Generation of Toxicological Data on Chemicals in the U.S.A.

Abstract

The paper reviews the current trends of toxicological testing of chemicals in the U.S.A. and the methods of data generation for risk assessment and regulatory purposes. The recent survey conducted by NAS/NRC revealed that only a small fraction of widely used chemicals have been tested toxicologically. In spite of developments in short-term toxicological tests, using non-mammalian test species continue to be indispensable.

In evaluating carcinogenicity tests, the current approach is generally based on the assumption that there is not threshold.

Under the regulation of the Toxic Substances Act 1977 (U.S.A.) the responsibility of providing toxicological data lies with the manufacturer. The National Toxicology Programme emerged as a new governmental agency for toxicological evaluation since 1978 integrating a number of pre-existing testing activities in U.S.A. A number of private testing laboratories which can provide test data on contract basis also have come into existence in U.S.A. The guidelines published for risk assessment by the Environmental Protection Agency is expected to provide standards for the conduct of toxicological tests used for regulatory purposes. The newly formed Board on Environmental Studies and Toxicology reviews and evaluates the toxicological issues.