An innovative initiative designed to make potentially environmentally beneficial technology patents freely available to anyone celebrated the addition of three new members yesterday, after Bosch, DuPont and Xerox announced they were to join the Eco-Patent Commons group.

Printing giant Xerox said it was to make available 11 patents designed to help cut the time it takes to remove toxic waste from soil and water. The patents all relate to a vacuum process designed to remove contaminated ground water and soil vapours from toxic areas, which the company claims has cut the time it takes to treat such areas by 80 per cent.

Patricia Calkins, Xerox vice president of environment, health and safety, said that the technology could prove a valuable tool for other businesses, " such as the local dry cleaners or gas stations, who need to clean up volatile organic compounds".

Meanwhile, chemical company DuPont said it would make four patents public domain, one of which helps use enzymes to break down certain plastics for use as fertilizer and three that relate to the detection of pollution in soil, air and water using patented microorganisms.

Engineering conglomerate completed the triumvirate with the donation of a number of automotive patents designed to lower fuel consumption through improved engine management.

The three companies were joined by Sony – a founder member of the Eco-Patent Commons group alongside IBM, Nokia and Pitney Bowes – which pledged three more patents relating to the recycling of optical discs.

Bjorn Stigson, president of the Worl d Business Council for Sustainable Development, which manages the group and makes the patents available on its web site, said that with many of the patent holders having been contacted by interested parties since the launch of the scheme in January and at least three patents having been used by others there were signs that the initiative was gaining momentum.

"We are pleased that the commons is beginning to have an impact," he said. " We hope it will be a positive contribution to the challenge of technology diffusion around the world."