from Centerview, please see the section entitled “The Mergers—Opinion of Cantel’s Financial Advisor” beginning on page 60. A copy of the opinion of Centerview is attached as Annex B to this proxy statement/prospectus and is incorporated by reference herein in its entirety.

Completion of the Mergers may trigger change in control or other provisions in certain agreements to which Cantel is a party. If STERIS and Cantel are unable to negotiate waivers of those provisions, the counterparties may exercise their rights and remedies under the agreements, potentially terminating the agreements or seeking monetary damages. Even if STERIS and Cantel are able to negotiate waivers, the counterparties may require a fee for such waivers or seek to renegotiate the agreements on terms less favorable to Cantel.

STERIS intends to fund the cash consideration of the Merger Consideration, as well as the refinancing, prepayment, replacement, redemption, repurchase, settlement upon conversion, discharge or defeasance of certain existing indebtedness of Cantel and its subsidiaries, transaction expenses, general corporate expenses and working capital needs, through the incurrence of approximately $2.1 billion of new indebtedness. STERIS intends to incur this indebtedness through the issuance of senior notes and the entry into a new term loan agreement, although all or a portion of the expected $2.1 billion of new indebtedness may be initially obtained through a bridge loan pursuant to a bridge facility commitment previously obtained by STERIS. As of October 31, 2020, Cantel had approximately $1.0 billion of long-term indebtedness, including convertible debt, outstanding. As of December 31, 2020, STERIS had approximately $1.7 billion of long-term indebtedness outstanding. STERIS’s ability to repay these obligations will depend on, among other things, STERIS’s and Cantel’s financial position and performance, as well as prevailing market conditions and other factors beyond STERIS’s control. There can be no assurance that STERIS will be able to execute such financing transactions on favorable terms or at all.

STERIS’s increased indebtedness after completion of the Mergers could have important consequences to holders of STERIS Shares, including Cantel Stockholders immediately prior to the effective time of the First Merger who receive STERIS Shares in the First Merger, including:

The pro forma financial data and unaudited forecasted financial information contained in this proxy statement/prospectus are presented for illustrative purposes only, contain a variety of adjustments, assumptions and preliminary estimates and do not represent the actual financial position or results of operations of STERIS and Cantel prior to the Mergers or that of STERIS after completion of the Mergers for several reasons. Specifically, we have not completed the detailed valuation analyses to arrive at the final estimates of the fair values of the assets to be acquired and liabilities to be assumed and the related allocation of purchase price and the pro forma financial data does not reflect the effects of transaction-related costs and integration costs. See the sections entitled “Selected Unaudited Pro Forma Condensed Combined Financial Data” and “Comparative Historical and Unaudited Pro Forma Per Share Financial Data” beginning on pages 23 and 25, respectively. In addition, the Mergers and post-merger integration process may give rise to unexpected liabilities and costs, including costs associated with the defense and resolution of transaction-related litigation or other claims. Unexpected delays in completing the Mergers or in connection with the post-merger integration process may significantly increase the related costs and expenses incurred by STERIS. The actual financial positions and results of operations of STERIS and Cantel prior to the Mergers and that of STERIS after completion of the Mergers may be different, possibly materially, from the pro forma financial data or forecasted financial information included in this proxy statement/prospectus. In addition, the assumptions used in preparing the pro forma financial data and forecasted financial information included in this proxy statement/prospectus may not prove to be accurate and may be affected by other factors. Any significant changes in the market price of STERIS Shares may cause a significant change in the purchase price used for STERIS’s accounting purposes and pro forma financial data contained in this proxy statement/prospectus.

The Mergers involve numerous operational, strategic, financial, accounting, legal, tax and other risks; potential liabilities associated with the acquired businesses; and uncertainties related to design, operation and integration of Cantel’s internal control over financial reporting. Difficulties in integrating Cantel into STERIS may result in Cantel performing differently than expected, in operational challenges or in the failure to realize anticipated expense-related efficiencies. STERIS’s and Cantel’s existing businesses could also be negatively impacted by the Mergers. Potential difficulties that may be encountered in the integration process include, among other factors:

Following completion of the Mergers, STERIS’s success will depend, in part, on its ability to manage its expansion, which poses numerous risks and uncertainties, including the need to integrate the operations and business of Cantel into its existing business in an efficient and timely manner, to combine systems and management controls and to integrate relationships with Customers, vendors and business partners.

The success of the proposed Mergers will depend, in part, on STERIS’s ability to realize the anticipated benefits and cost savings from combining STERIS’s and Cantel’s business, including the approximately $110 million in annualized pre-tax cost synergies that STERIS expects to realize within the first four fiscal years after the completion of the Mergers. The anticipated benefits and cost savings of the Mergers may not be realized fully or at all, may take longer to realize than expected, may require more non-recurring costs and expenditures to realize than expected or could have other adverse effects that STERIS does not currently foresee. Some of the assumptions that STERIS has made such as with respect to anticipated operating synergies or the costs associated with realizing such synergies, significant long-term cash flow generation, and the continuation of STERIS’s investment grade credit profile, may not be realized. The integration process may, for each of STERIS and Cantel, result in the loss of key employees, the disruption of ongoing business or inconsistencies in standards, controls, procedures and policies. There could be potential unknown liabilities and unforeseen expenses associated with the Mergers that were not discovered in the course of performing due diligence.

STERIS and Cantel are dependent on the experience and industry knowledge of their officers and other employees to execute their business plans. Each company’s success until the Mergers and STERIS’s success after the Mergers will depend in part upon the ability of STERIS and Cantel to retain management personnel and other employees. Current and prospective employees of STERIS and Cantel may experience uncertainty about their roles within STERIS following the Mergers, which may have an adverse effect on the ability of each of STERIS and Cantel to attract or retain management and other personnel. Accordingly, no assurance can be given that STERIS will be able to attract or retain management, personnel and other employees of STERIS and Cantel have previously been able to attract or retain their own employees.

Based on the number of shares of Cantel Common Stock outstanding as of January 8, 2021 (other than Excluded Shares), STERIS expects to issue up to approximately 14,287,997 million STERIS Shares to Cantel Stockholders in the Mergers. Following their receipt of STERIS Shares as stock consideration in the Mergers, former Cantel Stockholders may seek to sell STERIS Shares delivered to them. Other STERIS Shareholders may also seek to sell STERIS Shares held by them following, or in anticipation of, completion of the Mergers. These sales (or the perception that these sales may occur), coupled with the increase in the outstanding number of STERIS Shares, may affect the market for, and the market price of, STERIS Shares in an adverse manner.

The Mergers will be accounted for as an acquisition by STERIS in accordance with accounting principles generally accepted in the U.S., which is referred to as GAAP. Under the acquisition method of accounting, the assets and liabilities of Cantel and its subsidiaries will be recorded, as of completion, at their respective fair values and added to those of STERIS. The reported financial condition and results of operations of STERIS for periods after completion of the Mergers will reflect Cantel balances and results after completion of the Mergers, but will not be restated retroactively to reflect the historical financial position or results of operations of Cantel and its subsidiaries for periods prior to the Mergers. See the section entitled “Selected Unaudited Pro Forma Condensed Combined Financial Data” beginning on page 23.

Under the acquisition method of accounting, the total purchase price will be allocated to Cantel’s tangible assets and liabilities and identifiable intangible assets based on their fair values as of the date of completion of

the Mergers. The excess of the purchase price over those fair values will be recorded as goodwill. STERIS and Cantel expect that the Mergers will result in the creation of goodwill based upon the application of the acquisition method of accounting. To the extent the value of goodwill or intangible becomes impaired, STERIS may be required to incur material non-cash charges relating to such impairment. STERIS’s operating results may be significantly impacted from both the impairment and the underlying trends in the business that triggered the impairment.

Although Cantel expects to receive a tax opinion from counsel to the effect that, on the basis of facts, representations and assumptions set forth or referred to in such opinion, the Pre-Closing Merger and the Pre-Closing Conversion, taken together, will qualify as a “reorganization” within the meaning of Section 368(a) of the Code, neither Cantel nor STERIS has applied for, or expects to obtain, a ruling from the IRS with respect to the U.S. federal income tax consequences of the Pre-Closing Merger and the Pre-Closing Conversion. No assurance can be given that the IRS will agree with the conclusions reached in such opinion or that it will not challenge the U.S. federal income tax consequences of the Pre-Closing Merger and the Pre-Closing Conversion or that any such challenge will not be sustained by a court. If the Pre-Closing Merger and the Pre-Closing Conversion, taken together, do not qualify as a reorganization for U.S. federal income tax purposes, the conversion of Cantel Common Stock into Canyon Newco Common Stock in the Pre-Closing Merger will generally be treated as a fully taxable transaction for such purposes and U.S. holders (as defined in the discussion under the section entitled “Material U.S. Federal Income Tax Consequences of the Pre-Closing Merger, the Pre-Closing Conversion, the First Merger and the Second Merger” beginning on page 18) will generally recognize gain or loss on the conversion of the shares of Cantel Common Stock into the equal number of shares of Canyon Newco Common Stock pursuant to the Pre-Closing Merger. Any such gain or loss required to be recognized by non-U.S. holders (as defined in the discussion under the section entitled “Material U.S. Federal Income Tax Consequences of the Pre-Closing Merger, the Pre-Closing Conversion, the First Merger and the Second Merger” beginning on page 18) will be subject to U.S. federal income tax only in limited circumstances.

For additional discussion of material U.S. federal income tax consequences of the Pre-Closing Merger and the Pre-Closing Conversion, see the section entitled “Material U.S. Federal Income Tax Consequences of the Pre-Closing Merger, the Pre-Closing Conversion, the First Merger and the Second Merger” beginning on page 18.

Although Cantel expects to receive a tax opinion from counsel to the effect that, on the basis of facts, representations and assumptions set forth or referred to in such opinion, the First Merger and the Second Merger, taken together, will qualify as a “reorganization” within the meaning of Section 368(a) of the Code, neither Cantel nor STERIS has applied for, or expects to obtain, a ruling from the Internal Revenue Service, which is referred to as the IRS, with respect to the U.S. federal income tax consequences of the First Merger and the Second Merger. No assurance can be given that the IRS will agree with the conclusions reached in such opinion or that it will not challenge the U.S. federal income tax consequences of the First Merger and the Second Merger or that any such challenge will not be sustained by a court. If the First Merger and the Second Merger, taken together, do not qualify as a reorganization for U.S. federal income tax purposes, the exchange will generally be treated as a fully taxable transaction for such purposes and U.S. holders (as defined in the discussion under the section entitled “Material U.S. Federal Income Tax Consequences of the Pre-Closing Merger, the Pre-Closing Conversion, the First Merger and the Second Merger” beginning on page 18) will generally recognize gain or loss on their exchange of Canyon Newco Common Stock for the Merger Consideration pursuant to the First Merger. Any such gain or loss required to be recognized by non-U.S. holders (as defined in the discussion under the section entitled “Material U.S. Federal Income Tax Consequences of the Pre-Closing Merger, the Pre-Closing Conversion, the First Merger and the Second Merger” beginning on page 18) will be subject to U.S. federal income tax only in limited circumstances.

For additional discussion of material U.S. federal income tax consequences of the First Merger and the Second Merger, see the section entitled “Material U.S. Federal Income Tax Consequences of the Pre-Closing Merger, the Pre-Closing Conversion, the First Merger and the Second Merger” beginning on page 18.

Section 367(a) of the Code generally requires a U.S. holder of stock in a U.S. corporation to recognize gain (but not loss) when such stock is exchanged for stock of a non-U.S. corporation in an exchange that would otherwise qualify for nonrecognition treatment, unless certain conditions are satisfied. Although it is currently expected that these conditions will be satisfied, U.S. holders are cautioned that the potential application of Section 367(a) of the Code to the First Merger and the Second Merger is complex and depends on factors that cannot be determined until the closing of the First Merger and the Second Merger and the interpretation of legal authorities and facts relating to the First Merger and the Second Merger. Accordingly, there can be no assurance that the IRS will not take the position that Section 367(a) applies to cause U.S. holders to recognize the full amount of any gain as a result of the First Merger and the Second Merger or that a court will not agree with such a position of the IRS in the event of litigation. U.S. holders should consult with their tax advisors regarding the potential application of Section 367(a) of the Code in their particular situation.

For additional discussion of material U.S. federal income tax consequences of the First Merger and the Second Merger, see the section entitled “Material U.S. Federal Income Tax Consequences of the Pre-Closing Merger, the Pre-Closing Conversion, the First Merger and the Second Merger” beginning on page 18.

Cantel Stockholders (only to the extent it relates to Irish tax consequences, as defined in the section entitled “Material Ireland Tax Consequences of the First Merger”) that are resident or ordinarily resident for tax purposes in Ireland, or Cantel Stockholders that use, hold or acquire their shares of Cantel Common Stock (or Canyon Newco Common Stock immediately following the Pre-Closing Merger) for the purposes of a trade carried on by that person in Ireland through a branch or agency, or otherwise for the purposes of a branch or agency in Ireland will, subject to the availability of any exemptions and reliefs, generally be subject to Irish tax on taxable gains arising on the cancellation of their shares of Canyon Newco Common Stock pursuant to the First Merger. The receipt by a Cantel Stockholder of cash only (e.g., if they do not vote in favor of the adoption of the Merger Agreement at the Special Meeting) will be treated as a disposal of his or her shares of Cantel Common Stock for the purposes of Irish capital gains tax or corporation tax on taxable gains (as applicable), which is referred to as Irish CGT, and such holder which is resident or ordinarily resident for tax purposes in Ireland or who holds Cantel Common Stock in connection with a branch or agency in Ireland may, subject to the availability of any exemptions and reliefs, realize a taxable gain (or allowable loss).

It is anticipated that the First Merger should be treated as a ‘scheme of reconstruction or amalgamation’ for Irish CGT purposes and, subject to certain conditions, the following treatment should apply:

For additional discussion of certain Irish tax consequences of the First Merger, see the section entitled “Material Ireland Tax Consequences of the First Merger” beginning on page 20.

It is expected that for the majority of transfers of STERIS Shares, there will not be any Irish stamp duty. Transfers of STERIS Shares effected by means of the transfer of book-entry interests through DTC are not subject to Irish stamp duty. However, if you hold your STERIS Shares directly rather than beneficially through DTC, any transfer of your STERIS Shares could be subject to Irish stamp duty (currently at the rate of 1% of the higher of the price paid or the market value of the shares acquired).

A STERIS Shareholder who directly holds STERIS Shares may transfer such STERIS Shares into his or her own broker account to be held through DTC (or vice versa) without giving rise to Irish stamp duty provided that there is no change in the ultimate beneficial ownership of the STERIS Shares as a result of the transfer and the transfer is not in contemplation of a sale of the STERIS Shares by a beneficial owner to a third party.

Payment of Irish stamp duty is generally a legal obligation of the transferee. The potential for stamp duty could adversely affect the price of your STERIS Shares.

For additional discussion of certain Irish tax consequences of the First Merger, see the section entitled “Material Ireland Tax Consequences of the First Merger” beginning on page 20.

In certain limited circumstances, Irish dividend withholding tax, which is referred to as DWT, (which applies at a rate of 25%), may arise in respect of dividends, if any, paid on STERIS Shares. A number of exemptions from DWT exist, including exemptions pursuant to which shareholders resident in the U.S., U.K. and in the countries listed in Annex D attached to this proxy statement/prospectus, which are collectively referred to as Relevant Territories and individually as a Relevant Territory, may be entitled to exemptions from DWT.

See the section entitled “Material Ireland Tax Consequences of the First Merger” beginning on page 20 for further information on the operation of DWT generally and the relevant exemptions – in particular, please note the requirement to complete certain relevant Irish Revenue Commissioners DWT forms, which are referred to as DWT Forms, in order to qualify for many of the exemptions.

Dividends paid in respect of STERIS Shares that are owned by a U.S. resident and held through DTC should not be subject to DWT provided that the address of the beneficial owner of such STERIS Shares in the records of the broker holding such STERIS Shares is recorded as being in the United States (and such broker has further transmitted the relevant information to a qualifying intermediary appointed by STERIS).

Dividends paid in respect of STERIS Shares that are held outside of DTC by a person who is a resident of the U.S. should not be subject to DWT if such STERIS Shareholder has provided a completed IRS Form 6166 or a valid DWT Form to STERIS’s transfer agent to confirm its U.S. residence and claim an exemption.

STERIS Shareholders resident in other Relevant Territories may also be eligible for exemption from DWT on dividends paid in respect of their STERIS Shares provided that they satisfy the conditions of one of the exemptions including the requirement to furnish valid DWT Forms to their brokers (in respect of shares held through DTC) (and such broker has further transmitted the relevant information to a qualifying intermediary appointed by STERIS) or to STERIS’s transfer agent (in respect of shares held outside of DTC).

However, other STERIS Shareholders may be subject to DWT, which if you are such a STERIS Shareholder could adversely affect the price of your STERIS Shares. For additional discussion of certain Irish tax consequences of the First Merger, see the section entitled “Material Ireland Tax Consequences of the First Merger” beginning on page 20.

STERIS Shareholders that are entitled to an exemption from DWT on dividends received from STERIS should not be subject to Irish income tax in respect of those dividends, unless they have some connection with Ireland other than their shareholding in STERIS (for example, they are resident in Ireland). STERIS Shareholders who are not resident nor ordinarily resident in Ireland but who are not entitled to an exemption from DWT should generally have no further liability to Irish income tax on those dividends which suffer DWT.

For additional discussion of certain Irish tax consequences of the First Merger, see the section entitled “Material Ireland Tax Consequences of the First Merger” beginning on page 20.

Irish capital acquisitions tax, which is referred to as CAT (currently levied at a rate of 33%), could apply to a gift or inheritance of STERIS Shares irrespective of the place of residence, ordinary residence or domicile of the parties. This is because STERIS Shares will be regarded as property situated in Ireland. Gifts and inheritances passing between spouses are exempt from CAT. Children have a tax-free threshold of €335,000 in respect of taxable gifts or inheritances received from their parents. The person who receives the gift or inheritance has primary liability for CAT.

For additional discussion of certain Irish tax consequences of the First Merger, see the section entitled “Material Ireland Tax Consequences of the First Merger” beginning on page 20.

After completion of the Mergers, STERIS Shareholders may not receive dividends at the same rate they received dividends prior to the completion of the Mergers for various reasons, including the following:

After completion of the Mergers, STERIS Shareholders (including Cantel Stockholders following the Closing) will have no contractual or other legal right to dividends that have not been declared by the STERIS Board of Directors.

The COVID-19 pandemic and the resulting government mandates have had a significant impact on the global stock market and on both STERIS’s and Cantel’s operations. For as long as it continues, and in the event there is another widespread regional, national or global health epidemic or pandemic, the uncertainty may impact our ability to implement the Mergers. Additionally, the COVID-19 pandemic and the resulting government mandates and/or pandemic-related travel restrictions may cause operational challenges that result in difficulties in integrating Cantel into STERIS. As a result, STERIS may fail to realize the anticipated synergies from the Mergers. STERIS and Cantel expect that the impact of the COVID-19 pandemic and government mandates on the success of the Mergers will largely depend on the extent and duration of the pandemic, the governmental and public actions taken in response, and the effect the pandemic will have on the U.S. economy.

You should read and consider the other risk factors specific to STERIS’s businesses that will also affect STERIS after completion of the Mergers. These risks are described in Part 1, Item 1A of STERIS’s Annual Report on Form 10-K for the 2020 fiscal year and in other documents that are incorporated by reference herein. See the section entitled “Where You Can Find More Information” beginning on page 152 for the location of information incorporated by reference in this proxy statement/prospectus.

You should read and consider the other risk factors specific to Cantel’s businesses that will also affect STERIS after completion of the Mergers. These risks are described in Part 1, Item 1A of Cantel’s Annual Report on Form 10-K for the 2020 fiscal year and in other documents that are incorporated by reference herein. See the section entitled “Where You Can Find More Information” beginning on page 152 for the location of information incorporated by reference in this proxy statement/prospectus.

STERIS plc is a public limited company incorporated under the laws of Ireland on December 22, 2016. It became the parent company of the STERIS group of companies on March 28, 2019, in connection with the Redomiciliation. STERIS’s registered office is located in Dublin, Ireland and its U.S. administrative offices are located in Mentor, Ohio. STERIS is a leading provider of infection prevention and other procedural products and services. STERIS offers its Customers a unique mix of innovative capital equipment products, such as sterilizers and washers, surgical tables, lights and equipment management systems and connectivity solutions such as operating room integration; consumable products including detergents and gastrointestinal endoscopy accessories and other products and services, including equipment installation and maintenance, microbial reduction of medical devices, instrument and scope repair solutions, laboratory services and outsourced instrument reprocessing.

STERIS is segmented by Customer, with three reporting segments: Healthcare, Applied Sterilization Technologies (AST) and Life Sciences. Through these three segments STERIS serves hospitals and surgery centers, medical device manufacturers and pharmaceutical manufacturers.

STERIS Shares are listed on the NYSE, trading under the symbol “STE.”

Cantel Medical Corp. is a leading provider of infection prevention products and services in the healthcare market, specializing in the following reportable segments: Medical, Life Sciences, Dental and Dialysis. Most of Cantel’s equipment, consumables and supplies are used to help prevent the occurrence or spread of infections. Cantel’s products include specialized medical device reprocessing systems for endoscopy and renal dialysis, advanced water purification equipment, sterilants, disinfectants and cleaners, sterility assurance monitoring products for hospitals and dental clinics, disposable infection control products primarily for dental and GI endoscopy markets, instruments and instrument reprocessing workflow systems serving the dental industry, dialysate concentrates, hollow fiber membrane filtration and separation products. Additionally, Cantel provides technical service for its products. Cantel operates in four segments through wholly-owned subsidiaries in the U.S. and internationally.

Shares of Cantel Common Stock are listed on the NYSE, trading under the symbol “CMD.”

US Holdco, whose legal name is Solar New US Holding Co, LLC, serves primarily as a holding company, holding all of the membership interests in Solar New US Parent Co, LLC. In addition, US Holdco makes loans to and collects interest from affiliates.

Crystal Merger Sub, whose legal name is Crystal Merger Sub 1, LLC, is a direct, wholly owned subsidiary of US Holdco. Upon the completion of the First Merger, Crystal Merger Sub will cease to exist. Crystal Merger Sub was formed in Delaware on January 7, 2021 for the sole purpose of effectuating the First Merger.

Canyon Newco, whose legal name is Canyon HoldCo, Inc., is a Delaware corporation and direct and wholly owned subsidiary of Cantel. At the effective time of the Pre-Closing Merger, Canyon Merger Sub will merge with and into Cantel with Cantel surviving the Pre-Closing Merger as a direct and wholly owned subsidiary of Canyon Newco. Upon the completion of the First Merger, Canyon Newco will survive the First Merger as a direct and wholly owned subsidiary of US Holdco. Upon the completion of the Second Merger, Canyon Newco will cease to exist. Canyon Newco was incorporated for the purpose of facilitating the Mergers.

Canyon Merger Sub, whose legal name is Grand Canyon Merger Sub, Inc., is a Delaware corporation and a direct and wholly owned subsidiary of Canyon Newco. Upon completion of the Pre-Closing Merger, Canyon Merger Sub will cease to exist. Canyon Merger Sub was incorporated for the sole purpose of effectuating the Pre-Closing Merger.

The Special Meeting will be held on    , 2021 at      Eastern Time. In light of the public health impact of COVID-19 and in order to protect the health and well-being of our stockholders, the Special Meeting will be held virtually via live webcast at www.virtualshareholdermeeting.com/CMD2021SM. There will be no physical in-person meeting.

The purpose of the Special Meeting is as follows:

Cantel will transact no other business at the Special Meeting.

The Cantel Board of Directors recommends that Cantel Stockholders vote:

See the section entitled “The Mergers—Recommendation of the Cantel Board of Directors and Reasons for the Mergers” beginning on page 56.

Only holders of record of issued and outstanding shares of Cantel Common Stock as of the close of business on    , 2021, the Record Date for the Special Meeting, are entitled to notice of, and to vote at, the Special Meeting.

A quorum of Cantel Stockholders is necessary to hold a valid meeting. A quorum will exist at the Special Meeting with respect to each matter to be considered at the Special Meeting if the holders of a majority of shares of Cantel Common Stock outstanding and entitled to vote on the Record Date are present in person virtually or represented by proxy at the Special Meeting. All shares represented by proxy are counted as present for purposes of establishing a quorum, including abstentions. Under the NYSE rules, brokers who hold shares in “street name” for a beneficial owner of those shares typically have the authority to vote in their discretion on “routine” proposals when they have not received instructions from beneficial owners. However, brokers are not allowed to exercise their voting discretion with respect to the approval of proposals that the NYSE determines to be “non-routine” and will not vote on such proposals if the broker has not received instructions from the beneficial owners on how to vote on the proposals. Under the NYSE rules, brokers are not permitted to vote on any of the matters to be considered at the Special Meeting. As a result, if you are the beneficial owner of shares of Cantel Common Stock held of record by your bank, broker or nominee, your shares will not be voted on any matter unless you affirmatively instruct your bank, broker or other nominee how to vote your shares in one of the ways indicated by your bank, broker or other nominee.

If you submit a properly executed proxy card, even if you do not vote for some or all of the proposals or vote to “ABSTAIN” in respect of some or all of the proposals, your shares of Cantel Common Stock will be counted for purposes of calculating whether a quorum is present at the Special Meeting with respect to each matter to be considered at the Special Meeting. Executed but unvoted proxies will be voted in accordance with the recommendations of the Cantel Board of Directors. If additional votes must be solicited to approve the Cantel Merger Proposal, the Special Meeting will be adjourned to solicit additional proxies. Shares of Cantel Common Stock held in street name will be counted as present for the purpose of determining the existence of a quorum at the Special Meeting so long as a stockholder has given the broker or other nominee voting instructions on at least one of the proposals brought before the Special Meeting. The proposals for consideration at the Special

Meeting are considered “non-routine” matters under NYSE Rule 452, and, therefore, no broker non-votes can occur at the Special Meeting. Cantel Stockholder’s shares will not be counted as present for the purpose of determining the existence of a quorum if no instructions have been provided on how to vote on any such proposals.

Approval of the Cantel Merger Proposal requires the affirmative vote of a majority of the shares of Cantel Common Stock outstanding as of the close of business on the record date and entitled to vote on the proposal. Abstentions will have the same effect as a vote “AGAINST” the Cantel Merger Proposal.

Approval of the Compensation Proposal requires the affirmative vote of a majority of the shares of Cantel Common Stock present in person virtually or by proxy at the Special Meeting and entitled to vote on the proposal. Abstentions will have the same effect as a vote “AGAINST” the Compensation Proposal.

The matters to be voted on at the Special Meeting are described in the section entitled “Cantel Special Meeting Proposals” beginning on page 49.

Under the Cantel Bylaws, whether or not there is a quorum, the chairman of the Special Meeting may adjourn the Special Meeting, and may elect to do so to, among other things, solicit additional proxies if there are not sufficient votes at the time of the Special Meeting in favor of the Cantel Merger Proposal.

Cantel Stockholders holding shares directly as stockholders of record may vote via the Internet by going to the web address provided on the enclosed proxy card and following the instructions for Internet voting; by telephone using the toll-free telephone number listed on the enclosed proxy card; or by completing, signing, dating and returning the enclosed proxy card in the postage-paid envelope provided.

Cantel Stockholders of record may vote their shares while attending the meeting virtually or by submitting their proxies:

Cantel Stockholders whose shares are held in “street name” by a bank, broker, nominee, fiduciary or other custodian should refer to the proxy card, voting instruction form or other information forwarded by their bank, broker, nominee, fiduciary or other custodian for instructions on how to vote their shares.

Shares of Cantel Common Stock held directly in your name as stockholder of record as of the close of business on the Record Date may be voted virtually at the Special Meeting. If you choose to vote your shares of Cantel Common Stock virtually at the Special Meeting, you will need the sixteen-digit control number included on your proxy card or on the instructions accompanying the proxy statement/prospectus mailed to you in order to enter the Special Meeting. Even if you plan to virtually attend the Special Meeting, the Cantel Board of Directors recommends that you vote your shares in advance as described below so that your vote will be counted if you later decide not to virtually attend the Special Meeting.

If your shares of Cantel Common Stock are held in “street name,” then the bank, broker or other nominee is considered the stockholder of record for purposes of voting at the Special Meeting. If you hold shares beneficially in street name, you may vote by submitting voting instructions to your bank, broker or other nominee. For directions on how to vote shares held beneficially in street name, please refer to the voting instruction card provided by your bank, broker or other nominee.

If you hold your shares of Cantel Common Stock directly as the stockholder of record you may direct your vote by proxy without virtually attending the Special Meeting. You can vote by proxy via the Internet, by telephone or by mail by following the instructions provided in the enclosed proxy card.

Cantel Stockholders whose shares of Cantel Common Stock are held in “street name” by a bank, broker, nominee, fiduciary or other custodian should refer to the proxy card, voting instruction form or other information forwarded by their bank, broker, nominee, fiduciary or other custodian for instructions on how to vote their shares of Cantel Common Stock.

If you have any questions about how to vote or direct a vote in respect of your shares of Cantel Common Stock, you may contact MacKenzie, Cantel’s proxy solicitor, via email at proxy@mackenziepartners.com or at:

If you are a Cantel Stockholder of record as of the close of business on the Record Date, whether you vote via the Internet, by telephone or mail, you can change or revoke your proxy before it is voted at the Special Meeting in one of the following ways:

If you are a beneficial owner of Cantel Common Stock as of the close of business on the Record Date, you must follow the instructions of your bank, broker or other nominee to revoke or change your voting instructions.

The enclosed proxy card is being solicited on behalf of the Cantel Board of Directors. In addition to solicitation by mail, Cantel’s directors, officers and employees may solicit proxies in person, by telephone or by electronic means. These persons will not be specifically compensated for doing this.

Cantel has retained MacKenzie to assist in the solicitation process. Cantel will pay MacKenzie a fee of approximately $30,000, as well as reasonable and documented out-of-pocket expenses. Cantel also has agreed to indemnify MacKenzie against various liabilities and expenses that relate to or arise out of its solicitation of proxies (subject to certain exceptions).

Cantel will ask banks, brokers and other custodians, nominees and fiduciaries to forward the proxy solicitation materials to the beneficial owners of shares of Cantel Common Stock held of record as of the close of business on the Record Date by such nominee holders. Cantel will reimburse these nominee holders for their customary clerical and mailing expenses incurred in forwarding the proxy solicitation materials to beneficial owners of Cantel Common Stock.

The matters to be considered at the Special Meeting are of great importance to Cantel Stockholders. Accordingly, you are urged to read and carefully consider the information contained in or incorporated by reference into this proxy statement/prospectus and submit your proxy via the Internet or by telephone or complete, date, sign and promptly return the enclosed proxy card in the enclosed postage-paid envelope. If you submit your proxy via the Internet or by telephone, you do not need to return the enclosed proxy card.

As of November 2, 2020, Cantel directors and executive officers, and their affiliates, as a group, were entitled to vote or had shared power to vote a total of 4,522,560 shares of Cantel Common Stock, or approximately 10.7% of the total shares of Cantel Common Stock issued and outstanding as of

November 2, 2020. Two such directors, Charles M. Diker and Mark N. Diker, have entered into the Voting Agreement with STERIS, US Holdco and Crystal Merger Sub, pursuant to which they have agreed, among other things, to vote all of the shares of Cantel Common Stock beneficially owned by them (constituting approximately 10.4% of the issued and outstanding shares of Cantel Common Stock as of January 8, 2021), in favor of the Cantel Merger Proposal and other items, on the terms and subject to the conditions set forth in the Voting Agreement. For more information, see the section entitled “Voting Agreement” beginning on page 94.

Cantel currently expects that all of its directors and executive officers will vote their shares “FOR” the Cantel Merger Proposal and “FOR” the Compensation Proposal.

You are entitled to attend the Special Meeting virtually only if you were a Cantel Stockholder of record as of the close of business on the Record Date or you held your shares of Cantel Common Stock beneficially in the name of a bank, broker or other nominee as of the Record Date or you hold a valid proxy for the Special Meeting.

If you were a Cantel Stockholder of record at the close of business on the Record Date and wish to attend the Special Meeting, please so indicate on the appropriate proxy card or as prompted by the Internet or telephone voting system. You will need the sixteen-digit control number included on your individual proxy card or on the instructions accompanying your proxy statement/prospectus in order to enter the Special Meeting. If you do not present such sixteen-digit control number, you might not be admitted to the Special Meeting.

If a bank, broker or other nominee is the record owner of your shares of Cantel Common Stock, you will not be permitted to virtually attend the Special Meeting unless you first obtain a legal proxy issued in your name from the record owner and register in advance to participate in the Special Meeting. To register, you must forward a copy of such legal proxy, along with your email address, to Broadridge. You will receive confirmation of your registration, with a control number and additional instructions on how to vote at the Special Meeting, by email from Broadridge. You are encouraged to request a legal proxy from your bank, broker or other nominee promptly as the process can be lengthy.

The preliminary voting results will be announced at the Special Meeting. In addition, within four business days following the Special Meeting, Cantel intends to report the final voting results in a Current Report on Form 8-K filed with the SEC. If the final voting results have not been certified within such four-business-day period, Cantel will report the preliminary voting results in a Current Report on Form 8-K at that time and will file an amendment to the Current Report on Form 8-K to report the final voting results within four business days of the date that the final results are certified.

CANTEL STOCKHOLDERS SHOULD CAREFULLY READ THIS PROXY STATEMENT/PROSPECTUS IN ITS ENTIRETY FOR MORE DETAILED INFORMATION CONCERNING THE CANTEL MERGER PROPOSAL AND THE OTHER MATTERS TO BE VOTED ON AT THE SPECIAL MEETING.

It is a condition to the completion of the Mergers that Cantel Stockholders adopt the Merger Agreement and approve the transactions contemplated by the Merger Agreement. The consideration that Cantel Stockholders will receive upon completion of the Mergers is subject to potential adjustments, as set forth in the Merger Agreement, which are described in the section entitled “The Merger Agreement—Merger Consideration” beginning on page 80.

The approval by such Cantel Stockholders of the Cantel Merger Proposal is required by Section 251 of the DGCL and is a condition to the completion of the Mergers.

Approval of the Cantel Merger Proposal requires the affirmative vote of a majority of the shares of Cantel Common Stock outstanding as of the close of business on the Record Date and entitled to vote. Abstentions will have the same effect as a vote “AGAINST” the proposal.

The Cantel Board of Directors recommends that you vote “FOR” the Cantel Merger Proposal.

As required by Section 14A of the Exchange Act and the applicable SEC rules issued thereunder, which were enacted pursuant to the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010, Cantel is required to provide its stockholders an opportunity to vote to approve, on a non-binding, advisory basis, certain compensation that may be paid or become payable to Cantel’s named executive officers that is based on or otherwise relates to the Mergers, as described in the section entitled “The Mergers Interests of Cantel Directors and Executive Officers in the Mergers” beginning on page 74. Accordingly, Cantel Stockholders are being provided the opportunity to cast an advisory vote on such potential payments.

As an advisory vote, this proposal is not binding upon Cantel or the Cantel Board of Directors and approval of the Compensation Proposal is not a condition to the completion of the Mergers. Because the executive compensation to be paid in connection with the Mergers is based on the terms of the Merger Agreement as well as contractual arrangements with Cantel’s named executive officers, such compensation will be payable, regardless of the outcome of this advisory vote, if the Merger Agreement is adopted (subject only to the contractual conditions applicable thereto). However, Cantel seeks the support of its stockholders and believes that stockholder support is appropriate because Cantel has a comprehensive executive compensation program designed to link the compensation of its executives with Cantel’s performance and the interests of Cantel Stockholders. Accordingly, Cantel Stockholders are being asked to vote on the following resolution:

Approval of the non-binding Compensation Proposal requires the affirmative vote of a majority of the shares of Cantel Common Stock present in person virtually or by proxy at the Special Meeting and entitled to vote on the proposal. Abstentions will have the same effect as a vote “AGAINST” the proposal.

The Cantel Board of Directors recommends that you vote “FOR” the Compensation Proposal.

of the Pre-Closing Merger and who properly demand, and do not lose their right to seek, appraisal of their shares of Cantel Common Stock in compliance with the requirements of Section 262 of the DGCL will be entitled to exercise appraisal rights in connection with the Pre-Closing Merger under Section 262 of the DGCL. This means that holders of shares of Cantel Common Stock who may exercise appraisal rights and who also have properly exercised, perfected and not waived, effectively withdrawn or otherwise lost those appraisal rights are entitled to have their shares of Cantel Common Stock appraised by the Delaware Court of Chancery and to receive payment in cash of the “fair value” of their shares of Cantel Common Stock, exclusive of any element of value arising from the accomplishment or expectation of the Pre-Closing Merger or the First Merger, together with interest (subject to certain exceptions) to be paid on the amount determined to be fair value, if any, as determined by the Delaware Court of Chancery, so long as those holders comply exactly with the procedures established by Section 262 of the DGCL. For additional information about appraisal rights, see the section entitled “Appraisal Rights of Cantel Stockholders” contained in this proxy statement/prospectus and the text of Section 262 of the DGCL attached hereto as Annex C.

If, between the date of the Merger Agreement and the effective time of the First Merger, the number of issued and outstanding shares of Cantel Common Stock, Canyon Newco Common Stock or STERIS Shares changes by reason of any stock split, reverse stock split, stock dividend (including any dividend or distribution of securities convertible into Cantel Common Stock, Canyon Newco Common Stock or STERIS Shares, as applicable), reorganization, recapitalization, reclassification, combination, exchange of shares or other like change, the Merger Consideration shall be adjusted appropriately.

Based upon the closing sale price of STERIS Shares on NYSE of $    on    , 2021, the last practicable trading date prior to the date of this proxy statement/prospectus, the value of the Merger Consideration was approximately $     .

From time to time, as part of Cantel’s ongoing efforts to strengthen its overall business and enhance value for its stockholders, customers and other stakeholders, Cantel’s management and the Cantel Board of Directors evaluate strategic alternatives for Cantel’s business, taking into account Cantel’s performance, strategy, risks and position, as well as economic, regulatory, competitive and other conditions. As part of this effort, Mr. Charles M. Diker, Chairman of the Cantel Board of Directors, and Mr. George L. Fotiades, the Chief Executive Officer and a member of the Cantel Board of Directors, regularly engage in discussions with the Chief Executive Officers of other companies across Cantel’s business segments, including Medical, Dental and Life Sciences.

From time to time over the past several years, Mr. Fotiades and Mr. Walter M Rosebrough, Jr., the President and Chief Executive Officer and a member of the STERIS Board of Directors, have had informal discussions regarding developments within each company’s respective businesses, including in February and March 2020. During the course of these discussions, Mr. Rosebrough had on multiple occasions expressed to Mr. Fotiades an interest in exploring a strategic business combination transaction between the two companies. No substantive or specific transaction terms were discussed during any such discussions.

Between April and August 2020, various strategic and financial parties reached out to Cantel, either directly or through Centerview to express possible interest in an acquisition of Cantel, or certain of its divisions.

During the STERIS Board of Directors meeting held in July, 2020, certain members of STERIS management presented information to the STERIS Board of Directors regarding, among other things, Cantel as potential acquisition target of STERIS.

On September 28, 2020, Mr. Rosebrough called Mr. Fotiades to discuss STERIS’s continued interest in pursuing a potential acquisition of Cantel by STERIS. On September 29, 2020, Mr. Fotiades informed Mr. Rosebrough that he intended to have a discussion with the Cantel Board of Directors regarding strategic options for Cantel at a meeting scheduled for October 7, 2020.

Prior to the October 7, 2020 Cantel Board of Directors meeting, Mr. Fotiades discussed the inbound interest received from various parties, including STERIS’s interest, with Mr. Diker and Mr. Alan R. Batkin, Lead Independent Director of Cantel. In light of these conversations and the outreach from these parties earlier in the year, the three directors believed that it would be beneficial to discuss the inbound expressions of interest with the full Cantel Board of Directors. During a meeting of the Cantel Board of Directors on October 7, 2020, the Cantel Board of Directors authorized Centerview to continue discussions with STERIS, and other select parties,

to explore potential strategic transactions. During the course of October and November, Centerview engaged in discussions with five strategic counterparties, including STERIS (the “Strategic Bidders”) and two private equity counterparties (the “Financial Bidders”).

On October 8, 2020, Mr. Rosebrough and Mr. Fotiades held a telephonic discussion during which Mr. Fotiades confirmed that the Cantel Board of Directors was interested in continuing discussions with STERIS, among others.

On October 12, 2020, representatives of Centerview and representatives of Guggenheim Securities LLC (“Guggenheim”), STERIS’s financial advisor, discussed potential preliminary diligence and process considerations for the parties to assess further interest in a potential transaction.

On October 13, 2020, Mr. Rosebrough called Mr. Fotiades to express his disappointment that Cantel had elected to pursue a process with multiple bidders instead of exclusively with STERIS. Mr. Rosebrough expressed preliminary interest in participating in the proposed process, but agreed to follow up shortly to confirm.

On October 15, 2020, Mr. Rosebrough called Mr. Fotiades to confirm that STERIS was interested in continuing the discussions and would participate in a process if that was what the Cantel Board of Directors decided to pursue.

Between October 19, 2020 and November 14, 2020, Cantel entered into confidentiality agreements with a total of five prospective buyers, including three of the Strategic Bidders (including a confidentiality agreement entered with STERIS on October 26, 2020) and both Financial Bidders. The other two Strategic Bidders declined to enter into confidentiality agreements with Cantel. During this time, one of the parties that had reached out between April and August 2020 and that had previously communicated its interest to Mr. Fotiades in acquiring Cantel’s medical business, indicated that it was not prepared to proceed with an acquisition of the entire company.

On October 22, 2020, Cantel pre-announced the estimated revenue range for its first fiscal quarter, ending on October 31, 2020, of $290 - $295 million, an increase of approximately 25% sequentially from the prior quarter and a year over year increase of approximately 14% on a reported basis. The intraday high for Cantel Common Stock on the NYSE was $53.16 per share, and the closing price per share of Cantel Common Stock on that date was $51.82 per share, an increase of approximately 8.1% over the previous day’s closing price.

On October 27, 2020, during a meeting of the STERIS Board of Directors, representatives of Guggenheim gave a presentation to the STERIS Board of Directors concerning, among other things, Cantel as a potential acquisition target of STERIS.

On November 5, 2020, the Cantel Board of Directors convened a telephonic conference, which also was attended by representatives of Centerview and Wachtell, Lipton, Rosen & Katz (“Wachtell Lipton”), Cantel’s legal counsel. Mr. Diker, explained to the Cantel Board of Directors that senior management of Cantel, in consultation with Centerview, had determined to seek approval from the Cantel Board of Directors to initiate a process involving the potential sale of the company. Mr. Fotiades provided additional background on his discussions with Centerview and the prospective buyers who had shown interest in participating in such a process. Representatives of Wachtell Lipton advised the Cantel Board of Directors of their fiduciary and confidentiality obligations in connection with a potential offer by any participants in the process. Representatives of Centerview then provided additional detail regarding each of the parties who had expressed interest in participating in the potential sale process.

On November 11, 2020, Mr. Fotiades and other members of Cantel’s senior management participated in a management presentation to members of STERIS’s senior management by videoconference. In addition to Mr. Fotiades, the videoconference was attended by Peter Clifford, Cantel’s President and Chief Operating Officer, Shaun Blakeman, Cantel’s Senior Vice President and Chief Financial Officer, and Seth M. Yellin, Cantel’s Executive Vice President and Chief Growth Officer.

Between November 16, 2020 and November 20, 2020, at the direction of the Cantel Board of Directors, representatives of Centerview distributed a process letter regarding preliminary indications of interests to

two Strategic Bidders, including STERIS (the third Strategic Bidder that had signed a confidentiality agreement had by this time indicated that it was not interested in pursuing a potential transaction), and both Financial Bidders. Each of the counterparties were also provided access to a virtual data room with limited public and private information about Cantel.

On December 2, 2020, STERIS submitted a letter of intent to Cantel, which contemplated an all-stock acquisition at a fixed exchange ratio of 0.325 STERIS Shares per share of Cantel Common Stock and implied a purchase price of $62.66 per share based on STERIS’s closing price as of December 1, 2020. Cantel did not receive indications of interest from the other Strategic Bidder or the Financial Bidders.

On December 4, 2020, Mr. Fotiades informed Mr. Rosebrough that Cantel had rejected STERIS’s offer. In response, Mr. Rosebrough asked Mr. Fotiades to schedule a phone call to further discuss STERIS’s offer.

On December 5, 2020, Mr. Fotiades and Mr. Rosebrough had a telephonic discussion in which Mr. Rosebrough asked Mr. Fotiades for guidance as to the changes to STERIS’s proposal that would be required for the Cantel Board of Directors to approve a transaction with STERIS. Mr. Fotiades responded that Cantel was expecting a value per share of Cantel Common Stock at a premium to its 52-week high, which was then approximately $79.50 per share.

On December 7, 2020, Mr. Rosebrough called Mr. Fotiades to inform him that STERIS would be submitting an offer at $75 per share the following day.

On December 8, 2020, Cantel announced its earnings for its first quarter of fiscal year 2021. Cantel reported first quarter 2021 net sales of $297 million, up 15.5% compared to the prior year. The intraday high for Cantel Common Stock on the NYSE was $76 per share, and the closing price per share of Cantel Common Stock on that date was $75.10 per share, an increase of approximately 22% over the previous day’s closing price. In the afternoon of December 8, 2020, STERIS submitted a revised letter of intent to Cantel, which valued Cantel Common Stock at $75 per share and contemplated mixed consideration consisting of between 60% and 75% stock consideration and 40% and 25% cash consideration. The revised letter of intent stated that STERIS’s offer was conditioned upon Cantel granting STERIS a 45-day exclusivity period in which to finalize and enter into definitive documentation for the proposed transaction. Later that day, Messrs. Diker, Fotiades and Batkin discussed the new inbound offer.

On December 9, 2020, the Cantel Board of Directors convened a telephonic conference, which also was attended by representatives of Centerview. Centerview provided an update to the Cantel Board of Directors regarding the sale process and the revised offer received by STERIS. The Cantel Board of Directors discussed STERIS’s offer in light of the significant increase in the price per share of Cantel Common Stock that occurred following Cantel’s first quarter earnings announcement. Representatives of Centerview reviewed with the directors Cantel’s historical and projected financials and referred to these financials in its financial analysis of various strategic alternatives, including separate analysis of Cantel’s Medical, Dental and Life Sciences businesses. Centerview also provided a pro forma financial profile of the combined company giving effect to the STERIS transaction. Messrs. Diker and Fotiades discussed next steps and Cantel’s strategy in responding to STERIS’s revised offer and request for exclusivity. After discussion, the Cantel Board of Directors authorized the continuation of discussions with STERIS and authorized Mr. Fotiades to make a counter proposal to Mr. Rosebrough of a purchase price of $83 per share of Cantel Common Stock in exchange for an exclusivity and diligence period of four weeks.

On the evening of December 9, 2020, Mr. Fotiades called Mr. Rosebrough to relay the counter proposal approved by the Cantel Board of Directors. Mr. Fotiades requested that STERIS’s final offer be made to Cantel in writing no later than December 11, 2020.

On December 11, 2020, Mr. Rosebrough informed Mr. Fotiades that STERIS was prepared to raise its offer to a purchase price of $78.75 per share of Cantel Common Stock, but that STERIS could not increase its offer any further. Mr. Rosebrough indicated that the consideration would consist of approximately 80% stock consideration and 20% cash consideration. The closing price per share of Cantel Common Stock on the NYSE on that date was $74.46 per share. Mr. Rosebrough indicated that STERIS would aim to negotiate and announce a definitive merger agreement with Cantel by the time of the J.P. Morgan 39th Annual Healthcare Conference, scheduled for January 11, 2021 through January 14, 2021 (the “J.P. Morgan Conference”).

On December 12, 2020, the Cantel Board of Directors convened a telephonic conference. Mr. Fotiades informed the Cantel Board of Directors of his discussion with Mr. Rosebrough. Mr. Fotiades also informed the Cantel Board of Directors of the targeted announcement date during the week of January 11, 2021. After discussion, the Cantel Board of Directors authorized Mr. Fotiades to pursue the revised proposal and continue the discussions with STERIS.

On December 13, 2020, STERIS submitted a further revised letter of intent to Cantel, which reflected the revised offer communicated by Mr. Rosebrough of a purchase price of $78.75 per share of Cantel Common Stock, consisting of 80% stock consideration and 20% cash consideration. The letter of intent contained a request to enter into a 30-day exclusivity period. STERIS indicated that it would work with Cantel to enter into a definitive agreement within that period.

On December 15, 2020, Cantel and STERIS entered into an exclusivity agreement that would remain in effect through January 11, 2021.

On December 16, 2020, an expanded virtual data room with additional information about Cantel was opened, and access was granted to STERIS and its advisors.

Between December 16, 2020 and January 4, 2021, STERIS and Cantel undertook reciprocal due diligence investigations, including through diligence meetings between members of management of each company on commercial, operational, legal, tax and financial topics.

On December 29, 2020, the audit committee of the STERIS Board of Directors met by videoconference with members of management and Guggenheim to discuss aspects of the proposed merger consideration that STERIS would pay in connection with a transaction with Cantel.

On January 2, 2021, Wachtell Lipton sent to Jones Day (“Jones Day”), STERIS’s legal counsel, an initial draft of the proposed merger agreement.

On January 4, 2021, the audit committee of the STERIS Board of Directors conducted a videoconference that was attended by all other STERIS Directors, members of STERIS management, and Guggenheim. Guggenheim presented a preliminary financial analysis of the proposed transaction with Cantel and STERIS management reviewed its preliminary cost synergy analysis.

On January 5, 2021, Jones Day sent to Wachtell Lipton a revised draft of the merger agreement, containing a number of proposed changes, including revisions restricting the Cantel Board of Director’s ability to change its recommendation in support of a transaction with STERIS, increasing the size of a termination fee payable by Cantel under certain circumstances, revising the regulatory clearance framework and expanding Cantel’s cooperation requirements (including with respect to financing). The revised draft also contemplated that Mr. Diker, Mr. Mark N. Diker, a member of the Cantel Board of Directors, and Diker Management LLC would enter into a voting agreement pursuant to which they would agree to vote in favor of and take other actions in furtherance of the transaction in their capacities as Cantel Stockholders. The revised draft also rejected Cantel’s proposal that STERIS add one member of the Cantel Board of Directors to the STERIS Board of Directors following the closing of the Mergers.

On January 6, 2021, the Cantel Board of Directors convened a telephonic conference, which was attended by representatives of Centerview, to discuss the status of discussions with respect to the proposed transaction with STERIS. Members of management reviewed with the Cantel Board of Directors the results of the commercial, operational, tax, financial and legal due diligence on STERIS that had been conducted to date, including through virtual meetings held between management members of both companies. The Cantel Board of Directors and Centerview discussed the financial terms of STERIS’s proposal in light of the price per share of Cantel Common Stock and Cantel’s diligence findings with respect to STERIS.

On January 6, 2021, Mr. Fotiades contacted Mr. Rosebrough to inform him that the Cantel Board of Directors would be willing to entertain a proposal with a purchase price of at least $85 per share of Cantel Common Stock.

On the morning January 8, 2021, Wachtell Lipton sent Jones Day a revised draft of the merger agreement. In addition, throughout the course of January 8, Cantel provided additional information regarding employee and other due diligence matters.

On the evening of January 8, 2021, the STERIS Board of Directors met by videoconference to discuss the status of discussions between the parties and to review the terms of the proposed merger agreement. The meeting was also attended by members of the STERIS senior management, U.S. and Irish outside legal counsel, and Guggenheim. During the meeting, the STERIS Board of Directors discussed their fiduciary duties and the transaction terms with legal counsel, discussed the strategic fit and integration of Cantel with management, and discussed the financial analysis of the transaction with Guggenheim.

On the morning of January 9, 2021, Mr. Rosebrough contacted Mr. Fotiades to inform him that STERIS would be willing to increase its proposed merger consideration to $84.00, consisting of approximately 80% stock consideration and 20% cash consideration, per share of Cantel Common Stock.

Later on January 9, 2021, the Cantel Board of Directors convened a telephonic conference, which was attended by representatives of Centerview and Wachtell Lipton. Mr. Fotiades informed the Cantel Board of Directors of his discussion with Mr. Rosebrough. After the discussion, the Cantel Board of Directors authorized Mr. Fotiades to make a counterproposal to Mr. Rosebrough of $85.75 per share of Cantel Common Stock.

Later on January 9, 2021, Mr. Rosebrough informed Mr. Fotiades that STERIS would be willing to increase its proposed merger consideration to $84.50 (based on the closing price of STERIS Shares on the NYSE of $202.81 on January 8, 2021), consisting of 0.33332 STERIS Shares and $16.90 in cash per share of Cantel Common Stock, subject to the satisfactory resolution of certain key outstanding issues.

Throughout the day on January 9, 2021, representatives of Wachtell Lipton and Jones Day held calls to discuss the key outstanding issues. Throughout the course of January 9, Cantel continued to provide additional information regarding employee and other due diligence matters, and representatives of Wachtell Lipton, Jones Day and members of the management teams of both STERIS and Cantel met to discuss matters related to the merger agreement.

Early in the day on January 10, 2021, Jones Day and Wachtell Lipton continued to exchange drafts of the merger agreement and have discussions regarding the proposed terms. Later in the day, Mr. Jeff Z. Mann, Cantel’s Senior Vice President and General Counsel, and Mr. J. Adam Zangerle, STERIS’s Senior Vice President and General Counsel, held a telephonic discussion and sought to reach mutual agreement on the remaining key outstanding issues, but were unable to do so ahead of the parties’ respective board meetings scheduled for later that evening.

In the evening of January 10, 2021, the STERIS Board of Directors convened a videoconference, which was attended by representatives of Guggenheim and Jones Day, to discuss the status of the negotiations and the apparent impasse that had been reached between the parties. During the meeting Mr. Zangerle informed the STERIS Board of Directors of his discussion with Mr. Mann. Following that meeting, Mr. Rosebrough contacted Mr. Fotiades to inform him that STERIS would be pausing its engagement with Cantel on the proposed transaction because STERIS did not believe the parties would be in a position to reach mutual agreement on each of the remaining key outstanding issues and be prepared to announce the transaction ahead of the Needham Virtual Growth Conference (the “Needham Conference”), at which Mr. Rosebrough was scheduled to speak at on January 11, 2021.

Mr. Fotiades informed the Cantel Board of Directors of his discussion with Mr. Rosebrough during a telephonic conference that had been convened in the evening of January 10, 2021 to discuss the proposed transaction with STERIS and the key outstanding issues, which was attended by representatives of Centerview and Wachtell Lipton. The Cantel Board of Directors discussed this information and instructed Mr. Fotiades to respond that Cantel was prepared to accept STERIS’s proposal with respect to the regulatory clearance framework and reach agreement on the remaining issues in order to announce the transaction the following morning, but could not assure STERIS that it would remain interested in pursuing a transaction with STERIS if agreement was not reached in that timeframe. Mr. Fotiades telephoned Mr. Rosebrough to pass along this message and also expressed concern that certain members of the press had made inbound inquiries with respect to a possible transaction between STERIS and Cantel. Mr. Rosebrough responded that STERIS would not be in a position to reach agreement and sign definitive documents within that time period. Mr. Rosebrough also noted the pendency of the Needham Conference and the J.P. Morgan Conference. Later in the evening of January 10, 2021, Mr. Mann telephoned Mr. Zangerle. Mr. Zangerle suggested to Mr. Mann that there was a possibility that STERIS would be interested to resume negotiations later during the week.

After receiving direction from STERIS management, on January 11, 2021, a representative of Jones Day informed a representative of Wachtell Lipton that STERIS wished to reengage with Cantel regarding the proposed transaction. The Jones Day representative later called a representative of Wachtell Lipton and noted that, in light of market movements that day, STERIS would be willing to increase the Merger Consideration from $84.50 to $84.66 (based on the closing price of STERIS Shares on the NYSE of $200.46 on January 11, 2021), consisting of 0.33787 STERIS Shares and $16.93 in cash per share of Cantel Common Stock, subject to the resolution of all other key outstanding issues in line with STERIS’s prior proposal. The parties agreed to target announcement of the transaction on the morning of January 12, 2021. Following this time, Jones Day and Wachtell Lipton continued to exchange drafts of the merger agreement and have discussions regarding the proposed terms and ultimately reached resolutions with respect to the remaining issues.

Later on January 11, 2021, the Cantel Board of Directors convened a telephonic conference, which was attended by representatives of Centerview and Wachtell Lipton. The Cantel Board of Directors discussed the implied value of the Merger Consideration to be received by holders of shares of Cantel Common Stock, Cantel’s standalone prospects and the synergies expected to result from the transaction. Wachtell Lipton provided a summary of the proposed Merger Agreement and discussed with the Cantel Board of Directors various legal matters relevant to the consideration of the proposed Merger Agreement by the Cantel Board of Directors. Members of management briefed the Cantel Board of Directors on the findings and conclusions of the due diligence process. Representatives of Centerview reviewed with the Cantel Board of Directors Centerview’s financial analysis of the Merger Consideration, and rendered to the Cantel Board of Directors an oral opinion, which was subsequently confirmed by delivery of a written opinion dated January 12, 2021, that as of such date and based upon and subject to various assumptions made, procedures followed, matters considered, and qualifications and limitations upon the review undertaken in preparing its opinion, the Merger Consideration to be paid to holders of shares of Cantel Common Stock (other than as specified in such opinion) pursuant to the Merger Agreement was fair, from a financial point of view, to such holders. Centerview’s opinion is more fully described below under the caption “The Mergers—Opinion of Cantel’s Financial Advisor” beginning on page 60 of this proxy statement/prospectus and the full text of the written opinion of Centerview, which set forth the factors, assumptions, limitations and qualifications in such opinion, is attached as Annex B hereto. After further consideration, the Cantel Board of Directors unanimously resolved that the Merger Agreement and the transactions contemplated by the Merger Agreement were advisable, fair to and in the best interests of Cantel Stockholders. The Cantel Board of Directors then unanimously voted to approve the Merger Agreement and the transactions contemplated by the Merger Agreement, and resolved to recommend that Cantel Stockholders approve the Merger Agreement. The Cantel Board of Directors authorized the appropriate officers of Cantel to finalize, execute and deliver the Merger Agreement and related documentation.

In the evening of January 11, 2021, Eastern Time, the STERIS Board of Directors convened a videoconference, which was attended by representatives of Guggenheim and Jones Day, and unanimously approved the terms of the Merger Agreement.

In the early morning of January 12, 2021, Cantel and STERIS executed the Merger Agreement and STERIS, Charles M. Diker, Mark N. Diker and Diker Management LLC executed the Voting Agreement. The execution of the Merger Agreement was announced later that morning.

By unanimous vote, the Cantel Board of Directors, at a special meeting held on January 11, 2021: (a) resolved that the Merger Agreement and the transactions contemplated by the Merger Agreement, including the Mergers, are fair and in the best interests of Cantel and Cantel Stockholders; (b) approved and declared advisable the Merger Agreement and the transactions contemplated by the Merger Agreement, including the Mergers on the terms and subject to the conditions set forth in the Merger Agreement, in accordance with the requirements of the DGCL and directed that the Merger Agreement be submitted for adoption at the Special Meeting; and (c) resolved to recommend that Cantel Stockholders adopt the Merger Agreement and approve the transactions contemplated by the Merger Agreement, including the Mergers. The Cantel Board of Directors unanimously recommends that you vote “FOR” the Cantel Merger Proposal and “FOR” Compensation Proposal.

In evaluating the Mergers, the Cantel Board of Directors consulted with Cantel’s senior management team, as well as Cantel’s outside legal and financial advisors, and, in reaching its decision to approve the Merger

Agreement and declare its advisability and to recommend that Cantel Stockholders vote in favor of the Cantel Merger Proposal, the Cantel Board of Directors considered a number of factors, including, but not limited to, the following:

The Cantel Board of Directors also considered a number of potentially negative factors in its deliberations concerning the Merger Agreement and the Mergers, including:

In the judgment of Cantel’s Board of Directors, however, these potential risks were more than offset by the potential benefits of the Mergers discussed above.

The foregoing discussion of the information and factors considered by the Cantel Board of Directors is not intended to be exhaustive, but includes the material factors that the Cantel Board of Directors considered. In reaching its decision to approve the Merger Agreement, the Mergers, and the other transactions contemplated by the Merger Agreement, the Cantel Board of Directors did not quantify or assign any relative weights to the factors considered, and individual directors may have given different weights to different factors. The Cantel Board of Directors considered all these factors as a whole, and overall considered the factors to be favorable to, and to support, its determination. The Cantel Board of Directors conducted an overall review of the factors described above, and reached the consensus that the Merger Agreement, the Mergers, and the other transactions contemplated by the Merger Agreement are fair to, advisable to, and in the best interests of, Cantel and Cantel Stockholders.

In considering the recommendation of the Cantel Board of Directors to adopt the Merger Agreement, Cantel Stockholders should be aware that the executive officers and directors of Cantel have certain interests in the

Mergers that may be different from, or in addition to, the interests of Cantel Stockholders generally, as more fully described below under the section captioned “—Interests of Cantel Directors and Executive Officers in the Mergers.” The Cantel Board of Directors was aware of these interests and considered them when adopting the Merger Agreement and recommending that Cantel Stockholders vote in favor of the Cantel Merger Proposal.

On January 11, 2021, Centerview rendered to the Cantel Board of Directors its oral opinion, subsequently confirmed in a written opinion dated January 12, 2021, that, as of such date and based upon and subject to various assumptions made, procedures followed, matters considered, and qualifications and limitations upon the review undertaken by Centerview in preparing its opinion, the Merger Consideration to be paid to the holders of shares of Cantel Common Stock (other than Excluded Shares) pursuant to the Merger Agreement was fair, from a financial point of view, to such holders.

The full text of Centerview’s written opinion, dated January 12, 2021, which describes the assumptions made, procedures followed, matters considered, and qualifications and limitations upon the review undertaken by Centerview in preparing its opinion, is attached as Annex B and is incorporated herein by reference. The summary of the written opinion of Centerview set forth below is qualified in its entirety to the full text of Centerview’s written opinion attached as Annex B. Centerview’s financial advisory services and opinion were provided for the information and assistance of the Cantel Board of Directors (in their capacity as directors and not in any other capacity) in connection with and for purposes of its consideration of a transaction, including the transactions contemplated by the Merger Agreement, and Centerview’s opinion only addressed the fairness, from a financial point of view, as of the date thereof, to the holders of shares of Cantel Common Stock (other than Excluded Shares) of the Merger Consideration to be paid to such holders pursuant to the Merger Agreement. Centerview’s opinion did not address any other term or aspect of the Merger Agreement or the transactions contemplated by the Merger Agreement and does not constitute a recommendation to any Cantel Stockholder or any other person as to how such Cantel Stockholder or other person should vote with respect to the Mergers or otherwise act with respect to the transactions contemplated by the Merger Agreement or any other matter.

The full text of Centerview’s written opinion should be read carefully in its entirety for a description of the assumptions made, procedures followed, matters considered, and qualifications and limitations upon the review undertaken by Centerview in preparing its opinion.

In connection with rendering the opinion described above and performing its related financial analyses, Centerview reviewed, among other things:

Centerview also participated in discussions with members of the senior management and representatives of Cantel regarding their assessment of the Cantel Data (including the Cantel Forecast), and the STERIS Forecasts and members of the senior management and representatives of STERIS regarding their assessment of the STERIS Data and the Synergies, and the strategic rationale for the transactions contemplated by the Merger Agreement. In addition, Centerview reviewed publicly available financial and stock market data, including valuation multiples, for Cantel and STERIS and compared that data with similar data for certain other companies, the securities of which are publicly traded, in lines of business that Centerview deemed relevant. Centerview also compared certain of the proposed financial terms of the transactions contemplated by the Merger Agreement with the financial terms, to the extent publicly available, of certain other transactions that Centerview deemed relevant, and conducted such other financial studies and analyses and took into account such other information as Centerview deemed appropriate.

Centerview assumed, without independent verification or any responsibility therefor, the accuracy and completeness of the financial, legal, regulatory, tax, accounting and other information supplied to, discussed with, or reviewed by Centerview for purposes of its opinion and, with Cantel’s consent, Centerview relied upon such information as being complete and accurate. In that regard, Centerview assumed, at Cantel’s direction, that the Cantel Data (including, without limitation, the Cantel Forecast) and the STERIS Forecasts were reasonably prepared on bases reflecting the best currently available estimates and judgments of the management of Cantel as to the matters covered thereby, and that the STERIS Data and the Synergies were reasonably prepared on bases reflecting the best currently available estimates and judgments of the management of STERIS as to the matters covered thereby; and Centerview relied, at Cantel’s direction, on the Cantel Data (including, without limitation, the Cantel Forecast), the STERIS Data, the STERIS Forecasts and the Synergies for purposes of Centerview’s analysis and opinion. Centerview expressed no view or opinion as to the Cantel Data (including, without limitation, the Cantel Forecast), the STERIS Forecasts, the STERIS Data and the Synergies or the assumptions on which they were based. In addition, at Cantel’s direction, Centerview did not make any independent evaluation or appraisal of any of the assets or liabilities (contingent, derivative, off-balance-sheet or otherwise) of Cantel or STERIS, nor was Centerview furnished with any such evaluation or appraisal, and was not asked to conduct, and did not conduct, a physical inspection of the properties or assets of Cantel or STERIS. Centerview assumed, at Cantel’s direction, that the final executed Merger Agreement would not differ in any respect material to Centerview’s analysis or opinion from the Draft Merger Agreement reviewed by Centerview. Centerview also assumed, at Cantel’s direction, that the transactions contemplated by the Merger Agreement will be consummated on the terms set forth in the Merger Agreement and in accordance with all applicable laws and other relevant documents or requirements, without delay or the waiver, modification or amendment of any term, condition or agreement, the effect of which would be material to Centerview’s analysis or Centerview’s opinion, and that, in the course of obtaining the necessary governmental, regulatory and other approvals, consents, releases and waivers for the transactions contemplated by the Merger Agreement, no delay, limitation, restriction, condition or other change, including any divestiture requirements or amendments or modifications, will be imposed, the effect of which would be material to Centerview’s analysis or Centerview’s opinion. Centerview also assumed that the transactions contemplated by the Merger Agreement will have certain tax consequences as described in discussions with representatives of Cantel. Centerview did not evaluate and did not express any opinion as to the solvency or fair value of Cantel or STERIS, or the ability of Cantel or STERIS to pay their respective obligations when they come due, or as to the impact of the transactions contemplated by the Merger Agreement on such matters, under any state, federal or other laws relating to bankruptcy, insolvency or similar matters. Centerview is not a legal, regulatory, tax or accounting advisor, and Centerview expressed no opinion as to any legal, regulatory, tax or accounting matters.

Centerview’s opinion expressed no view as to, and did not address, Cantel’s underlying business decision to proceed with or effect the transactions contemplated by the Merger Agreement, or the relative merits of the transactions contemplated by the Merger Agreement as compared to any alternative business strategies or transactions that might be available to Cantel or in which Cantel might engage. Centerview’s opinion was limited to and addressed only the fairness, from a financial point of view, as of the date of Centerview’s written opinion, to the holders of the shares of Cantel Common Stock (other than Excluded Shares) of the Merger Consideration to be paid to such holders pursuant to the Merger Agreement. For purposes of its opinion, Centerview was not

asked to, and Centerview did not, express any view on, and its opinion did not address, any other term or aspect of the Merger Agreement or the transactions contemplated by the Merger Agreement, including, without limitation, the structure or form of the transactions contemplated by the Merger Agreement, or any other agreements or arrangements contemplated by the Merger Agreement or entered into in connection with or otherwise contemplated by the transactions contemplated by the Merger Agreement, including, without limitation, the fairness of the transactions contemplated by the Merger Agreement or any other term or aspect of the transactions contemplated by the Merger Agreement to, or any consideration to be received in connection therewith by, or the impact of the transactions contemplated by the Merger Agreement on, the holders of any other class of securities, creditors or other constituencies of Cantel or any other party. In addition, Centerview expressed no view or opinion as to the fairness (financial or otherwise) of the amount, nature or any other aspect of any compensation to be paid or payable to any of the officers, directors or employees of Cantel or any party, or class of such persons in connection with the transactions contemplated by the Merger Agreement, whether relative to the Merger Consideration to be paid to the holders of the shares of Cantel Common Stock (other than Excluded Shares) pursuant to the Merger Agreement or otherwise. Centerview’s opinion was necessarily based on financial, economic, monetary, currency, market and other conditions and circumstances as in effect on, and the information made available to Centerview as of, the date of Centerview’s written opinion, and Centerview does not have any obligation or responsibility to update, revise or reaffirm its opinion based on circumstances, developments or events occurring after the date of Centerview’s written opinion. Centerview expressed no view or opinion as to what the value of STERIS Shares actually will be when issued pursuant to the First Merger or the prices at which the shares of Cantel Common Stock or STERIS Shares will trade or otherwise be transferable at any time, including following the announcement or consummation of the transactions contemplated by the Merger Agreement. Centerview’s opinion does not constitute a recommendation to any Cantel Stockholder or any other person as to how such Cantel Stockholder or other person should vote with respect to the Mergers or otherwise act with respect to the transactions contemplated by the Merger Agreement or any other matter. Centerview’s financial advisory services and its written opinion were provided for the information and assistance of the Cantel Board of Directors (in their capacity as directors and not in any other capacity) in connection with and for purposes of its consideration of the transactions contemplated by the Merger Agreement. The issuance of Centerview’s opinion was approved by the Centerview Partners LLC Fairness Opinion Committee.

The following is a summary of the material financial analyses prepared and reviewed with the Cantel Board of Directors in connection with Centerview’s opinion, dated January 12, 2021. The summary set forth below does not purport to be a complete description of the financial analyses performed or factors considered by, and underlying the opinion of, Centerview, nor does the order of the financial analyses described represent the relative importance or weight given to those financial analyses by Centerview. Centerview may have deemed various assumptions more or less probable than other assumptions, so the reference ranges resulting from any particular portion of the analyses summarized below should not be taken to be Centerview’s view of the actual value of Cantel or STERIS. Some of the summaries of the financial analyses set forth below include information presented in tabular format. In order to fully understand the financial analyses, the tables must be read together with the text of each summary, as the tables alone do not constitute a complete description of the financial analyses performed by Centerview. Considering the data in the tables below without considering all financial analyses or factors or the full narrative description of such analyses or factors, including the methodologies and assumptions underlying such analyses or factors, could create a misleading or incomplete view of the processes underlying Centerview’s financial analyses and its opinion. In performing its analyses, Centerview made numerous assumptions with respect to industry performance, general business and economic conditions and other matters, many of which are beyond the control of Cantel, STERIS or any other party to the transactions contemplated by the Merger Agreement. None of Cantel, STERIS or Centerview, or any other person, assumes responsibility if future results are materially different from those discussed. Any estimates contained in these analyses are not necessarily indicative of actual values or predictive of future results or values, which may be significantly more or less favorable than as set forth below. In addition, analyses relating to the value of Cantel or STERIS do not purport to be appraisals or reflect the prices at which Cantel or STERIS may actually be sold. Accordingly, the assumptions and estimates used in, and the results derived from, the financial analyses are inherently subject to

substantial uncertainty. Except as otherwise noted, the following quantitative information, to the extent that it is based on market data, is based on market data as it existed on or before January 11, 2021 (the last trading day before the public announcement of the Merger Agreement) and is not necessarily indicative of current market conditions.

Centerview reviewed and compared certain financial information, ratios and multiples for Cantel to corresponding financial information, ratios and multiples for publicly traded companies that Centerview deemed comparable, based on its experience and professional judgment, to Cantel, which selected publicly traded companies are referred to in this summary of Centerview’s opinion as the selected Cantel comparison companies. The selected companies consisted of:

Although none of the selected Cantel comparison companies is directly comparable to Cantel, these companies were selected, among other reasons, because they are publicly traded companies with certain operational and financial characteristics, which, for purposes of its analyses, Centerview considered to be similar to those of Cantel. However, because none of the selected Cantel comparison companies is exactly the same as Cantel, Centerview believed that it was inappropriate to, and therefore did not, rely solely on the quantitative results of the selected public company analysis. Accordingly, Centerview also made qualitative judgments, based on its experience and professional judgment, concerning differences between the business, financial and operating characteristics and prospects of Cantel and the selected Cantel comparison companies that could affect the public trading values of each in order to provide a context in which to consider the results of the quantitative analysis.

Using publicly available information obtained from SEC filings and other data sources and closing stock prices as of January 11, 2021, Centerview calculated, for each selected Cantel comparison company the following figures, ratios and multiples: (i) market value of common equity (determined using the treasury stock method and taking into account outstanding in-the-money options, other equity awards and other convertible securities, as applicable), (ii) enterprise value (calculated as the market value of common equity determined using the treasury stock method and taking into account outstanding in-the-money options, other equity awards and other convertible securities, as applicable, plus debt and less cash, after giving effect to certain adjustments for minority interest and contingent consideration), (iii) enterprise value as a multiple of Wall Street research analyst consensus estimated earnings before interest, taxes, depreciation and amortization, or EBITDA, for calendar year 2021 (calculated as the EBITDA adjusted for any acquisition-related costs and expenses, restructuring-related costs and expenses, gains or losses related to divested businesses or assets, and losses on disposal of fixed assets, which is referred to as a company’s Estimated 2021 EBITDA), (iv) projected revenue growth for the calendar year 2021 to calendar year 2022, (v) EBITDA margin for calendar year 2021 (calculated as EBITDA for the relevant period divided by revenue for the same period) and (vi) net leverage ratio as a multiple of such company’s latest twelve months, or LTM EBITDA. These analyses resulted in a median multiple of enterprise value to Estimated 2021 EBITDA of 18.8x, a median revenue growth percentage of 6%, a median EBITDA margin percentage of 23% and a median net leverage ratio of 2.4x, in each case, for such selected Cantel comparison companies.

The resulting data were as follows:

Based on its experience and professional judgment, for purposes of its analysis, Centerview selected a reference range of multiples of enterprise value to Estimated 2021 EBITDA of 15.0x to 17.5x. In selecting this reference range, Centerview made qualitative judgments based on its experience and professional judgment concerning differences between the business, financial and operating characteristics of Cantel and the selected companies that could affect their public trading values in order to provide a context in which to consider the results of the quantitative analysis. Centerview applied the EBITDA multiple reference range to Cantel’s own calendar year 2021 estimated EBITDA of $278 million as set forth in the Cantel Data to derive a range of implied enterprise values for Cantel. Centerview subtracted from this range of implied enterprise values the face value of Cantel’s net debt as of December 31, 2020 as set forth in the Cantel Data to derive a range of implied equity values for Cantel. Centerview then divided these implied equity values by the number of fully-diluted outstanding shares of Cantel Common Stock as of January 8, 2021, as set forth in the Cantel Data, to derive a range of implied per share equity values. Centerview also applied the EBITDA multiple reference range to the Estimated 2021 EBITDA of Cantel of $256 million to derive a range of implied per share equity values for each share. The results of this analyses are summarized as follows: based on Cantel’s own calendar year 2021 estimated operating EBITDA of Cantel, as set forth in the Cantel Data, Centerview calculated an implied per share equity value range of approximately $76 to $91, rounded to the nearest dollar, and based on the Estimated 2021 EBITDA of Cantel, Centerview calculated an implied per share of Cantel Common Stock equity value range of approximately $69 to $82, rounded to the nearest dollar. Centerview then compared these ranges to the implied value of the Merger Consideration of $84.66 per share of Cantel Common Stock, which is based on the cash consideration of $16.93 and an implied value of $67.73 in stock consideration (based upon an exchange ratio of 0.33787 and the closing price of STERIS Shares as of January 11, 2021) per share of Cantel Common Stock, which is referred to as the Implied Value, to be paid to the holders of shares of Cantel Common Stock (other than Excluded Shares) pursuant to the Merger Agreement.

Centerview reviewed and compared certain information relating to the following selected transactions involving target companies serving the Medical, Dental, or Life Sciences markets with similar business characteristics and financial profiles to Cantel (which are referred to as the selected transactions in this Summary of Centerview Financial Analysis) that Centerview, based on its experience and professional judgment, deemed relevant to consider in relation to Cantel and the Mergers and the other transactions contemplated by the Merger Agreement.

Although none of the selected transactions is directly comparable to the Mergers and the other transactions contemplated by the Merger Agreement, the transactions listed below were chosen by Centerview because, among other reasons, their participants, size or other factors, for purposes of Centerview’s analysis, may be considered similar to the Mergers and the other transactions contemplated by the Merger Agreement. Centerview used its experience, expertise and knowledge of these industries to select transactions that involved companies with certain operational, business or financial characteristics that, for purposes of this analysis, may be considered similar to those of Cantel. However, because none of the selected transactions used in this analysis is identical or directly comparable to the Mergers and the other transactions contemplated by the Merger Agreement, Centerview believed that it was inappropriate to, and therefore did not, rely solely on the quantitative

results of the selected precedent transaction analysis. Accordingly, Centerview also made qualitative judgments, based on its experience and professional judgment, concerning differences between the operational, business or financial characteristics of Cantel and each target company as well as the Mergers and the other transactions contemplated by the Merger Agreement and the selected transactions that could affect the transaction values of each in order to provide a context in which to consider the results of the quantitative analysis.

Using publicly available information obtained from SEC filings and other data sources, Centerview calculated, for each selected transaction, among other things, (i) the enterprise value implied for the applicable target company based on the consideration payable in the applicable selected transactions, as a multiple of the target company’s EBITDA for the most recently ended twelve months prior to the announcement of such selected transaction, or LTM EBITDA (in the case of Key Surgical, LTM EBIT as disclosed in SEC filings) and (ii) the enterprise value implied for the applicable target company based on the consideration payable in the applicable selected transactions, as a multiple of the target company’s EBITDA for the twelve months following the announcement of such selected transaction, or NTM EBITDA. This analysis resulted in a median multiple of enterprise value to LTM EBITDA of 15.9x and a median multiple of enterprise value to NTM EBITDA of 15.0x for such selected transactions.

The resulting data were as follows:

Based on its analysis and other considerations that Centerview deemed relevant in its professional judgment and experience, Centerview selected reference ranges of multiples of enterprise value to LTM EBITDA of 16.0x to 19.0x and of enterprise value to NTM EBITDA of 14.5x to 18.0x. In selecting these ranges, Centerview made qualitative judgments based on its experience and professional judgment concerning differences between the business, financial and operating characteristics and prospects of Cantel and the companies included in the selected transactions as well as the Mergers and the other transactions contemplated by the Merger Agreement and the selected transactions and other factors that could affect each transaction or the public trading, acquisition or other values of such companies or Cantel in order to provide a context in which to consider the results of the quantitative analysis.

Centerview applied these reference ranges to Cantel’s enterprise value as a multiple of its LTM EBITDA of $193 million and as a multiple of its NTM EBITDA of $278 million, respectively, each as set forth in the Cantel Data, to derive ranges of implied enterprise values for Cantel. Centerview subtracted from these ranges of implied enterprise values the face value of Cantel’s net debt as of December 31, 2020 (including expected change of control costs related to contingent consideration payments that may become due under the terms of prior Cantel transaction agreements and make-whole payments payable to holders of Cantel’s 3.25% senior unsecured convertible notes due 2025) as set forth in the Cantel Data to derive a range of implied equity values for Cantel. Centerview then divided these implied equity values by the number of fully-diluted outstanding shares of Cantel Common Stock as of January 8, 2021 as set forth in the Cantel Data to derive a range of implied per share equity value for each share of approximately $53 to $65 based on LTM EBITDA, rounded to the nearest dollar, and a range of implied per share equity value for each share of approximately $72 to $93 based on NTM EBITDA, rounded to the nearest dollar. Centerview then compared these ranges to the Implied Value, to be paid to the holders of shares of Cantel Common Stock (other than Excluded Shares) pursuant to the Merger Agreement.

Centerview performed a discounted cash flow analysis of Cantel based on the Cantel Forecast, which is a traditional valuation methodology used to derive a valuation of an asset by calculating the “present value” of estimated future cash flows of the asset. “Present value” refers to the current value of future cash flows and is obtained by discounting those future cash flows by a discount rate that takes into account macroeconomic assumptions and estimates of risk, the opportunity cost of capital, expected returns and other appropriate factors.

In performing this analysis, Centerview calculated a range of illustrative equity values for Cantel by applying a discount rate range of 9.25% to 10.00% (reflecting Centerview’s analysis of Cantel’s weighted average cost of capital) and the mid-year convention to (a) Cantel’s management plan forecast as of January 4, 2021 of after-tax unlevered free cash flows of Cantel for the fiscal half-year ending July 31, 2021 and for the fiscal years 2022 through 2025 utilizing the Cantel Forecast at the direction of Cantel and assumptions discussed with Cantel management and (b) a range of illustrative terminal values for Cantel, calculated by Centerview applying perpetuity growth rates ranging from 3.75% to 4.50%, which Centerview selected based on its professional judgment, to Cantel’s after-tax unlevered free cash flows for the terminal year. Centerview then divided these implied equity values by the number of fully-diluted outstanding shares of Cantel Common Stock as of January 8, 2021, as set forth in the Cantel Data, to derive a range of implied per share equity value of approximately $67 to $91, rounded to the nearest dollar. Centerview then compared these ranges to the implied value of the Merger Consideration of $84.66 per share based on a cash consideration of $16.93 and $67.73 stock consideration per share (based upon an exchange ratio of 0.33787 and the closing price of STERIS Shares as of January 11, 2021), to be paid to the holders of shares of Cantel Common Stock (other than Excluded Shares) pursuant to the Merger Agreement.

Centerview noted for the Cantel Board of Directors certain additional factors solely for informational purposes, including, among other things, the following:

Centerview reviewed and compared the market price and implied trading multiples of the STERIS Shares with the market prices and implied trading multiples of the publicly traded securities of certain public companies in the medical devices sector, which selected publicly traded companies are referred to in this summary of Centerview’s opinion as the selected STERIS comparison companies, in each case based on publicly available research analyst estimates for STERIS and such selected STERIS comparison companies.

The selected STERIS comparison companies reviewed included the following:

Using publicly available information obtained from SEC filings and other data sources and closing stock prices as of January 11, 2021, Centerview calculated, for each selected STERIS comparison company, its equity market value as a multiple of its Estimated 2021 EBITDA.

The resulting data were as follows:

Based on its experience and professional judgment, for purposes of its analysis, Centerview selected a reference range of multiples of enterprise value to Estimated 2021 EBITDA of 18.0x to 21.0x. In selecting this reference range, Centerview made qualitative judgments based on its experience and professional judgment concerning differences between the business, financial and operating characteristics of STERIS and the selected STERIS comparison companies that could affect their public trading values in order to provide a context in which to consider the results of the quantitative analysis. Centerview applied the EBITDA multiple reference range Cantel’s estimate of calendar year 2021 operating EBITDA of STERIS of $925 million, as set forth in the STERIS Forecasts prepared by management of Cantel, to derive a range of implied per STERIS Share equity value of approximately $176 to $208.

Centerview performed a discounted cash flow analysis of STERIS based on the STERIS Forecasts prepared by management of Cantel. In performing this analysis, Centerview calculated a range of illustrative equity values for STERIS by applying a discount rate range of 7.50% to 8.25% (reflecting Centerview’s analysis of STERIS’s weighted average cost of capital) and the mid-year convention to (a) after-tax unlevered free cash flows of STERIS for the fiscal quarter ending March 31, 2021 and fiscal years 2022 through 2026 utilizing the STERIS Forecasts prepared by management of Cantel at the direction of Cantel and assumptions discussed with Cantel management and (b) a range of illustrative terminal values for STERIS, calculated by Centerview applying perpetuity growth rates ranging from 3.75% to 4.50%, which Centerview selected based on its professional judgment, to STERIS’s after-tax unlevered free cash flows for the terminal year, in each case, utilizing the STERIS Forecasts prepared by the management of Cantel. Centerview then divided these implied equity values by the number of fully-diluted outstanding STERIS Shares as of January 8, 2021, as set forth in the STERIS Data, to derive a range of implied per STERIS Share equity value of approximately $158 to $239, rounded to the nearest dollar.

Centerview noted for the Cantel Board of Directors certain additional factors solely for informational purposes, including, among other things, the following:

The preparation of a financial opinion is a complex analytical process involving various determinations as to the most appropriate and relevant methods of financial analysis and the application of those methods to the particular circumstances and, therefore, a financial opinion is not readily susceptible to summary description. In arriving at its opinion, Centerview did not draw, in isolation, conclusions from or with regard to any factor or analysis that it considered. Rather, Centerview made its determination as to fairness on the basis of its experience and professional judgment after considering the results of all of the analyses.

Centerview’s financial analyses and opinion were only one of many factors taken into consideration by the Cantel Board of Directors in its evaluation of the transactions contemplated by the Merger Agreement. Consequently, the analyses described above should not be viewed as determinative of the views of the Cantel Board of Directors or management of Cantel with respect to the Merger Consideration or as to whether the Cantel Board of Directors would have been willing to determine that a different consideration was fair. The Merger Consideration was determined through arm’s-length negotiations between Cantel and STERIS and was approved by the Cantel Board of Directors. Centerview provided advice to Cantel during these negotiations. Centerview did not, however, recommend any specific amount of consideration to Cantel or the Cantel Board of Directors or that any specific amount of consideration constituted the only appropriate consideration for the transactions contemplated by the Merger Agreement.

Centerview is a securities firm engaged directly and through affiliates and related persons in a number of investment banking, financial advisory and merchant banking activities. In the two years prior to the date of its written opinion, Centerview was engaged to provide financial advisory services to Cantel, including in connection with certain strategic matters, for which Centerview did not receive compensation during such period. In the two years prior to the date of its written opinion, Centerview had not been engaged to provide financial advisory or other services to STERIS, and Centerview did not receive any compensation from STERIS during such period. Centerview may provide investment banking and other services to or with respect to Cantel or STERIS or their respective affiliates in the future, for which Centerview may receive compensation. Certain (i) of Centerview’s and its affiliates’ respective affiliates, directors, officers, members and employees, or family members of such persons, (ii) of Centerview’s affiliates or related investment funds and (iii) investment funds or

other persons in which any of the foregoing may have financial interests or with which they may co-invest, may at any time acquire, hold, sell or trade, in debt, equity and other securities or financial instruments (including derivatives, bank loans or other obligations) of, or investments in, Cantel, STERIS, or any of their respective affiliates, or any other party that may be involved in the transactions contemplated by the Merger Agreement.

The Cantel Board of Directors selected Centerview as its financial advisor in connection with a transaction, including the transactions contemplated by the Merger Agreement, based on Centerview’s advising the Cantel Board of Directors on strategic matters for approximately the past two years and Centerview’s strong knowledge of Cantel and the industries in which Cantel competes. Centerview is an internationally recognized investment banking firm that has substantial experience in transactions similar to the transactions contemplated by the Merger Agreement.

In connection with Centerview’s services as the financial advisor to the Cantel Board of Directors, Cantel has agreed to pay Centerview an aggregate fee of approximately $67 million, $2.5 million of which was payable upon the rendering of Centerview’s opinion and the remainder of which is payable contingent upon consummation of the Mergers. In addition, Cantel has agreed to reimburse certain of Centerview’s expenses arising, and to indemnify Centerview against certain liabilities that may arise, out of Centerview’s engagement.

Cantel does not, as a matter of course, publicly disclose long-term consolidated forecasts as to future performance, earnings or other results given, among other reasons, the uncertainty, unpredictability and subjectivity of the underlying assumptions and estimates. In connection with the Cantel Board of Directors’ consideration of the transactions contemplated by the Merger Agreement, Cantel’s management prepared the Cantel Forecast based on certain unaudited financial projections regarding Cantel’s future performance for the years 2021 through 2025 on a standalone basis without giving effect to the Mergers and provided the Cantel Forecast to the Cantel Board of Directors. The Cantel Forecast also was provided by Cantel management to STERIS, and to Centerview in connection with its analyses and opinion described in the section “The Mergers—Opinion of Cantel’s Financial Advisor” beginning on page 60. The Cantel Forecast is based upon the internal financial model that Cantel’s management has historically used in connection with strategic planning.

The summaries of these projections are being included in this proxy statement/prospectus to give Cantel Stockholders access to non-public information that was provided to the Cantel Board of Directors in the course of evaluating the Mergers, and are not intended to influence your decision whether to vote in favor of the Cantel Merger Proposal or any other proposal at the Special Meeting. The inclusion of this information should not be regarded as an indication that any of Cantel, STERIS or their respective advisors or other representatives or any other recipient of this information considered, or now considers, it to be necessarily predictive of actual future performance or events, or that it should be construed as financial guidance, and such summary projections set forth below should not be relied on as such.

While presented with numeric specificity, the Cantel Forecast reflects numerous estimates and assumptions that are inherently uncertain and may be beyond the control of Cantel, including, among others, Cantel’s assumptions about healthcare markets, manufacturing and sales volume and growth levels, operating results, the success of key commercial initiatives and new product introductions, competitive conditions, technology, availability of capital resources, levels of capital expenditures, and other contractual obligations, supply and demand for, and the price of, infection prevention and control products and services, and other products or services, and other matters described in the sections entitled “Cautionary Statement Concerning Forward-Looking Statements,” “Where You Can Find More Information” and “Risk Factors,” beginning on pages 29, 152 and 31, respectively. The Cantel Forecast reflects both assumptions as to certain business decisions that are subject to change and, in many respects, subjective judgment, and thus is susceptible to multiple interpretations and periodic revisions based on actual experience and business developments. Neither Cantel nor STERIS can give any assurance that the Cantel Forecast and Cantel’s underlying estimates and assumptions will be realized. In addition, since the Cantel Forecast covers multiple years, such information by its nature becomes more speculative with each successive year. This information constitutes “forward-looking statements” and actual results may differ materially and adversely from those projected.

The Cantel Forecast was not prepared by Cantel with a view toward public disclosure, nor was it prepared with a view toward compliance with GAAP, published guidelines of the SEC or the guidelines established by the

Public Company Accounting Oversight Board for preparation and presentation of prospective financial information. Neither of Cantel’s nor STERIS’s independent registered public accounting firm, nor any other independent accountants, has compiled, examined or performed any procedures with respect to the Cantel Forecast contained herein, nor have they expressed any opinion or any other form of assurance on such information or its achievability and assume no responsibility for, and disclaim any association with, the prospective financial information. The report of the independent registered public accounting firm to Cantel contained in the Annual Report on Form 10-K for the year ended July 31, 2020, which is incorporated by reference into this proxy statement/prospectus, relates to historical financial information of Cantel, and such report does not extend to the projections included below and should not be read to do so.

Furthermore, the Cantel Forecast prepared by Cantel does not take into account any circumstances, transactions or events occurring after the date it was prepared. Neither Cantel nor STERIS can give any assurance that, had the Cantel Forecast been prepared as of the date of this proxy statement/prospectus, similar estimates and assumptions would be used by Cantel. Except as required by applicable law, neither Cantel nor STERIS intends to, and each disclaims any obligation to, make publicly available any update or other revision to the Cantel Forecast to reflect circumstances existing since its preparation or to reflect the occurrence of unanticipated events, even in the event that any or all of the underlying assumptions are shown to be in error or to reflect changes in general economic or industry conditions. The Cantel Forecast was prepared by Cantel on a standalone basis, without giving effect to the Mergers and as if Cantel never contemplated the Mergers, and does not take into account any of the possible financial and other effects on Cantel of the Mergers, the effect on Cantel of any business or strategic decision or action that has been or will be taken as a result of the Merger Agreement having been executed, or the effect of any business or strategic decisions or actions which would likely have been taken if the Merger Agreement had not been executed, but which were instead altered, accelerated, postponed or not taken in anticipation of the Mergers. Further, the Cantel Forecast does not take into account the effect on Cantel of any possible failure of the Mergers to occur. None of Cantel, STERIS or their respective affiliates, officers, directors, advisors or other representatives has made, makes or is authorized in the future to make any representation to any Cantel Stockholder or other person regarding Cantel’s ultimate performance compared to the information contained in the Cantel Forecast or to the effect that the forecasted results will be achieved. The inclusion of the Cantel Forecast herein should not be deemed an admission or representation by Cantel, STERIS or their respective advisors or any other person that it is viewed as material information of Cantel, particularly in light of the inherent risks and uncertainties associated with such forecasts.

In light of the foregoing, and considering that the Special Meeting will be held several months after the Cantel Forecast was prepared, as well as the uncertainties inherent in any forecasted information, Cantel Stockholders are cautioned not to place undue reliance on such information, and Cantel urges all Cantel Stockholders to review Cantel’s most recent SEC filings for a description of Cantel’s reported financial results. See “Where You Can Find More Information” beginning on page 152.

The following table summarizes the Cantel Forecast as of January 2021 for the fiscal years 2021 through 2025 ($ in millions):

Neither Cantel nor STERIS intends to update or otherwise revise the above Cantel Forecast to reflect circumstances existing after the date when made or to reflect the occurrence of future events, even in the event that any or all of Cantel’s assumptions underlying such Cantel Forecast are no longer appropriate, except as may be required by applicable law.

In connection with its financial analyses, Cantel’s management prepared the STERIS Forecast on a standalone basis, by reviewing (i) financial information for the completed quarterly periods of the fiscal year ending March 31, 2021, (ii) publicly available consensus estimates of Wall Street analysts for fiscal years ended March 31, 2022 and March 31, 2023 (referred to as the available consensus estimates), and (iii) directional financial trend information for the fiscal years ended March 31, 2024, March 31, 2025 and March 31, 2026 that was consistent with the available consensus estimates. Based on such information, and considering Cantel’s due diligence of STERIS , Cantel’s management made certain assumptions and prepared the STERIS Forecast based on its own projections for STERIS for the fiscal years that end March 31, 2021, March 31, 2022, March 31, 2023, March 31, 2024, March 31, 2025, and March 31, 2026. For more information on the analyses of Cantel’s financial advisor, see “The Mergers—Opinion of Cantel’s Financial Advisor” beginning on page 60.

While presented with numeric specificity, the STERIS Forecast set forth above reflects numerous estimates and assumptions by Cantel that are inherently uncertain and may be beyond the control of Cantel and STERIS. Cantel’s underlying assumptions were generally based on information and market factors known to Cantel management as of January 2021. The STERIS Forecast reflects both assumptions as to certain business decisions that are subject to change and, in many respects, subjective judgment, and thus is susceptible to multiple interpretations and periodic revisions based on actual experience and business developments. Neither Cantel nor STERIS can give any assurance that the STERIS Forecast and the underlying estimates and assumptions will be realized. In addition, since the STERIS Forecast covers multiple years, such information by its nature becomes more speculative with each successive year. This information constitutes “forward-looking statements” and actual results may differ materially and adversely from those projected.

The STERIS Forecast prepared by Cantel was not prepared with a view toward public disclosure, nor was it prepared with a view toward compliance with GAAP, published guidelines of the SEC or the guidelines established by the Public Company Accounting Oversight Board for preparation and presentation of the prospective financial information. Neither Cantel’s nor STERIS’s independent registered public accounting firm, nor any other independent accountants, have compiled, examined or performed any procedures with respect to the STERIS Forecast contained herein, nor have they expressed any opinion or any other form of assurance on such information or its achievability and assume no responsibility for, and disclaim any association with, the prospective financial information. The report of the independent registered public accounting firm to STERIS contained in the Annual Report on Form 10-K for the year ended March 31, 2020, which is incorporated by reference into this proxy statement/prospectus, relates to historical financial information of STERIS, and such report does not extend to the projections included below and should not be read to do so.

Furthermore, the STERIS Forecast prepared by Cantel does not take into account any circumstances, transactions or events occurring after the date it was prepared. Neither Cantel nor STERIS can give any assurance that, had the STERIS Forecast been prepared as of the date of this proxy statement/prospectus, similar estimates and assumptions would be used by Cantel. Except as required by applicable law, neither Cantel nor STERIS intends to, and each disclaims any obligation to, make publicly available any update or other revision to the STERIS Forecast to reflect circumstances existing since its preparation or to reflect the occurrence of unanticipated events, even in the event that any or all of the underlying assumptions are shown to be in error or to reflect changes in general economic or industry conditions. The STERIS Forecast was prepared by Cantel on a standalone basis, without giving effect to the Mergers and as if STERIS never contemplated the Mergers, and does not take into account any of the possible financial and other effects on STERIS of the Mergers, the effect on STERIS of any business or strategic decision or action that has been or will be taken as a result of the Merger Agreement having been executed, or the effect of any business or strategic decisions or actions which would likely have been taken if the Merger Agreement had not been executed, but which were instead altered, accelerated, postponed or not taken in anticipation of the Mergers. Further, the STERIS Forecast does not take

into account the effect on STERIS of any possible failure of the Mergers to occur. None of Cantel, STERIS or their respective affiliates, officers, directors, advisors or other representatives has made, makes or is authorized in the future to make any representation to any Cantel Stockholder or other person regarding STERIS’s ultimate performance compared to the information contained in the STERIS Forecast or to the effect that the forecasted results will be achieved. The inclusion of the STERIS Forecast herein should not be deemed an admission or representation by STERIS or its advisors or any other person that it is viewed as material information of STERIS, particularly in light of the inherent risks and uncertainties associated with such forecasts.

In light of the foregoing, and considering that the Special Meeting will be held several months after the STERIS Forecast was prepared, as well as the uncertainties inherent in any forecasted information, Cantel Stockholders are cautioned not to place undue reliance on such information, and all Cantel Stockholders should review STERIS’s most recent SEC filings for a description of STERIS and STERIS’s reported financial results. See “Where You Can Find More Information” beginning on page 152.

The following table summarizes the STERIS Forecast prepared by Cantel’s management as of January 2021 for the fiscal years 2021 through 2026 ($ in millions):