EVALUATION OF REDUCED PROTOCOLS FOR CARCINOGENICITY TESTING OF CHEMICALS - REPORT OF A JOINT EPA NIEHS WORKSHOP/

The current U.S. Environmental Protection Agency (EPA) and other natio nal/international guidelines specify the use of two species and two se xes of rodents (usually the rat and the mouse) for carcinogenicity tes ting of chemicals. In view of the enormous number of chemicals to be t ested, the high cost of testing, and the large number of animals used in the present protocol, many academic, industrial, and government aut horities are examining the possibility of using a reduced protocol (le ss than two species and two sexes of rodents) for carcinogenicity test ing of chemicals. The use of a reduced protocol offers many advantages as well as some disadvantages. To pursue further the potential implic ations and impacts of using a reduced protocol for carcinogenicity tes ting on the processes of hazard identification and risk assessment, a workshop entitled ''Evaluation of Reduced Protocols for Carcinogenicit y Testing of Chemicals'' was held at the Embassy Suites Hotel in Alexa ndria, Virginia on September 22 and 23, 1992. It was cosponsored by EP A's Office of Prevention, Pesticides and Toxic Substances (OPPTS) and the National Toxicology Program of the National Institutes of Environm ental Health Sciences (NTP/NIEHS) and attended by more than 60 partici pants from government, industry, academia, and the general public. The Expert Consensus Panel and most of the participants supported the use of reduced protocols in carcinogenicity testing. However, it was reco gnized that reduced protocols may not be appropriate for the testing o f all chemicals and that additional analyses/data may be needed for se lection of the most appropriate reduced protocol for certain chemicals /chemical classes. (C) 1994 Academic Press, Inc.