A more scientific approach to the safety evaluation of chemicals

Abstract

The most extensive use of experimental animals is undoubtedly in the safety evaluation of drugs, food additives, pesticides, and other chemicals. Safety evaluation of a single drug or other chemical to the stage at which it can be marketed may involve the use of as many as 1,000 animals. The number of chemicals which have to be evaluated for safety each year is in excess of 1,000, so that in the United Kingdom alone several million experimental animals are likely to be used for the purposes of safety evaluation of chemicals. The extent of the problem is shown in table 1. Programmes of safety evaluation of chemicals involve a wide range of studies, from the LD50 test to three generation reproduction and carcinogenicity studies (see table 2). A variety of different animal species, from rodents to primates, may be used in these studies as models for man, in an attempt to evaluate the potential toxicity for the human consumer, but despite the recognition of major differences in the toxicology of chemicals between animals and man, safety evaluation is still largely empirical.