But over the last 30 years, the number of food dyes permitted on the market has been dwindling. Today there are only seven. The reason: many cause cancer in laboratory animals.

The Food and Drug Administration wants to ban several more color additives and recommended doing so to its parent agency, the Department of Health and Human Services, a year ago. But an industry extremely dependent on them has lobbied intensively to keep the dyes on the market and in the process has found some sympathetic ears in Congress and in the Reagan administration.

The dispute is not over whether the color additives in question -- called coal-tar dyes because they are derived from petroleum -- cause cancer in laboratory animals. Instead, industry officials have argued that the dyes present such a small risk to the public under current conditions of use that they can be considered "safe" under the anti-cancer Delaney Clause of the Food, Drug and Cosmetic Act.

"The issue is, do you want to ban something that poses no risk to the public?" asks Peter Barton Hutt, an attorney with the law firm of Covington and Burling, which has represented the Cosmetic, Toiletry and Fragrance Association, a trade association interested in retaining the dyes for use in cosmetics.

Officials at the FDA are not convinced, however, that the dyes are risk-free. And, they point out, the law puts the burden on the industry -- not FDA -- to prove safety. Says Dr. Sanford A. Miller, director of FDA's Center for Food Safety and Applied Nutrition: "All we have to say is that we don't think it is safe ." He adds, "I can't say it's safe until the questions are resolved."

At the heart of the current controversy in the food area is Red No. 3, which is found in about 2,000 different foods, including cereals, frostings, candy, vitamins, ice cream and pet food. According to an industry source, one of Red 3's most important -- and irreplaceable -- uses is in maraschino cherries in fruit cocktail because, unlike other available dyes, it does not "bleed" and turn the other fruit red.

Several studies conducted by industry showed that the color additive caused thyroid tumors in rats and mice at the highest dose level. After reviewing this data, FDA scientists in 1983 concluded that the dye is a carcinogen, an opinion confirmed by the National Toxicology Program, a division of the National Institutes of Health.

However, several industry groups have argued that the dye does not cause cancer when ingested in small amounts. They maintain that at high doses, Red 3 creates other metabolism-related changes in the body that in turn are the actual cancer culprit. Under such a hypothesis, Red 3 is a "secondary carcinogen," and a safe level of consumption can be set. In November, two trade groups, the Certified Color Manufacturers Association and the National Food Processors Association, submitted to FDA new short-term studies that they say prove this theory.

As letters from congressmen and senators, some from cherry-growing districts, flood the agency, pressure is building for FDA to have the Red 3 issue "peer reviewed," or submitted to an outside panel of scientists for its opinion on the color's risk. "There are some important questions that need to be resolved," says FDA's Miller. "One could legitimately say we need peer review on these questions."

But pressure to resolve the issue of Red No. 3 and nine other color additives (seven of which are not permitted in food but are used in cosmetics and/or drugs) is coming from another quarter: the Health Research Group (HRG), a Washington-based consumer organization that filed suit against FDA and HHS in January. The group has sued FDA and the department periodically over the years for failing to take action on color additives. This time, some FDAers think HRG may win.

Peter Lurie, staff researcher at HRG, says peer review is "simply a foot-dragging tactic," and charges that unnecessary peer review "has already occurred for some of these dyes." The suit asks the U.S. District Court in Washington to force FDA to ban 10 color additives -- three of which are used in foods, the remainder in cosmetics, drugs or both.

Cited in HRG's complaint is a March 30, 1984, memo from Mark Novitch, then acting FDA commissioner, to HHS Secretary Margaret Heckler recommending a ban on six of the additives. The memo said FDA scientists had determined that "recently submitted toxicity data clearly demonstrate that each of these color additives induces cancer in properly conducted animal feeding studies." The memo called Red 3 "of greatest public health concern" because exposure to it is high.

To get perspective on the issue, one has to go back about 25 years, when Congress passed the Color Additive Amendments to the Food, Drug and Cosmetic Act. The amendments required all color additives then on the market to be proven safe by those wanting to use them, but allowed FDA to set up a "provisional list" so the additives could be marketed while the industry-sponsored tests were being conducted. If shown to be safe, the dyes were to be "permanently listed."

Over the years, FDA permanently listed 126 additives and removed 63 from the market. Today only 11 color additives remain on the provisional list, but FDA has repeatedly extended their provisional listing to permit continued marketing. Between 1963 and 1977, FDA granted approximately 14 extensions for the 10 additives under attack by HRG. In 1977, another four years were granted for the industry to conduct long-term animal studies. For the past year or two, FDA has granted extensions approximately every two months; the current extension expires April 2.

But by last year FDA officials were clearly distressed by the possibility of further extensions. In the 1984 memo to Heckler, Novitch warned that "the credibility of the agency and the Department would suffer if decisions are not made soon on each of these color additives." He added, "If we do not move quickly, there is a strong possibility of lawsuits and adverse publicity about undue delay."

In the past, FDA has acted independently on major issues like color additives, but in 1982, HHS established a policy requiring its approval of all FDA decisions of significance. Since then, many FDA initiatives have stalled, resulting in what some say is a morale problem among agency scientists.

In this case, FDA was arguing forcefully for a ban of the six additives. Why didn't the Department of Health and Human Services concur? Rep. Ted Weiss (D-N.Y.), chairman of a House Government Operations subcommittee, sought to find the answer to that question in a hearing last October. Dr. Edward Brandt, former assistant secretary for health, said at the hearing that he signed off on the FDA memo recommending a ban on April 11, 1984, but the next day, after thinking it over, requested it back. "It is my understanding that neither the secretary of HHS or any member of her staff saw or read it," he testified. Shortly afterward, following a meeting with CTFA officials, Brandt requested an independent review of the scientific issues.

Evidence introduced at the hearing showed that officials of the Office of Management and Budget wrote to HHS in 1983 urging that one additive used in cosmetics not be banned. Weiss concluded at the hearing: "Lacking scientific expertise and having done no scientific research, OMB, on the basis of indiscreet importuning, attempts to get the Commissioner of FDA and the Secretary of HHS to reverse a decision based on scientific findings and conclusions."

Hutt says the industry was simply presenting its argument, "if you call that pressure." He added, "What we've done is make our argument known throughout government," saying the issue is not one of "narrow science" but for policymakers to decide.

A literal reading of the Delaney Clause, which states that an additive must be banned if it causes cancer in test animals, would require the color additives to be taken off the market. But Hutt argues that in the last 10 years, FDA has "reinterpreted" the Delaney Clause to permit carcinogens that pose an insignificant risk in the food supply. "A literal reading of the statute the Delaney Clause would not permit any of the policies FDA has adopted to make sense out of the Delaney Clause," he says. As to Rep. Weiss's contention that the Delaney Clause does not permit FDA to assess risk, Hutt says, "He's simply wrong."

FDA officials say they have never approved a food or color additive when the additive as a whole has been shown to cause cancer, although they have approved dyes when a manufacturing impurity, and not the dye itself, is carcinogenic. Even if Red 3 was shown to be a "secondary carcinogen," Miller told NFPA in a letter last year, the industry would still have to show there was a "clearly established threshold," below which the dye would be safe for consumption. FDA scientists believe studies necessary to prove this would take two to four years. In addition, a recent Canadian study indicates Red 3 may cause gene damage, in which case, according to one FDA internal memo, the "question of secondary carcinogenesis is moot."

HRG is concerned about several other widely used food dyes:

* Yellow 5, used in gelatin desserts, carbonated beverages, cereals, pet foods and baked goods. Also known as tartrazine, this dye is the only one you will ever see listed in the ingredient label specifically by name (the other dyes may be listed under the generic term "artificial color"). This is because many people who are allergic to aspirin are also allergic to Yellow 5. HRG is concerned about animal data which it says indicate a carcinogenic effect. An industry representative whose firm produces the color says the study is "about as clean non-toxic a study as you will find on a food additive." The data are under review at FDA.

* Yellow 6, used in carbonated beverages, cake mixes, candy and sausages. An industry consultant reviewing studies on this dye concluded that preliminary evidence showed the color additive caused kidney tumors. The dye, which is really an orange color, is under review at FDA.

* Blue 2, used in pet food, candy and beverages. HRG claimed this dye caused brain tumors, although FDA decided to approve the color additive permanently. HRG filed objections, but just this month, an administrative law judge at FDA upheld the agency's decision and ordered the dye permanently listed.

An HRG petition submitted to FDA in December expressed concern about the other three food dyes on the market -- Green 3, Red 40 and Blue 1 -- and predicted that "in a very short time, few if any . . . petroleum-derived food dyes will be left."