TSO3 re-evaluates protocol for the current phase of testing on prions
TSX Stock Symbol: TOS
Outstanding Shares: 31,400,295

QUEBEC CITY, Aug. 12 /CNW Telbec/ - Before the planned end of the third phase of testing on prions underway at the National Research Council of Canada
(NRC) facilities in Winnipeg, TSO3 has not obtained the results anticipated.
The partial deactivation of prions has generated symptoms of the disease in certain subjects inoculated with substances extracted from plaques sterilized with ozone. This partial deactivation is not concordant with the results obtained in previous studies where ozone showed a capacity to deactivate prions superior to the level observed during the current phase of testing.
"These partial results are disappointing, however the recognized oxidizing power of ozone, as well as the results of our previous studies, moves us to re-evaluate our current protocols and to maintain our research program. We still believe in the superior capacity of ozone to deactivate prions," emphasized Simon Robitaille, Vice President, Operations, and Director of Research at TSO3.
After the start of this third phase of TSO3's program and again only recently, new scientific publications utilizing a different methodology impelled TSO3 to re-evaluate the Company's protocols so that its results can be compared to those obtained through the other sterilization technologies.
The measuring technique for residual infectious capability utilized in the recent studies in question has the advantage of corresponding more closely to the usual practice in hospitals.
The current testing consists of taking the brains from sick mice and making a homogenate that is spread on plaques and left to dry, then sterilized in the ozone sterilizer, while other samples are sterilized with steam, in order to compare the effectiveness of ozone to the autoclave. The residual matter is then recovered and injected into the brains of mice. This phase was planned to take six months, scheduled to conclude at the end of October 2004.
TSO3 intends to initiate a new phase of testing, with new protocols, at the end of 2004.
"As far as our commercialization strategy is concerned, the business plan for the 125L Ozone Sterilizer is based on the benefits of our technology, such as its efficiency, its rapidity and cost advantages. This news in no wise affects TSO3's business plan. Nor will it impact the commercial launch of the 125L or its expected market penetration," added Jocelyn Vézina, the Chief Executive Officer at TSO3.

About TSO3

TSO3 Inc. is located in Québec City, Québec, Canada, and was founded in 1998. TSO3 currently has 45 employees, 17 of whom work exclusively in the Research and Development department. The company's mission is to develop and market innovative and comprehensive sterilization solutions.
TSO3 has perfected a novel sterilization process using ozone as a sterilizing agent. The first product based on this technological platform is the 125L Ozone Sterilizer, which is intended for hospital sterilization units. The 125L - named after its 125-litre/4.3-cubic-foot capacity - was designed to sterilize the new generation of surgical and diagnostic instruments made of non-heat-resistant materials such as polymers and other plastics. The ozone sterilization process is a safe, efficient, fast and cost-effective response to evolving sterilization needs.
The 125L Ozone Sterilizer by TSO3 was cleared for commercialization by Health Canada in May 2002 and the U.S. Food and Drug Administration (FDA) on September 3, 2003.
The Company's R&D team has also undertaken the development of a smaller, point-of-use ozone sterilization device for operating rooms and private clinics, and is planning the development of an industrial-sized device for
manufacturers of medical instruments, among others.

For more information on TSO3, visit the Company's Web site at www.tso3.com .

The statements in this release and oral statements made by representatives of TSO3 relating to matters that are not historical facts(including, without limitation, those regarding the timing or outcome of any financing undertaken by TSO3,are forward-looking statements that involve certain risks, uncertainties and hypotheses, including, but not limited to, general business and economic conditions, the condition of the financial markets, the ability of TSO3 to obtain financing on favourable terms and other risks and uncertainties.

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