U.S. regulators have announced plans to reduce the number of animals used to test the safety of everyday chemicals. Instead of using animals such as rats and mice, scientists will screen suspected toxic chemicals in everything from pesticides to household cleaners using cell cultures and computer models. Safety of chemicals More than 3.1 million experiments in the U.K. were carried out on animals in 2006. Of these more than 420,000 were done to test the safety of chemicals. According to the animal rights group People for the Ethical Treatment of Animals (Peta), more than 100 million animals are used annually in experiments in the U.S., of which 15 million are used in toxicity tests. The plans to replace animals in the U.S., announced recently in Boston, will see researchers from the national institute of health and the environmental protection agency develop robotic machines to screen the chemicals. Implications They said if successful the robots could test a greater number of chemicals more quickly. This could have implications for the EU's Reach legislation, which requires retesting all synthetic chemicals used in member countries. Critics are worried that the new rules will increase the number of animals used. The screening machines will be inspired by those developed for medical research, which can quickly test thousands of different molecules in a few days to see if any have potential as useful drugs. Chemical genomics "We now are seeing tools newly available to us for chemical genomics research deployed for greater refinement, speed and capacity in chemical toxicity screening,' said Francis Collins, director of the national human genome research institute and author of a paper published recently in Science. Describing the proposed techniques, Catherine Willett, science policy adviser at Peta, said: "This is a significant change in the perspective of U.S. agencies, which have historically relied heavily on animal testing out of habit and have been resistant to change.'