W. A. THOMASSON opens his article on saccharin and the Delaney Clause with a scenario in which he find him stumbling downstairs to brew a cup of coffee -- only to find that, thanks to Delaney and the FDA, he has no saccharin to put into it. Thomasson stumbles in more than one way in his scenario: Under the restrictions proposed by FDA, he would have been able to reach up onto the shelf for a bottle of saccharin to sweeten his brew. The ban FDA proposed would have applied only to the bulk use of saccharin in diet soft drinks and foods, not as a table sweetener. This introduction, though, does serve to establish the standard of accuracy that Thomasson plans to meet in the remainder of his article. Of its many factual errors and illogical conclusions, there are particularly serious impediments to understanding the saccharin issue and its implications for Congress in the upcoming effort to reconsider national policy on food safety. Animal studies: The risks associated with saccharin have been established not by one animal study, but three. Thomasson says the experiments exposed the animal to "extreme conditions.," in fact, the doses were quite routine for research of this type and are widely accepted in the scientific community.Two independent reviews, by the National Academy of Sciences and the Congressional Office of Technology Assessment, endorsed the validity of these experiements. Human studies: The largest study to date on whether saccharin causes bladder cancer in people has showed that it does elevate the risk for male consumers. So has a second study. The most recent National Academy of Sciences report on food safety policy called attention to the especially heavy consumption of diet soft drinks by children. All members of the Academy panel who testified earlier this year before Sen. Kennedy's health subcommittee expressed concern about the unrestricted consumption of such large amounts of saccharin by the one child in three in this country who drinks diet sodas. The Delaney Clause: The "culprit" in this scenario, contrary to what Thomasson contends, is not the Delaney Clause. He errs when he argues that the Delaney Clause has skewed regulatory judgments and led to the banning of many beneficial food additives. To the contrary, in its entire history, the Delaney Clause has been relied on the ban only two food ingredients, both minor and both obscure [for the record, they are chroanaline and Flectol H]. The Delaney Clause is not a tool frequently used by FDA; its existence is not required to take regulatory action against saccharin. The general safety provisions of the law are the ones relied on by FDA in making the vast majority of food additive decisions. This law says simply that additives must be proved safe for their intended purposes. By any objective standard of safety, saccharin would have to be regarded as unsafe and unsuitable for bulk use in the food supply. It makes no sense, either, to argue that the Delaney Clause diverts resorces from studying the mechanisms by which cancer originates. Just last month, scientists from the FDA-managed National Center for Toxicological Research reported on the results of a long-term multi-million dollar study. The purpose was to see whether a chemical known to cause cancer in a small number of experimental animals at high doses would do the same when given in low doses to a larger number of animals. The results provided strong support for two views held by most scientists [though not by Thomasson]: first, that there is no safe dose for a caricinogen, that is, a dose below which it will have no effect; and second, that high dose studies can accurately predict responses at lower doses. The study adds weight to the argument that when we deliberately add a carcinogen to the food supply, we are exposing our population to an increased cancer risk. Other research on toxic substances also is expanding, and not at the expense of budgets for other kinds of cancer research. Another defect in Thomasson's article is that he often does not mention the source of his "information." Several references suggest, though, that he drew heavily from a report prepared by Dr. Morris Cranmer of FDA. When scientists from the National Academy of Sciences studied the saccharin issue, the Cranmer report was available to them but it was scarcely mentioned in their final evalution. I suspect that NAS' assessment of it paralleled our own. FDA's review of Dr. Cranmer's report found it filled with speculative and unsubstantiated arguments about saccharin and sugar.In Thomasson's hands, these speculations -- that sugar causes cancer and saccharin prevents it -- become facts. Thomasson's smoke screen diverts attention from the real issues of food safety. The real issue raised by saccharin is not whether it causes cancer [there is now a broad scientific consensus that it does] or whether it yields a benefit [the NAS concluded that many people think it does, but that it has not been shown to]. Rather, the real issue is the much more complex question of how much risk we are willing to accept in our food supply. Since 1906, when the first federal food safety law was passed, the Congress has repeatedly concluded that the reduction and, where possible, elimination of risks from food is a worthy social objective. Those congressional determinations have led to our current system for regulating food safety. Under this system, food additives must be shown to be safe and food contaminants [often industrial chemicals that have contaminated the environment and therefore food] are reduced to the lowest level feasible. As a result of saccharin, the present law has provoked a flurry of criticism: it is criticized as being complex. This is true, but then food safety regulation is inherently a complex matter. Some say that the controlversy over saccharin demonstrates that the current law is no longer workable. Decisions under the current law sometimes will not meet with popular acclaim, but one case such as saccharin does not necessarily means that the fundamental principles of the law are invalid. Some say that the primary defect of the current law is that FDA cannot consider the benefits of additives. Using benefit-risk analyses as the basis for food safety decisions was considered and soundly rejected by the Congress 20 years ago. Later this year, the administration will propose to the Congress revisions in the food safety laws. It is not easy to agree on the desirable extent and nature of these revisions. There are no simple solutions. But any consideration of the food safety laws must address several fundamental issues, such as: To what extent, if any, should food processors be permitted to deliberately add to the food supply substances shown to cause cancer in laboratory animals? To what extent, if any, should the benefits of food additives be considered? Should economic benefits be balanced against risks to health in deciding whether to permit the use of an additive? And how do we do this? Should different regulatory standards be applied to the various different types of substances that are found in food? For example, should we require a greater showing of safety for substances that are deliberately added to food than we require for those substances that, because they have contaminated the environment, often cannot be avoided?