On December 14, 2001, the U.S. Environmental Protection Agency (EPA) issued a press release establishing an "interim" human testing policy for pesticides that suspended EPA's long-established policy of using human testing data to establish pesticide tolerances or to determine other human health-protective limits on chemical exposures. The policy was restricted to the results of studies using human subjects sponsored by private companies (so-called third-party studies). That press release signaled a departure from previous EPA policy on human testing as indicated by two 1998 statements issued by the EPA Office of Prevention, Pesticides, and Toxic Substances, one of which states that the protection of public health from adverse effects of pesticides can be achieved through reliance on animal testing and the use of the highest ethical standards. The other is an internal memorandum indicating that EPA will not consider a human study unless it meets the highest ethical standards (without specifying what those standards should be). Prior EPA policies and guidance for the protection of public health encouraged the use of human data, giving such data priority over all other types of toxicity testing data, without addressing specifically the issue of ethical conduct. For example, EPA's guidelines for developmental toxicity risk assessment state: "Human data are preferred for risk assessment." Between January and October 1998, EPA itself conducted or supported 43 research projects involving human subjects and chemical exposures.

EPA's policy suspending consideration of data from third-party studies using human subjects resulted from several concerns. One concern is that using human data as the basis for pesticide tolerances would lead to less stringent tolerances, placing public health at risk. Another concern is that using human data is inconsistent with the protection of children's health through the additional safety factor required for tolerance-setting by the Food Quality Protection Act (FQPA). A third concern is that clinical studies conducted by contract laboratories on behalf of pesticide manufacturers (or other private companies) do not adhere to the ethical standards for the protection of human subjects that were established by the Federal Policy for the Protection of Human Subjects, generally known as the Common Rule. A final concern is that intentionally exposing human subjects to chemicals is unethical, even if the goal of doing so is public health protection.