The principles and procedures for the assessment of the safety/risk of chemical used by the relevant WHO and EPA expert groups are outlined. The assessment in terms of acceptable daily intakes (ADIs) and reference doses (RfDs) of 25 pesticides is listed. The pesticides assessed are acephate, alachlor, amitrole, azinphos-methyl, benomyl, biphenthrin, bromophos, chlordane, chlorthalonil, cyhalothrin, DDT, EPTC, ethion, folpet, fosetyl-al, glyphosate, isofenphos, methomyl, methyl mercury, paraquat, phosphamidon, systhane, terbutyn, tribultyltin oxide, and vinclozin. In addition, their critical effects, the no-observed-effect levels and the size of the safety/uncertainty factors used are also listed to illustrate the diversity of the toxic effects and the resulting assessments. Furthermore, the enormous amount of data reviewed and the complex scientific judgement involved are also indicated. Considering the various uncertainties existing, the ADIs and RfDs do not differ appreciably in most instances. However, marked differences exist between the ADIs and RfDs of DDT and chlordane. It is suggested that re-evaluation be done on these, and perhaps other, chemicals.
