Does the Delaney Clause of the U.S. Food and Drug laws prevent human cancers?

The Delaney Clause of the Federal Food, Drug, and Cosmetic Act, enacted in 1958, prohibits the addition to the human food supply of any chemical that had caused cancer in humans or animals. The aim was to prevent cancer in humans. The scientific knowledge on causes of cancer and mechanisms of carcinogenesis in the 1950s can be rationalized to justify enactment of this Clause at that time. Since then, important progress in the fields of mechanism of carcinogenesis and cancer causation, and in analytical chemistry permitting accurate determination of trace amounts of chemicals, suggests that the Clause requires modification based on current knowledge. The documented human carcinogens are DNA reactive or genotoxic. Thus, the Clause should emphasize prohibition of the addition to human foods of proven genotoxins that are likely human cancer risks by contemporary standards. Such genotoxic carcinogens are those reliably positive in a battery of three tests, the Ames test in Salmonella typhimurium, the Williams test with evidence of DNA repair in hepatocytes, and direct documentation of DNA adduct formation in the 32P-postlabeling technique of Randerath.