Item 1A.  Risk Factor s

You should carefully consider the following information about risks and uncertainties that may affect us or our business, together with the other information appearing elsewhere in this Annual Report on Form 10-K, including our consolidated financial statements and the related notes thereto. If any of the following events, described as risks, actually occur, either alone or taken together, our business, financial condition, results of operations and future growth prospects would likely be materially and adversely affected. In these circumstances, the market price of our common stock could decline, and you may lose all or part of your investment in our securities. An investment in our securities is speculative and involves a high degree of risk. You should not invest in our securities if you cannot bear the economic risk of your investment for an indefinite period of time and cannot afford to lose your entire investment. There may be additional risks that we do not presently know of or that we currently believe are immaterial which could also impair our business and financial position.

Risks Related to Our Business and Industry

We have a history of losses, and we may not achieve or maintain profitability.

We had a loss of $ 7.6 million for the fiscal year ended July 31, 201 5 , and a loss of $ 11.1 million for the fiscal year ended July 31, 201 4 . As of July 31, 201 5 , we have incurred a cumulati ve net loss of approximately $89 million. Although we expect to continue to have losses in future periods, we are unable to predict the extent of our future losses or when or if we will become profitable, and it is possible we will never become profitable. Even if we do achieve profitability, we may not be able to sustain or increase profitability on an ongoing basis.

None of our existing agreements, including with Subway, contain provisions that guarantee us any minimum revenues. If the penetration into the marketplace of silver dihydrogen citrate, or SDC, and SDC-based products is unsuccessful, revenue growth is slower than anticipated or operating expenses exceed expectations, it may take an unforeseen period of time to achieve or maintain profitability and we may never achieve or maintain profitability. Slower than anticipated revenue growth could force us to reduce research, testing, development and marketing of our technologies, and/or force us to reduce the size and scope of our operations, to sell or license our technologies to third parties, or to cease operations altogether.

The risks associated with our business may be more acute during periods of economic slowdown or recession. In addition to other consequences, these periods may be accompanied by decreased consumer and institutional spending in general, as well as decreased demand for, or additional downward pricing pressure on, our products. Accordingly, any prolonged economic slowdown or a lengthy or severe recession with respect to either the U.S. or the global economy is likely to have a material adverse effect on our results of operations, financial condition and business prospects. As a result, given the current weakness and uncertainties in the U.S. and in certain overseas economies, we expect that our business will continue to be adversely affected for so long as, and to the extent that, such adverse economic conditions and uncertainty exist.

Our future capital needs are uncertain, and we currently expect that we will need additional funds in the future which may not be available on acceptable terms or at all .  

Our capital requirements will depend on many factors, including, among other factors:

On October 23, 2015, we raised $6 million in a private placement financing of common stock and warrants to purchase common stock from Franchise Brands, LLC.  See Note 13 to the consolidated financial statements.  Therefore , as of October 28 , 2015, we believe that our current cash resources are sufficient to meet our anticipated needs during the next twelve months, however , we do not yet have, and we may never have, significant cash inflows from product sales or from other sources of revenue to offset our ongoing and planned investments in corporate infrastructure, research and development projects, regulatory submissions, business development activities, and sales and marketing, among other investments. Some or all of our ongoing or planned investments may not be successful. In addition, irrespective of our cash resources, we may be contractually or legally obligated to make certain investments, which cannot be postponed.

We expect that we will need to increase our liquidity and capital resources by one or more measures, which may include reducing operating expenses, raising additional financing in future periods through the issuance of debt, equity, or convertible securities, entering into partnerships, licenses, or other arrangements with third parties, reducing the exercise price of outstanding warrants, or through other means, any one of which could reduce the value to us, perhaps substantially, of our technology and its commercial potential. There is no guarantee that we would be able to obtain capital on terms acceptable to us, or at all. Insufficient funds would result in a material adverse effect on our business and operations and could cause us to fail to execute our business plan, fail to take advantage of future opportunities, or fail to respond to competitive pressures or customer requirements, and further may require us to delay, scale back or eliminate some or all of our research and product development programs, license to third parties the right to commercialize products or technologies that we would otherwise commercialize ourselves, or to reduce or cease operations. If adequate funds are not available when needed, we may be required to significantly modify our business model and operations to reduce spending to a sustainable level. Such modification of our business model and operations could also result in an impairment of assets which cannot be determined at this time. Furthermore, if we issue equity or convertible debt securities to raise additional funds, our existing stockholders may experience dilution, and in addition the new equity or debt securities may have rights, preferences and privileges senior to those of our existing stockholders . If we incur additional debt, it may increase our leverage relative to our earnings or to our equity capitalization.

As of October 2 8 , 201 5 , we have 55,192,630 shares of common stock issued and outstanding or reserved for issuance. Shares reserved for issuance include shares under equity compensation plans, vested and unvested options, warrants, and unvested restricted stock units. Our current authorized capital stock is limited to 100,000,000 shares of common stock and 5,000,000 shares of preferred stock. Any increase in our authorized capital stock would require the approval of a majority of our stockholders as well as the approval of our Board of Directors. If we were unable to increase our authorized capital stock for any reason, our ability to raise additional capital through the issuance of equity or convertible debt would be severely compromised and we may be unable to obtain equity or convertible debt capital at all.

Raising additional funds by issuing securities or through collaboration and licensing arrangements may cause dilution to existing stockholders, restrict our operations or require us to relinquish proprietary rights.

We expect that we will need to increase our liquidity and capital resources in future periods. We have a history of raising funds through offerings of our common stock, and we may in the future raise additional funds through public or private equity offerings, debt financings or corporate collaborations and licensing arrangements. To the extent that we raise additional capital by issuing equity securities, our stockholders’ ownership will be diluted. Additionally, any debt financing we obtain may involve covenants that restrict our operations. These restrictive covenants may include, among other things, limitations on borrowing, specific restrictions on the use of our assets, as well as prohibitions on our ability to create liens on our assets, pay dividends on or redeem our capital stock or make investments. In addition, if we raise funds through collaboration and licensing arrangements, it may be necessary to grant licenses on terms that are not favorable to us or relinquish potentially valuable rights to our products or proprietary technologies. We may be required in future collaborations to relinquish all or a portion of our sales and marketing rights with respect to our products or license intellectual property that enable licensees to develop competing products in order to complete any such transaction.

Our authorized common stock remains 100,000,000 shares. In addition to capital raising activities, other possible business and financial uses for our authorized common stock include, without limitation, future stock splits, acquiring other companies, businesses or products in exchange for shares of common stock, issuing shares of our common stock to partners in connection with strategic alliances, attracting and retaining employees by the issuance of additional securities under our various equity compensation plans, satisfying any debt we may have by issuing equity securities, or other transactions and corporate purposes that our Board of Directors, or Board, deems are in our best interest. Additionally, shares of common stock could be used for anti-takeover purposes or to delay or prevent changes in control or management of the Company. For example, without further stockholder approval, our Board could approve the sale of shares of common stock in a private transaction to purchasers who may oppose a takeover or favor our current Board. We cannot provide assurances that any issuances of common stock will be consummated on favorable terms or at all, that they will enhance stockholder value, or that they will not adversely affect our business or the trading price of our common stock.

Under our Certificate of Incorporation, our Board could also authorize the issuance of up to 5,000,000 shares of preferred stock on terms determined by the Board. If any common or preferred stock is issued, the interests of holders of our common stock could be diluted, and shares of preferred stock could be issued in a financing in which investors purchase preferred stock with rights, preferences and privileges that may be superior to those of the common stock, and the market price of our common stock could decline.

If outstanding options and warrants to purchase shares of our common stock are exercised, the interests of our stockholders could be diluted.

As of October 28 , 2015   in addition to 55,192,630 shares of common stock issued and outstanding, we had 434,218 shares reserved for issuance under equity compensation plans for vested and unv ested stock options and 3,210,000 shares reserved for issuance for vested and unvested restricted st ock units. We also had 20,368,488 shares reserved for issuance on the exercise of outstanding warrants.

We may elect to reduce the exercise price of outstanding warrants as a means of providing additional financing to us. The exercise of options and warrants, and the sale of shares underlying such options or warrants, could have an adverse effect on the market for our common stock, including the price that an investor could obtain for their shares. Investors may experience dilution in the net tangible book value of their investment upon the exercise of options and warrants currently outstanding, as well as options and warrants that may be granted or issued in the future.

Because we are an early stage company, it is difficult to evaluate our prospects and our financial results may fluctuate, which may cause our stock price to fall.

Since acquiring the rights to our SDC technology, we have encountered and likely will continue to encounter risks and difficulties associated with introducing or establishing our products in rapidly evolving markets. These risks include the following, among others:

Any failure to successfully address these risks and uncertainties could seriously harm our business and prospects. We may not succeed given the technological, marketing, strategic and competitive challenges we face. In addition, because of our limited operating history and the early stage of market development for our SDC technology, we have limited insight into trends that may emerge and affect our business. Forecasting future revenues is difficult, especially because our technology is novel, and market acceptance of our products could change rapidly. In addition, our customers and potential customers in the foreseeable future are highly concentrated. Fluctuations in the buying patterns of our current or potential customers could significantly affect the level of our sales on a period to period basis. As a result, our financial results could fluctuate to an extent that may adversely affect our stock price. There are a number of other factors that could cause our financial results to fluctuate unexpectedly, including product sales, the mix of product sales, the cost of product sales, our ability for any reason to be able to meet demand, the achievement and timing of research and development and regulatory milestones, changes in expenses, including non-cash expenses such as the fair value of stock options granted, and manufacturing or supply issues, among other factors.

A loss of one or more of our key customers could adversely affect our business.

From time to time, one or a small number of our customers may represent a significant percentage of our revenue. Our three largest customers accounted for 64% of our net product sales for the fiscal year ended July 31, 2015. Our largest customer accounted for 47% of net product sales.  No other individual customer accounted for 10% or more of our net product sales. Although we have agreements with many of our customers, these agreements typically do not prohibit customers from purchasing products and services from competitors. A decision by any of our major customers to significantly reduce the amount of product ordered or license fees paid, or their failure or inability to pay amounts owed to us in a timely manner, or at all, could have a significant adverse effect on our business.  

We are dependent on our core SDC technology and if our efforts to achieve or maintain market acceptance of our core SDC technology are not successful, we are unlikely to attain profitability.

We have and are currently focusing substantially all of our time and financial resources in the development and commercialization of our core SDC technology. We believe SDC has applications in multiple industries and we expect that sales of SDC and SDC-based products will constitute a substantial portion, or all, of our revenues in future periods. Any material decrease in the overall level of sales or expected sales of, or the prices for, SDC or SDC-based products, whether as a result of competition, change in customer demand, or any other factor, would have a materially adverse effect on our business, financial condition and results of operations. We are marketing our antimicrobial silver ion technology to industrial and consumer markets. These technologies and the products that incorporate them have not yet been accepted into the marketplace, and may never be accepted. In addition, even if our products achieve market acceptance, we may not be able to maintain product sales or other forms of revenue over time if new products or technologies are introduced that are more favorably received than our products, are more cost-effective or otherwise render our products less attractive or obsolete.

We are subject to intense competition.

Our SDC-based products compete in highly competitive markets dominated by prominent chemical and pharmaceutical companies. Most of our competitors have been in business for a longer period of time than we have, and have a greater number of products on the market and greater financial and other resources than we do. Many of our competitors already have well established brands and distribution capabilities, and in some cases are able to leverage the sale of other products with more favorable terms for products competing with our own. We also have significantly fewer employees than virtually all of our competitors. Furthermore, recent trends in this industry are for large chemical and pharmaceutical companies to consolidate into a smaller number of very large entities, which further concentrates financial, technical and market strength and increases competitive pressure in the industry. If we directly compete with these very large entities for the same markets and/or products, their financial strength could prevent us from capturing a

share of those markets. It is also possible that developments by our competitors will make our technologies or products noncompetitive or obsolete. Our ability to compete will depend upon our ability, and the ability of our distributors and other partners, to develop brand recognition and novel distribution methods, and to displace existing, established and future products in our relevant target markets. We, or our distributors and partners, may not be successful in doing so, which would have a materially adverse effect on our business, financial condition and results of operations.

We have limited sales, marketing and product distribution experience.

We have limited experience in the sales, marketing and distribution of our products. While we previously relied primarily on product distribution arrangements and/or sales and marketing services provided by third parties, we have now developed and obtained registration by the Environmental Protection Agency, or EPA, of our proprietary brand, PURE ® Hard Surface disinfectant and food contact surface sanitizer, and have resumed direct control of our sales of this product through a restructuring of our sales strategy and operations. Our new sales and marketing strategy requires that we enact various operational changes in our business, including making significant investments in our own sales and marketing organization. We intend to market and sell our PURE ® Hard Surface and related SDC-based products into consumer, commercial and institutional markets through both traditional and alternative distribution channels. Additionally, Subway has agreed to make the P URE Hard Surface disinfectant available in its franchised locations in the U.S; however, we cannot assure you whether any franchisees will choose to purchase and use the product.

We have commenced the launch of a multi-channel national sales program, which involves our development of an internal team of industry sales experts to manage each of our key channels and our deployment of contract sales representatives within each of those channels. Our current sales, distribution and marketing strategies and programs may not be successful, and we may not be able to establish the sales, marketing, and distribution capabilities necessary to directly control and manage these aspects of our operations. If we are not able to successfully sell, market and distribute these products directly, we may seek to establish product distribution arrangements with third parties, which may not be available on terms acceptable to us, if at all.

We rely on third parties to develop SDC-based products, and they may not do so successfully or diligently.

On December 11, 2013, we entered into a five-year strategic collaboration agreement with St. Louis-based Intercon Chemical Company ( “ ICC ” ) where we granted ICC distribution and certain development rights and rights to be the exclusive manufacture for all our SDC-based products.

We may also rely in part, on other third parties to whom we license rights to our technology to develop and commercialize products containing SDC for many of the applications for which we believe SDC-based products have, or may have, market opportunities.

Our reliance on ICC and other third parties for development activities reduces our control over these activities. In such arrangements, we have relied, and expect in the future to rely, on the third party to fund and direct product development activities and appropriate regulatory filings. Any of these third parties may not be able to successfully develop such SDC-based products due to, among other factors, a lack of capital, a lack of appropriate diligence, insufficient devotion to sales efforts, a change in the evaluation by the third party of the market potential for SDC-based products, technical failures, and poorer than expected results from testing or trial use of any products that may be developed. If the third parties on which we rely are not successful in such development activities, our business and operating results would be adversely affected.

If we are unable to successfully develop or commercialize new applications of our SDC technology, or if such efforts are delayed, our operating results will suffer.

In addition to its use on hard surfaces, we are pursuing potential applications of our SDC technology as a broad-spectrum antimicrobial for use as a direct food contact processing aid where it is applied as a wash for produce, meat and poultry as an intervention to prevent or kill various food-borne pathogens. Any product that may be developed in these fields may be delayed or may never achieve regulatory approval or be commercialized. Delays in achieving regulatory approvals for particular applications of our products could significantly impact our product development costs. If

indications are commercialized, we may not receive a share of future revenues that provides an adequate return on our historical or future investment.

We are dependent on third-party manufacturers, over whom we have limited control, to manufacture our products.

We do not have any manufacturing facilities ourselves and we currently rely on ICC to manufacture our SDC-based products and may in the future rely on one or more third-party manufacturers to properly manufacture our products. We may not be able to quickly replace our manufacturing capacity if ICC is unable to manufacturer our products as a result of a fire, natural disaster (including an earthquake), equipment failure or other difficulty, or if such ICC facilities are deemed not in compliance with current “good manufacturing practices,” and the noncompliance could not be rapidly rectified. ICC is our single manufacturer for our SDC-based products and may not be replaced without significant effort and delay in production. A supply interruption or an increase in demand beyond our current manufacturer’s capabilities could harm our ability to manufacturer such products until new manufacturers are identified and qualified, which would have a significant adverse effect on our business and results. Any third-party manufacturer that we find may not match our quality standards or be able to meet customer requirements.

Additionally, our inability or reduced capacity to have our products manufactured would prevent us from successfully evaluating or commercializing our proposed products. Our dependence upon third parties for the manufacture of our products may adversely affect our profit margins and our ability to develop and deliver proposed products on a timely and competitive basis.

If we are not able to manage any growth we achieve effectively, we may not become profitable.

If our efforts to achieve and maintain market acceptance of our SDC technology are successful, we will need to expand our business operations. We may not have sufficient resources to do so. If we invest in additional infrastructure, we may not be effective in expanding our operations and our systems, procedures or controls may not be adequate to support any such expansion. In addition, we would need to provide additional sales and support services to our partners, potentially in multiple markets, which we may not be able to do. Failure to properly manage increased customer demands, if any, could result in a material adverse effect on customer satisfaction, our ability to meet our contractual obligations, and our operating results.

The industries in which we operate are heavily regulated and we may be unable to compete effectively.

We are focused on the marketing and continued development of our SDC antimicrobial technology. We believe that products derived from our SDC technology, or products that may be derived from our SDC technology in future periods, require or will require approval by government agencies prior to marketing or sale in the U.S. or in foreign markets. Complying with applicable government regulations and obtaining necessary approvals can be, and has historically been, time consuming and expensive, due in part, we believe, to the novel nature of our technology. Regulatory review could involve delays or other actions adversely affecting the development, manufacture, marketing and sale of our products. While we cannot accurately predict the outcome of any pending or future regulatory review processes or the extent or impact of any future changes to legislation or regulations affecting review processes, we expect such processes to remain time consuming and expensive as we, or our partners, apply for approval to make new or additional efficacy claims for current products or to market new product formulations. Obtaining approvals for new SDC-based products in the U.S., or in markets outside the U.S., could take several years, or may never be accomplished.

SDC is a platform technology rather than a single use applied technology. As such, products developed from the platform may fall under the jurisdiction of multiple U.S. and international regulatory agencies. Our disinfectant and sanitizer products are regulated in the U.S. by the EPA. In addition to the EPA, each of the 50 United States has its own government agencies that regulate the sale or shipment of our products into their state. We have obtained registration for these products from the EPA and all states into which such products are currently marketed and sold. We are required to meet certain efficacy, toxicity and labeling requirements and pay ongoing fees in order to maintain such registrations. We may not be able to maintain these registrations in the future, which may eliminate our continued ability to market and sell our products in some or all parts of the U.S. We also may not be able to obtain necessary registrations with the

EPA and applicable states for other SDC disinfectant and sanitizer products that we or our partners may develop, which would limit our ability to sell any such products in the future.

Some potential applications of SDC, such as those aimed at healthcare, veterinary and certain food preparation markets, may require approval of other government agencies prior to marketing or sale in the U.S. or in foreign markets, such as the U.S Food and Drug Administration, or FDA, or the United States Department of Agriculture, or USDA. Obtaining FDA and/or USDA approval is a complicated and expensive process and such approvals may never be obtained for any SDC products. If FDA and/or USDA approvals are obtained, the approvals may limit the uses for which SDC products may be marketed such that they may not be profitable to us, and the applicable products would be subject to pervasive and continuing regulation by the FDA and/or USDA that could lead to withdrawal or limitation of any product approvals.

For example, in November 2014, we withdrew, without prejudice, our FCN for raw poultry due to receipt of a Deficiency Letter from the FDA stating that the agency has developed new data that is currently under review, which data calls into question the long established safety levels of the dietary intake of silver in the U.S. from food contact uses previously approved by the FDA. As a result, the FDA indicated that it would not approve our FCN absent new data or additional information that adequately addresses its new toxicity concerns.  We also received a similar Deficiency Letter from the FDA for the FCN we submitted in October 2014 for the use of SDC to reduce   Salmonella , E. coli and   Listeria   in the processing of produce. In January 2015, we withdrew, without prejudice, our produce FCN   and postponed the filing of our FCN for the use of SDC as a processing aid for beef and pork. We resubmitted our poultry FCN in June 2015. In September 2015, we received an Acknowledgement Letter from the FDA stating that our FCN for SDC as a raw poultry processing aid is complete and setting an effective date of December 2015.  Following the completion of additional testing demonstrating further reduction of silver residues to levels approaching non-detectable, and subsequent encouraging discussions held with the FDA, we resubmitted our produce FCN in September 2015.  In 2016, we expect to complete testing for the use of SDC as a processing aid for beef and pork. FCN submission is expected by mid-2016. However, if we experience any further delays in achieving regulatory approval, or, if we   failed to achieve regulatory approval of the SDC products, it would have a significant adverse effect on our business and we would most likely not be able to support our continued operations.

We intend to fund and manage certain of our EPA-regulated product development internally, in conjunction with engaging regulatory consultants and partnering with other third parties. We have partnered, or intend to partner, with third parties who are seeking, or intend to seek, approvals to market SDC-based products in markets outside the U.S., and with other third parties who are developing FDA-regulated SDC-based products who, upon such development, would seek FDA approvals of such products. Our ability to market and sell our products is dependent on our and our partners’ ability to obtain and maintain required registrations and approvals of applicable regulatory agencies. Failure by our partners or us to comply with applicable regulations could result in fines or the withdrawal of approval for us or our partners and distributors to market our products in some or all jurisdictions or for certain indications, which could cause us to be unable to successfully commercialize SDC or otherwise achieve revenues from sales of such products.

We are subject to substantial regulation related to quality standards applicable to our manufacturing and quality processes, and our partners, includ ing our third-party manufacture.   F ailure to comply with applicable quality standards could affect our ability to commercialize SDC products.

The EPA and other applicable U.S. and foreign government agencies regulate our and our partners’ systems and processes, including those of ICC, for manufacturing SDC-based products. These regulations require that we and our partners observe “good manufacturing practices” in order to ensure product quality, safety and effectiveness. Failure by us or our partners to comply with current or future government regulations and quality assurance guidelines could lead to temporary manufacturing shutdowns, product recalls or related field actions, product shortages, and/or delays in product manufacturing, any or all of which could cause significant cost to us. Further, efficacy or safety concerns and/or manufacturing quality issues with respect to our products or those of our partners could lead to product recalls, fines, withdrawal of approvals, and/or declining sales, any or all of which could result in our failure to successfully commercialize SDC or otherwise achieve revenue growth.

Pricing and supply issues may have a material impact on our margins and our ability to supply our customers.

All of the supply ingredients used to manufacture our products are available from multiple suppliers. However, commodity prices for some ingredients can vary significantly and the margins that we are able to generate could decline if prices rise. For example, both silver and citric acid prices have been volatile in recent periods.

In addition to such commodities, for finished products we also rely on producers of specialized packaging inputs such as bottles and labels. Due to their specialized nature, the supply of such inputs can be periodically constrained and result in additional costs to obtain these items, which may in turn inhibit our ability to supply products to our customers.

We are generally unable to increase our product prices to our customers, partners and distributors quickly in order to maintain our margins, and significant price increases for key inputs could therefore have an adverse effect on our results of operations. Price increases can also result in lost sales, and any inability to supply our customers’ orders can lead to lost future sales to such customers.

We expect ICC to be the sole source supplier of our SDC concentrate and we may use other third parties to blend, package and provide fulfillment activities for our finished products in future periods. We expect that our margins may be reduced by using ICC and other such third parties, and our ability to maintain product quality may not be as extensive or effective as when we produce these products in our own facility(ies). Any quality control issues could lead to product recalls and/or the loss of future sales, which would reduce our revenues and/or profits.

If we suffer negative publicity concerning the safety or efficacy of our products, our sales may be harmed.

If concerns should arise about the safety or efficacy of any of our products that are marketed, regardless of whether or not such concerns have a basis in generally accepted science or peer-reviewed scientific research, such concerns could adversely affect the market for those products. Similarly, negative publicity could result in an increased number of product liability claims, whether or not those claims are supported by applicable law.

Third parties may claim that we infringe their proprietary rights and may prevent us from manufacturing and selling some of our products.

Our manufacture, use and sale of SDC-based products may subject us to lawsuits relating to the validity and infringement of patents or other proprietary rights of third parties. Litigation may be costly and time-consuming, and could divert the attention of our management and technical personnel. If we are found to have violated the trademark, trade secret, copyright, patent or other intellectual property or proprietary rights of others, such a finding could result in the need to cease use of a trademark, trade secret, copyrighted work or patented invention in our business and our obligation to pay a substantial amount for past infringement. If the rights holders are willing to permit us to continue to use their intellectual property rights, it may be necessary for us to enter into license arrangements with unfavorable terms and pay substantial amounts in royalty and other license fees. Either having to cease use or pay such fees could prevent us, or our third-party manufacture, from manufacturing and selling our products, which could make us much less competitive in our industry and have a material adverse impact on our business, operating results and financial condition.

We may become subject to product liability claims.

As a business that manufactures and markets products for use by consumers and institutions, we may become liable for any damage caused by our products, whether used in the manner intended or not. Regardless of merit or potential outcome, product liability claims against us may result in, among other effects, the inability to commercialize our products, impairment of our business reputation, and distraction of management’s attention from our primary business. If we cannot successfully defend ourselves against product liability claims we could incur substantial liabilities. Although we maintain general and product liability insurance, our insurance may not cover potential claims and may not be adequate to indemnify for liabilities that may be imposed. Any imposition of liability that is not covered by insurance or is in excess of insurance coverage could harm our business and operating results.

Litigation or the actions of regulatory authorities may harm our business or otherwise distract our management.

Substantial, complex or extended litigation could cause us to incur major expenditures and would distract our management. For example, lawsuits against us or our officers or directors by employees, former employees, stockholders, partners, customers, or others, or actions taken by regulatory authorities, could be very costly and substantially disrupt our business. Such lawsuits and actions are not uncommon, and we may not be able to resolve such disputes or actions on terms favorable to us, and there may not be sufficient capital resources available to defend such actions effectively, or at all.

Maintaining compliance with our obligations as a public company may strain our resources and distract management, and if we do not remain compliant , our stock price may be adversely affected.

Our common stock is registered under the Securities and Exchange Act of 1934, as amended (the “Exchange Act”). It is therefore subject to the information, proxy solicitation, insider trading and other restrictions and requirements of the SEC under the Exchange Act. Both the U.S. Congress and the SEC continue to issue new and proposed rules, and complying with existing and new rules has caused, and will continue to cause, us to devote significant financial and other resources to maintain our status as a public company. These regulatory costs and requirements will continue to increase our losses in future periods, and we expect that an increasing amount of management time and effort will be needed to meet our regulatory obligations. In addition, if we were to list our common stock on a national securities exchange, our administrative costs could increase.  For example, in April 2008 , we obtained a listing of our common stock on The NASDAQ Capital Market. Administrative costs significantly increased during the period between September 2011 and September 2012 due to a series of notices and a lengthy appeal process in connection with the potential delisting of our common stock from The NASDAQ Capital Market. However, NASDAQ delisted us and suspended trading in our securities effective with the open of business on Friday, May 17, 2013 , and our common stock began trading on the OTCQB marketplace.

Section 404 of the Sarbanes-Oxley Act of 2002 requires that we evaluate our internal control systems and that management report on and attest to the adequacy of our internal controls. Recent SEC pronouncements suggest that in the next several years we may be required to report our financial results using new International Financial Reporting Standards, replacing GAAP, which would require us to make significant investments in training, hiring, consulting and information technology, among other investments. All of these and other reporting requirements and heightened corporate governance obligations that we face, or may face in the future, will further increase the cost to us, perhaps substantially, of remaining compliant with our obligations under the Exchange Act and other applicable laws, including the Sarbanes-Oxley Act and the Dodd-Frank Act of 2010. In order to meet these incremental obligations, we will need to invest in our corporate and accounting infrastructure and systems, and acquire additional services from third party auditors and advisors. As a result of these requirements and investments, we may incur significant additional expenses and may suffer a significant diversion of management’s time. There is no guarantee that we will be able to continue to meet these obligations in a timely manner. If we fail to do so, we could be subject to sanctions or investigation by regulatory authorities such as the SEC. Any such actions could adversely affect the market price of our common stock, perhaps significantly.

Our publicly filed reports are reviewed from time to time by the SEC, and any significant changes or amendments required as a result of any such review may result in material liability to us and may have a material adverse impact on the trading price of our common stock.

The reports and other securities filings of publicly traded companies are subject to review by the SEC from time to time for the purpose of assisting companies in complying with applicable disclosure requirements. The SEC is required, pursuant to the Sarbanes-Oxley Act of 2002, to undertake a comprehensive review of a company’s reports at least once every three years, although an SEC review may be initiated at any time. While we believe that our previously filed SEC reports comply, and we intend that all future reports will comply, in all material respects with the published rules and regulations of the SEC, we could be required to modify, amend or reformulate information contained in our filings as a result of any SEC review. Any modification, amendment or reformulation of information contained in such reports could be significant and result in material liability to us and have a material adverse impact on the trading price of our common stock.

We depend on key personnel for our continued operations and future success, and a loss of certain key personnel could significantly hinder our ability to move forward with our business plan.

Our success depends largely on the execution of our business strategy by our management team. Management will be evaluating how to best execute our near-term strategy to drive customer adoption in the food industry by addressing food safety solutions across the supply chain in order to prevent or mitigate food contamination or the potential for food-borne illness – with specific customer focus in foodservice providers, food processors and food manufacturers.  Our executive officers and key personnel could terminate their employment with us at any time without notice and without penalty.  For example, effective July 31, 2015, Peter C. Wulff resigned as our Chief Financial Officer, Chief Operating Officer, and Corporate Secretary. Additionally, we do not maintain key person life insurance policies on our executive officers or other employees. The loss of one or more of our executive officers or key employees could seriously harm our ability to execute on our business strategy, which could harm our business, results of operations, financial condition, and/or the market price of our common stock. We cannot assure you that in such an event we would be able to recruit qualified personnel able to replace these individuals in a timely manner, or at all, on terms acceptable to either us or to any qualified candidate.  Even if we were able to replace any such individuals in a timely manner, if we are unable to effectively integrate new executive offices or key employees, our operations and prospects could be harmed.

Because competition for highly qualified business development and bioengineering personnel is intense, we may not be able to attract and retain the employees we need to support our potential growth.

To successfully meet our objectives, we must attract and retain highly qualified business development and bioengineering personnel with specialized skill sets focused on the industries in which we compete, or intend to compete. Competition for qualified business development and bioengineering personnel can be intense. Our ability to meet our business development objectives will depend in part on our ability to recruit, train and retain top quality people with advanced skills who understand our technology and business. In addition, it takes time for our new personnel to become productive and to learn our business. If we are unable to hire or retain qualified business development and bioengineering personnel, it will be difficult for us to sell our products or to license our technology or to achieve or maintain regulatory approvals, and we may experience a shortfall in revenue and not achieve our anticipated, or any, growth.

We may engage in strategic transactions that could impact our liquidity, increase our expenses and present significant distractions to our management.

From time to time we may consider engaging in strategic transactions, such as acquisitions of companies, asset purchases and out-licensing or in-licensing of products, product candidates or technologies. Any such transaction may require us to incur non-recurring or other charges, may increase our near and long-term expenditures and may pose significant integration challenges or disrupt our management or business, which could adversely affect our operations and financial results. For example, these transactions may entail numerous operational and financial risks, including, among others, exposure to unknown liabilities, disruption of our business and diversion of our management’s time and attention in order to develop acquired products, product candidates or technologies, difficulty and cost in combining the operations and personnel of any acquired businesses with our operations and personnel, and inability to retain key employees of any acquired businesses. Accordingly, although we may not choose to undertake or may not be able to successfully complete any transactions of the nature described above, any transactions that we do undertake or complete could have a material adverse effect on our business, results of operations, financial condition and prospects.

We may invest or spend our cash in ways with which you may not agree or in ways which may not yield a significant return.

Our management has considerable discretion in the use of our cash. Our cash may be used for purposes that do not increase our operating results or market value. Until the cash is used, it may be placed in investments that do not produce significant income or that may lose value. The failure of our management to invest or spend our cash effectively could result in unfavorable returns and uncertainty about our prospects, each of which could cause the price of our common stock to decline.

We may not be able to utilize all, or any, of our tax net operating loss carry-forwards and our future after-tax earnings, if any, could be reduced.

At July 31, 201 5 , we had federal and California tax net operating loss carry-forwards of approximately $ 89.8 million and $77.1 million, respectively. Utilization of these net operating loss carry-forwards may be subject to a substantial annual limitation due to ownership change limitations that may have occurred, including with respect to our recent private placements, or that could occur in the future, as required by Section 382 of the Internal Revenue Code as well as similar state provisions. These ownership changes may limit the amount of net operating loss carry-forwards that can be utilized annually to offset future taxable income and tax, respectively. In general, an ownership change, as defined by Section 382 of the Internal Revenue Code, results from a transaction or series of transactions over a three-year period resulting in an ownership change of more than 50 percentage points of the outstanding stock of a company by certain stockholders or public groups. Since our formation, we have raised capital through the issuance of capital stock on several occasions (both before and after our initial public offering in 1996) which, combined with the purchasing stockholders’ subsequent disposition of those shares, may have resulted in such an ownership change, or could result in an ownership change in the future based upon subsequent disposition. While we believe that we have not experienced an ownership change, the pertinent tax rules related thereto are complex and subject to varying interpretations, and thus the applicable taxing authorities may take an alternative position.

Our current federal tax loss carry-forwards began expiring in the year ended July 31, 2011 and, unless previously utilized, will completely expire in the year ending July 31, 203 5 . The balance of our current federal net operating loss carry-forwards will expire between July 31, 2019 and July 31, 2035 . Our California tax loss carry-forwards will begin to expire in the year ending July 31, 2015, and will completely expire in the year ending July 31, 203 5 . If we are unable to earn sufficient profits to utilize the carry-forwards by these dates, they will no longer be available to offset future profits, if any.

We are subject to tax audits by various tax authorities in multiple jurisdictions.

From time to time we may be audited by tax authorities to whom we are subject. Any assessment resulting from such audits, if any, could result in material changes to our past or future taxable income, tax payable or deferred tax assets, and could require us to pay penalties and interest that could materially adversely affect our financial results.

Risks Related to Our Intellectual Property

If we are unable to obtain, maintain or defend the patent and other intellectual property rights relating to our technology, we or our collaborators and distributors may not be able to develop and market proprietary products based on our technology, which would have a material adverse impact on our results of operations.

We rely and expect in the future to continue to rely on a combination of patent, trademark, trade secret and copyright protections, as well as contractual restrictions, to protect the proprietary aspects of our technology and business.

Legal protections of our intellectual property and proprietary rights afford only limited protection. For instance, we currently own twelve U.S. patents related to our SDC technology. The lives of these patents, and any patents that we may obtain in the future, are not indefinite, and the value to us of some or all of our patents may be limited by their terms. Further, although we have a number of U.S. and international patent applications pending, some or all of those applications may not result in issued patents, and the intellectual property claims therein would be unprotected. Additionally, obtaining and maintaining patent protection depends on our compliance with various procedural, document submission, fee payment and other requirements imposed by government patent agencies, and our patent protection could be reduced or eliminated for non-compliance with these requirements. Furthermore, the patent positions of bioscience companies can be highly uncertain and often involve complex legal, scientific and factual questions, and, therefore, we cannot predict with certainty whether we will be able to ultimately enforce our patents or other intellectual property rights. Third parties may challenge, invalidate or circumvent our patents and patent applications relating to our products, product candidates and technologies. In addition, our patent positions might not protect us against competitors with similar products or technologies because competing products or technologies may not infringe our patents.

From time to time, U.S. and other policymakers have proposed reforming the patent laws and regulations of their countries. In September 2011, after years of Congressional debate regarding patent reform legislation, President Obama signed into law the America Invents Act (the “ Act ” ) considered by many to be the most substantial revision of U.S. patent law since 1952. The Act’s various provisions will go into effect over an 18-month period. The Act changes the current “first-to-invent” system to a system that awards a patent to the “first-inventor-to-file” for an application for a patentable invention. This change alters the pool of available materials that can be used to challenge patents and eliminates the ability to rely on prior research work in order to lay claim to patent rights. Disputes as to whether the first filer is in fact the true inventor will be resolved through newly implemented derivation proceedings. The Act also creates mechanisms to allow challenges to newly issued patents in the patent office in post-grant proceedings and new inter partes reexamination proceedings. Although many of the changes bring U.S. law into closer harmony with European and other national patent laws, the new bases and procedures may make it easier for competitors to challenge our patents, which could result in increased competition and have a material adverse effect on our product sales, business and results of operations. The changes may also make it harder to challenge third-party patents and place greater importance on being the first inventor to file a patent application on an invention.

In addition, to the extent that we operate internationally, the laws of foreign countries may not protect our proprietary rights to the same extent as the laws of the U.S. Many countries have a “first-to-file” trademark registration system, which may prevent us from registering or using our trademarks in certain countries if third parties have previously filed applications to register or have registered the same or similar trademarks. Additionally, changes in the patent and/or trademark laws or interpretations of such laws in the U.S. or other countries could diminish the value of our intellectual property rights. Moreover, our competitors may develop competing technologies that are not covered by the claims of, and therefore do not infringe upon, our issued patents, which could render our patents less valuable to us. If certain of our proprietary rights cannot be, or are not sufficiently, protected by patent and trademark registrations, it could have a material adverse impact on our business and our ability to commercialize or license our technology and products.

Our own efforts to protect our intellectual property and other proprietary rights may also be insufficient. Despite efforts to protect our proprietary rights, including without limitation through confidentiality and other similar contractual restrictions, our means of protecting such rights may not be adequate and unauthorized parties may attempt to copy aspects of our proprietary technology, obtain and use information that we regard as proprietary, or otherwise misappropriate our intellectual property. In addition, unpatented proprietary rights, including trade secrets and know-how, can be difficult to protect and may lose their value if they are independently developed by a third party or if their secrecy is lost. It is possible that, despite our efforts, competitors or others will create and use products, adopt service names similar to our service names or otherwise violate or misappropriate our proprietary rights. The infringement of such rights could have a material negative impact on our business and on our results of operations.

Litigation may be necessary to enforce our intellectual property and other proprietary rights, which would be expensive and could consume time and other resources. The result of any such litigation may be the court’s ruling that our patents or other intellectual property rights are invalid and/or should not be enforced. Additionally, even if the validity of such rights is upheld, the court could refuse to stop a third party’s infringing activity on the ground that such activities do not infringe our rights. The U.S. Supreme Court has recently revised certain tests regarding granting patents and assessing the validity of patents to make it more difficult to obtain patents. As a consequence, issued patents may be found to contain invalid claims according to the newly revised standards. Some of our patents may be subject to challenge and subsequent invalidation or significant narrowing of claim scope in a reexamination proceeding, or during litigation, under the revised criteria.

We may incur substantial costs as a result of litigation or other proceedings relating to patent and other intellectual property rights and we may be unable to protect our rights to, or use, our technology.

If we choose to go to court to stop someone else from using the inventions claimed in our patents, that individual or company has the right to ask the court to rule that these patents are invalid and/or should not be enforced against that third party. These lawsuits are expensive and would consume time and other resources even if we were successful in stopping the infringement of these patents. In addition, there is a risk that the court will decide that these patents are not valid and that we do not have the right to stop the other party from using the inventions. There is also the risk that, even if the validity of these patents is upheld, the court will refuse to stop the other party on the ground that such other party’s activities do not infringe our rights to these patents.

Furthermore, a third party may claim that we are using inventions covered by the third party’s patent rights and may file an injunction to stop us from engaging in our normal operations and activities, including making or selling our products. These lawsuits are costly and could affect our results of operations and divert the attention of managerial and technical personnel. There is a risk that a court would decide that we are infringing the third party’s patents and would order us to stop the activities covered by the patents. In addition, there is a risk that a court will order us to pay the other party damages for having violated the other party’s patents. The biotechnology industry has produced a proliferation of patents, and it is not always clear to industry participants, including us, which patents cover various types of products or methods of use. The coverage of patents is subject to interpretation by the courts, and the interpretation is not always uniform. If we are sued for patent infringement, we would need to demonstrate that our products or methods of use either do not infringe the patent claims of the relevant patent and/or that the patent claims are invalid, and we may not be able to do this. Proving invalidity, in particular, is difficult since it requires a showing of clear and convincing evidence to overcome the presumption of validity enjoyed by issued patents.

Because some patent applications in the United States may be maintained in secrecy until the patents are issued, patent applications in the United States and many foreign jurisdictions are typically not published until eighteen months after filing, and publications in the scientific literature often lag behind actual discoveries, we cannot be certain that others have not filed patent applications for technology covered by our issued patents or our pending applications or that we were the first to invent the technology. Our competitors may have filed, and may in the future file, patent applications covering technology similar to ours. Any such patent application may have priority over our patent applications and could further require us to obtain rights to issued patents covering such technologies. If another party has filed a United States patent application on inventions similar to ours, we may have to participate in an interference proceeding declared by the PTO, to determine priority of invention in the United States. The costs of these proceedings could be substantial, and it is possible that such efforts would be unsuccessful, resulting in a loss of our United States patent position with respect to such inventions.

Some of our competitors may be able to sustain the costs of complex patent litigation more effectively than we can because they have substantially greater resources. In addition, any uncertainties resulting from the initiation and continuation of any litigation could have a material adverse effect on our ability to raise the funds necessary to continue our operations.

Confidentiality agreements with employees and others may not adequately prevent disclosure of our trade secrets and other proprietary information and may not adequately protect our intellectual property, which could limit our ability to compete.

We may rely in part on trade secret protection in order to protect our proprietary trade secrets and unpatented know-how. However, trade secrets are difficult to protect, and we cannot be certain that others will not develop the same or similar technologies on their own. We have taken steps, including entering into confidentiality agreements with our employees, consultants, outside scientific collaborators, sponsored researchers and other advisors, to protect our trade secrets and unpatented know-how. These agreements generally require that the other party keep confidential and not disclose to third parties all confidential information developed by the party or made known to the party by us during the course of the party’s relationship with us. We also typically obtain agreements from these parties which provide that inventions conceived by the party in the course of rendering services to us will be our exclusive property. However, these agreements may not be honored and may not effectively assign intellectual property rights to us. Enforcing a claim that a party illegally obtained and is using our trade secrets or know-how is difficult, expensive and time consuming, and the outcome is unpredictable. In addition, courts outside the United States may be less willing to protect trade secrets or know-how. The failure to obtain or maintain trade secret protection could adversely affect our competitive position.

We may be subject to claims that our employees have wrongfully used or disclosed alleged trade secrets of their former employers.

As is common in the biotechnology, food, chemical and pharmaceutical industries, we employ individuals who were previously employed at other biotechnology, food, chemical or pharmaceutical companies, including our competitors or potential competitors. Although no claims against us are currently pending, we may be subject to claims that these employees or we have inadvertently or otherwise used or disclosed trade secrets or other proprietary information of their

former employers. Litigation may be necessary to defend against these claims. Even if we are successful in defending against these claims, litigation could result in substantial costs and be a distraction to management.

Risks Related to our Common Stock

The price of our common stock may be volatile .  

Our common stock is approved for quotation on the OTC Markets’ OTCQB marketplace under the symbol “PURE.” The OTCQB is a regulated quotation service that displays real-time quotes, last-sale prices and volume information in over-the-counter equity securities and provides significantly less liquidity than a listing on the Nasdaq Stock Markets or other national securities exchange. The OTCQB securities are traded by a community of market makers that enter quotes and trade reports. This market is limited in comparison to the national stock exchanges and any prices quoted may not be a reliable indication of the value of our common stock.  Quotes for stocks included on the OTCBB are not listed in the financial sections of newspapers as are those for the Nasdaq Stock Market or the NYSE. Therefore, prices for securities traded solely on the OTCBB may be difficult to obtain.

Trading on the OTCQB Marketplace as opposed to a national securities exchange has resulted and may continue to result in a reduction in some or all of the following, each of which could have a material adverse effect on the price of our common stock and our company:

In addition, the market price of our common stock could be subject to wide fluctuations in response to:

Our common stock is deemed to be “penny stock,” which may make it more difficult for investors to sell their shares due to suitability requirements.

Shares of our common stock are subject to the so-called “penny stock” rules as that term is defined in Rule 3a51-1 promulgated under the Securities Exchange Act of 1934. These requirements may reduce the potential market for our common stock by reducing the number of potential investors. This may make it more difficult for investors in our common stock to sell shares to third parties or to otherwise dispose of them. This could cause our stock price to decline.

Broker-dealers dealing in penny stocks are required to provide potential investors with a document disclosing the risks of penny stock. Moreover, broker-dealers are required to determine whether an investment in a penny stock is a suitable investment for a prospective investor. Such requirements may discourage broker-dealers from effecting transactions in our common stock, which could limit the market price and liquidity of our common stock.

The price of our common stock may be volatile, which may cause investment losses for our stockholders.

The price and trading volume of our common stock have historically been volatile. For example, in the twelve months through July 31, 201 5 , the closing market price of our common stock ranged from $0. 45 per share to $1. 18 per share, and the monthly trading volume varied from approximately 395,000 shares to 2,195,000 shares. The market price of our common stock may continue to be volatile and could fluctuate substantially due to many factors, including, among others, the following:

In addition, the stock market in general, the OTCQB, and the market for shares of novel technology and biotechnology companies in particular, have experienced extreme price and volume fluctuations that in some cases may be unrelated or disproportionate to the operating performance of those companies. Further, the market prices of bioscience companies’ stock have been unusually volatile in recent periods, and such volatility may continue for the foreseeable future. These broad market and industry factors may materially harm the market price of our common stock, regardless of our operating performance. In addition, this volatility could adversely affect an investor’s ability to sell shares of our common stock, and/or the available price for such shares, at any given time.

Following periods of volatility in the market price of a company’s securities, stockholder derivative lawsuits and securities class action litigation are common. Such litigation, if instituted against us or our officers and directors, could result in substantial costs and a diversion of management’s attention and resources.

Potentia l   sales or issuances of our common stock to raise capital, or the perception that such sales could occur, could cause dilution to our current stockholders and the price of our common stock to fall.

We have historically supported our operations through the issuance of equity and expect to continue to do so in the futu re. For example, on October 23 , 2015, we closed on a private placement of 13,333,333 shares of common stock and warrants to purchase 15,333,333 shares of common stock for ag gregate gross proceeds of $6,000,000 . Although we may not be successful in obtaining financing through equity sales on terms that are favorable to us in the future, if at all, any such sales that do occur could result in substantial dilution to the interests of existing holders of our common stock. Additionally, the sale of a substantial number of shares of our common stock or other equity securities to any new investors, or the anticipation of such sales, could cause the trading price of our common stock to fall.  

We have never paid dividends on our capital stock, and we do not anticipate paying any cash dividends in the foreseeable future.

The continued operation and expansion of our business will require substantial funding. Investors seeking cash dividends in the foreseeable future should not purchase our common stock. We have paid no cash dividends on any of our capital stock to date and we currently intend to retain our available cash to fund the development and growth of our business. Any determination to pay dividends in the future will be at the discretion of our Board and will depend upon results of operations, financial condition, contractual restrictions, restrictions imposed by applicable law and other factors our Board deems relevant. We do not anticipate paying any cash dividends on our common stock in the foreseeable future. Any return to stockholders will therefore be limited to the appreciation of their stock, which may never occur.

Anti-takeover provisions under our charter documents and Delaware law could delay or prevent a change of control and could also limit the market price of our stock.

Certain provisions of our charter and bylaws may delay or frustrate the removal of incumbent directors and may prevent or delay a merger, tender offer, or proxy contest involving us that is not approved by our Board, even if such events may be beneficial to the interests of stockholders. For example, our Board, without stockholder approval, has the authority and power to authorize the issuance of up to 5,000,000 shares of preferred stock and such preferred stock could have voting or conversion rights that could adversely affect the voting power of the holders of our common stock. Further, the one-for-eight reverse stock split of our outstanding common stock that we effected on August 14, 2012 has increased the proportion of unissued and authorized common shares to issued and outstanding common shares, which could allow our Board to issue large numbers of additional shares of our common stock that could significantly reduce the voting power of our current stockholders. In addition, we are governed by the provisions of Section 203 of the Delaware General Corporation Law, which may discourage, delay or prevent certain business combinations with stockholders owning 15% or more of our outstanding voting stock. These and other provisions in our charter documents may make it more difficult for stockholders or potential acquirers to initiate actions that are opposed by our then-current board of directors, including delaying or impeding a merger, tender offer, or proxy contest or other change of control transaction involving the Company. Any delay or prevention of a change of control transaction could cause stockholders to lose a substantial premium over the then-current market price of their shares.