AS LESSONS in how not to regulate, it is hard to beat two recent actions by the Food and Drug Administration. One was the decision last month by FDA Commissioner Frank Young to allow six dyes, including the maraschino cherry's Red Dye No. 3, to remain on the market even though they have been shown to cause cancer in animals. The second was the granting of an "emergency exemption" from normal safety checks for a cattle drug that was known to leave cancer-causing residues in meat.

In both cases there is no doubt that the FDA acted contrary to law. The "Delaney clause" enacted way back in 1960 bans all foods, drugs and cosmetics that can cause cancer in humans or animals. FDA says it left the dyes on the market because the risk to humans in normal usage was exceedingly small. But there is no warrant in the law for such an exception. Similarly, there is no warrant in the law for any emergency exemption for animal drugs that don't meet agency standards. The FDA is making decisions in flagrant disregard of the law.

Having said that, we should add that you should take at something less than face value the cries of outrage arising from Congress. For if the FDA is acting lawlessly, it is doing so after receiving a lot of nudges and winks from Capitol Hill. It is widely recognized, for example, that improvements in testing over the last 25 years have enabled scientists to identify as cancer-causing some substances that seemed entirely benign under testing as it was known when the Delaney clause was enacted.

But Congress has been unwilling to tackle the hard job -- hard technically, especially hard politically -- of rewriting the law to bring it in line with current techniques. Hence, despite some protest, it effectively lets the FDA act outside the law. It should be needless to add that this is a terrible way to do the people's business. It means that an agency with exceedingly important powers is acting with no precise standards, subject to no effective review, in a way that may be scientifically and certainly is politically irresponsible. Blame the FDA, definitely. But blame Congress too.