ZENON:  CANADA'S TOP CORPORATE CITIZEN

Independent survey of Canada's largest companies rates ZENON as the number one corporate citizen in the country

OAKVILLE, Ontario, May 30, 2002 - ZENON Environmental (TSE:  ZEN and ZEN.A), was chosen as Canada's top Corporate Citizen by Corporate Knights, a business publication that addresses corporate social responsibility.

Michael Jantzi Research Associates Inc. was hired by Corporate Knights to independently score the ranking of Canada's 300 largest publicly listed
companies, using a six step scoring system.  The categories scored include
community, employee relations/diversity, environment, product safety and
business practices, international, and profitability.

"We are extremely proud to be the recipient of this honourable distinction,"
said Andrew Benedek, Chairman and Chief Executive Officer of ZENON.  "There are many excellent corporate citizens in Canada and the challenge now will be to maintain ZENON's position in future years."

According to Corporate Knights creators Toby Heaps and Paul Fengler, their ranking found that the share performance of the most socially responsible companies outperformed that of the general market.  The compound 5-year return of the Best 50 Corporate Citizens to December 31, 2001 was 21.9, compared to the average Canadian equity mutual fund performance of 6.7 for the same period.

Business Ethics, the U.S. version of Canada's Corporate Knights, has been
conducting a similar ranking of U.S. companies since 1996 where IBM has been in the number one position in two of the last three years.

ZENON is a world leader in providing advanced membrane products and services for water purification, wastewater treatment and water reuse.

Chosen as one of Canada's Top 100 Employers for the second consecutive year, the ZENON group of companies operates from seven locations in North America, six in Europe, and one in each of Asia, Latin America, and the Middle East.

ZENON's products and services are marketed for a variety of municipal and industrial applications through ZENON's offices and representatives located throughout the world.  

Additional information is available at the Company's web site
www.zenonenv.com.