After 24 years of study, the Food and Drug Administration has appointed a new panel to review past research indicating that six widely used food and drug dyes might cause cancer.

In the meantime, use of the dyes can continue in the food, drug and cosmetic industries, which contend that they are safe, the FDA said.

The FDA said last week that government scientists will look at past studies to determine whether enough is known to act. They will not recommend what action to take, although the decision has been pending since 1960, and action was to have been taken by 1963.

A public-health activist who is seeking to ban the dyes and a food processing industry spokesman said last week that they believed that the evidence for their case is clear, without further study.

But they parted company there, with the activist calling the decision "outrageous" and the industry spokesman calling prudence "just a good regulatory position."

Dr. Sidney M. Wolfe, head of the Health Research Group organized by Ralph Nader, noted that the FDA scientific staff called for a ban on the substances last year. "The decisions are not being made on the basis of science or the law, but on . . . what is most pleasing to the regulated industry," Wolfe charged.

Dr. Harry Mussman, executive vice president of the National Food Processors Association, whose organization is concerned only with the food dye Red No. 3, said his group believes that the dye has been proven safe. He added that he has no objection if the FDA wants to "take some additional time to elicit additional information."

The FDA staff last year recommended banning all six dyes because studies linked them with cancer. Industry groups say later studies show no significant risk.

Besides Red Dye No. 3, which is used in food, the other dyes involved are Red Nos. 8, 9, 19 and 37 and Orange No. 17, which are used in drugs and cosmetics.