The U.S. EPA has decided to adopt a policy of ignoring experiments conducted on humans by pesticide companies when setting legal limits for the chemicals in food and water, officials said yesterday. The agency does not regulate scientific research by private companies, but it has usually relied on industry studies to establish limits for pesticides. Most limits in the past have been based on experiments on lab animals and on humans who weren’t deliberately exposed to chemicals, such as farm workers. But industry groups have recently been advocating more human studies, contending that regulations stemming from animal research are often too strict. Many scientists, medical ethicists, and environmentalists have expressed outrage at the idea of any pesticide testing on humans.