Before they can be put on the market, pesticides are usually tested for safety on animals. Government regulators then establish an exposure level for humans that is 10 times more conservative than the safety level for animals. In an effort to abolish the tenfold safety net, pesticide companies frequently sponsor clinical tests on volunteers to try to prove that their products are as safe for humans as for animals. In December 2001, the U.S. EPA imposed a moratorium on using data from such tests until the ethical and scientific acceptability of human clinical trials could be determined. Pesticide companies sued over the moratorium, and yesterday, a federal appeals court ruled in their favor, saying the agency must take the findings from human trials into account when establishing safety levels. Environmentalists criticized the court’s decision, saying it amounted to an endorsement of exposing people to toxic chemicals to benefit the pesticide industry’s bottom line.