Insecticides and the Pure Food Law

P. B. Dunbar.

In this paper I discuss the provisions of the Federal Food, Drug, and Cosmetic Act of June 25, 1938, as they concern insecticidal residues, and recent activities under these provisions.

First, a few fundamentals: (1) Congress, in passing the law, recognized that the use of insecticides is necessary, both to bring many agricultural food crops to maturity in a condition suitable for human consumption and to protect many foods against insect depredations during manufacturing operations and storage. (2) By and large, insecticides are poisons, their toxicity varying only in degree. (3) The terms of the law do not preclude the use of insecticides, but they make provisions which guarantee that when they are used the health of consumers eating foods so treated shall be protected.

The House Committee on Interstate and Foreign Commerce of the 75th Congress, in a report on the bill which became the law in 1938, made the following comment on section 406, which relates specifically to insecticidal residues :

"This subsection first prohibits the unnecessary addition of poisons. Where such additions are necessary, the establishment of tolerances is authorized, based upon the practical necessities for the use of poisonous substances. It is well recognized that an adequate fruit and vegetable supply could not be brought to maturity without the use of toxic insecticides and fungicides. But the situation is made extremely complex by the number of poisonous substances used for different crops in different localities, and by contaminations which unavoidably occur in many manufacturing processes. The purpose of the subsection is to insure that the total amount of poisons the consumer receives will not be sufficient to jeopardize health. The needs of each branch of the food-producing industry can be met and the public health can be adequately protected."

The law attacks the problem of protecting the public against poisons in foods by defining any food as adulterated if it contains a poisonous or deleterious substance that may render it injurious to health, or if it contains any such substance that is not required in the production of the food or that can be avoided by good manufacturing practice, or (where it is so required or cannot be so avoided) if it exceeds tolerances prescribed by the Federal Security Administrator after public hearing. In prescribing a tolerance, the law directs the Administrator to take into account the extent to which the poisonous or deleterious substance is required or cannot be avoided in the production of each food and the other ways in which the consumer may be affected by the same or other deleterious substances. In any event, the Administrator is enjoined by the statute to prescribe the tolerances at such levels that the public health will be protected.

This law has been on the statute books for more than a decade. Undoubtedly numerous tolerances would have been established long before this had it not been for the intervention of the Second World War and the resultant preoccupation of all concerned with other urgent matters. During the war period and immediately afterwards, many new and potent insecticides were developed. Scientists knew little about their toxicity, either to the person who applied the sprays or to the consumer who ate the finished food product. In some instances accurate methods for the estimation of the residual spray left on or absorbed by the food product were lacking. It was not known whether the residues remained intact, whether they were altered by weathering to nontoxic or more toxic residues, whether they could be removed by washing, or whether they were absorbed into the plant structures and therefore could not be removed.

It is a commentary on the changing attitude of the times that with the multiplication of new spray substances manufacturing groups, growers' organizations, entomologists, plant pathologists, and physicians, as well as consumer groups, began to recognize that it was high time to attack the residue problem and the question of safe tolerances in a fundamental fashion. The Bureau of Entomology and Plant Quarantine and other bureaus of the Department of Agriculture, the Interdepartmental Committee on Pest Control, organized groups in the insecticide-manufacturing industry, scientific workers in entomology and plant industry, food manufacturers using the raw materials of agriculture, and the growers themselves have shown a constructive interest in reaching some kind of a sound conclusion on the subject of spray-residue tolerances.

And so, in January 1950, it seemed that everyone was ready to begin the hearings on statutory tolerances. The hearings, called by the Federal Security Administrator, were in session, with occasional recesses, from January 17 to September 15, 1950. Those who attended them were impressed with the spirit of cooperation and good will manifested throughout the sessions.

The hearings were limited to the tolerances on fresh fruits and vegetables. Testimony on the necessity for using any particular insecticide or fungicide on any particular fruit or vegetable came first. Next, the question of which pesticides are poisonous or deleterious in themselves was thoroughly explored. Subsequent sessions dealt with "the amounts of these substances which are poisonous or deleterious, which are received from all sources by consumers," and with "the toxicity of the substances for which limits are to be established." The final session was devoted to relevant evidence not previously covered. Evidence was also taken at that time on amending the fluorine tolerance which had been duly promulgated in 1944 and soon after nullified on a legal technicality.

The record consisted of 9,000 pages of testimony (by 255 witnesses) and nearly 1,300 exhibits. It encompassed the investigations of scientific workers in many fields, the considered opinions of medical and toxicological minds, and factual information bearing on the aggregate intake by the consuming public of agricultural and other poisons. Many have repeated the opinion that the value and completeness of the record is unequaled anywhere.

An editorial in "Agricultural Chemicals" for April 1950 said :

"Assimilation of this material may take a long time, but we have a feeling that eventually it will be the means of correcting much of the confusion which has existed in the field for several years. The establishment of tolerances for pesticides old and new will set universally-recognized standards to guide future planning.

"It is doubtful that without the hearing, such a collection of data would ever have been assembled. It was a job too big for the industry itself to have undertaken; both from the standpoint of prohibitive cost and because of a lack of proper coordination. Also, the findings of an investigation conducted entirely by manufacturers could be regarded as biased."

TOLERANCES are sure to exert an enormous stabilizing effect. But it would be the worst sort of Pollyanna philosophy to relax into an attitude of complacency. Insects do not stand still; in fact, some of them seem to meet the situation by breeding poison-resistant strains. Teams of entomologists and chemists, in and out of Government, are constantly tailoring new insecticides to measure. Among the other scientists, who are by no means idle, we must give credit to the toxicologists, food technologists, analytical chemists, and others who are all fighting the insect menace, without losing sight of their primary obligation to safeguard the public health.

What of the future? In our fight against an implacable enemy, perhaps we will learn how to kill with a rapier instead of a bludgeon. Perhaps, too, we can develop rapiers that will do their job on insects but will not affect man and his domestic animals. The synthesis of additional naturally occurring organic agricultural poisons is one of the hopeful approaches. After all, most of these natural products seem to be relatively benign in their potential threat to consumers, as well as to soils and crops.

It is the men of vision who will win this battle. Too often in the past scientific thinking has had but a single objective among the many aspects of the insect war. Such slogans as : "Kill all the insects," "Produce fruit without spot or blemish," "An enormous yield is everything," "We must do something quick; never mind the future," and the like, have all borne bitter fruit. There is no one answer to the "insect menace" any more than to the other problems of modern civilization. "Of nothing too much" was the Greek motto, and it's worth remembering now.

P. B. DUNBAR was Commissioner of Food and Drugs in the Food and Drug Administration of the Federal Security Agency until his retirement in May 1951, after 44 years of Federal service.