The Food and Drug Administration commissioner, Dr. Frank E. Young, recently turned down a request to create a new class of medication: nonprescription drugs with possible harmful side effects that could be sold only by pharmacists.

In Dec. 3 letters to the National Association of Retail Druggists and the American College of Apothecaries, Young said he was rejecting their petitions to establish a third type of drug, "sale by pharmacist only," in addition to the existing categories of prescription and over-the-counter (OTC) products.

Pharmacists had argued that they were best equipped to advise consumers at the time they purchase certain nonprescription drugs of possible harmful side effects, including cases in which a drug was recently switched from prescription to nonprescription status or contained new ingredients.

The retail druggists expressed particular concern about the recent approval of the popular painkiller ibuprofen for sale on a nonprescription basis, the first new nonprescription painkiller in three decades. Larger doses of ibuprofen have been available since 1974 on a prescription basis.

In approving ibuprofen, the FDA required that manufacturers provide labels warning aspirin-sensitive patients not to take the drug and urged that the warning be prominently displayed in promotional material.

But pharmacist groups cited the case as indicative of the need for a new "transitional" group of drugs. Some druggists even refused to put the painkiller on their shelves and instead provided it only to customers who asked for it. Others sold it, but sought to advise customers about its potential risks.

The two manufacturers of the medication, sold as Advil and Nuprin, and the FDA argued that the labeling was sufficient to warn consumers. Some critics complained that if the pharmacists got their way, they would have a monopoly on certain drugs and raise prices, while blocking their sales in outlets such as supermarkets and discount stores.

Young said it was "questionable" whether the distribution of over-the-counter drugs can be restricted. "Under the federal Food, Drug and Cosmetic Act. . . there is no provision for an intermediate class of drugs between OTC and prescription products."

Charles West, executive vice president of the retail pharmacists group, which represents about 30,000 independent druggists around the country, expressed disappointment at the FDA's decision, saying that "our approach would have protected public health while acting to lower health care costs by providing a mechanism whereby more prescription drugs could be made more available to consumers at greater convenience with lower cost." FLYING FOOD . . .

Concerned about the possibility of hazardous in-flight storage conditions, the FDA is stepping up its scrutiny of airline food operations. The agency sent an alert to the nation's airlines after routine inspections revealed that spoilable foods such as steak, chicken, fish, milk and non-dairy creamers were being loaded on aircraft with little or no dry ice and stored at unsafe temperatures.

The concern was prompted by regional FDA investigators in the New York area, who inspected 166 aircraft from 25 airlines at the Newark, LaGuardia and John F. Kennedy airports. Of the 142 planes that had food on board, 28 were storing it at improper or uncontrolled temperatures.

One FDA official noted that the food problem has grown worse recently because of flight delays caused by the expansion of the air traffic system.