By synthesizing a number of different chlorinated terpene materials of varying degrees of chlorination, and submitting them to routine tests against house flies, he discovered that when camphene, a bicyclic terpene hydrocarbon of the formula Cl(,He, was chlorinated to above 60 percent, a unique waxlike product of excellent stability and high insecticidal activity against house flies resulted. When his tests were extended to include agricultural pests, he found that the high activity was even more pronounced.

Formulation of the material into dusts, wettable powders, emulsions, and oil-soluble concentrates became important. A considerable amount of application work was undertaken. It was estimated that 150,000 pounds of toxaphene would be required for extensive field tests. A pilot plant was set up to make it at Brunswick, Ga.

Quantities of toxaphene for commercial consumption first were produced in 1947. Testing has continued since, and the insecticide has been found effective against many pests. Construction was started on another toxaphene-manufacturing unit in the South.

In 1949 at the request of the Department of Agriculture, the trade name toxaphene was released, so that the word could be used commonly for chlorinated camphene having a chlorine content of 67-69 percent.

In the wartime research, many chemicals were screened for efficacy, and several phosphorus compounds were found to have insecticidal activity. Hexaethyl tetraphosphate, tetraethyl pyrophosphate, and parathion were soon on the market. They are effective against many pests not controlled by earlier materials. They therefore have been marketed even though they require special precautions in their manufacture and use.

In the production and marketing of parathion, for instance, a notable job has been done to insure proper handling. The technical material is shipped in welded, specially designed drums. For further protection of the handlers, the drums were reduced from a 500-pound size to 280 pounds as further assurance against accidents. Companies manufacturing the material limited its sale to processors who proved themselves properly equipped to formulate parathion. Their departments of industrial hygiene took an active interest in the handling of the chemical from then on and continued to cooperate with the processors to insure continued safety in handling and distribution.

Beyond that, the companies worked closely with the various Government agencies and devised a model label to be followed by formulators of the finished insecticide. They also prepared manuals for growers and safety precautions in the use of the chemical.

I give only a meager outline of what the insecticide companies undertake to insure safe use of a product. The toxicological studies, laboratory and field tests, chemical analyses, and many other costly and laborious activities are involved. Yet the consumer gets the materials cheap enough to pay him to apply them.

Many of the companies test 10,000 chemicals or more a year in the search for effective new products. Often several tens of thousands of chemicals are screened before one or two of real promise are found. When such a material is discovered, it is scrutinized immediately by a battery of scientists. If it appears that the insects to be controlled and the cost of production will create a new field of use or improve the control resulting from the use of existing products, the material undergoes a series of intensive tests. It may be tested in the manufacturer's greenhouses and experimental farms for its insecticidal effectiveness and for the reaction of the crop being treated. At the same time it is studied by company toxicologists and by toxicological laboratories throughout the country. Entomological and toxicological testing are coordinated so that data showing the insects that are controlled, and precautions to be observed in use, are available at as nearly the same time as possible. Often years are required to obtain adequate data.

Because of the competitive nature of the industry, most of this information is not published. I have no count of laboratories engaged in research on the toxicity of agricultural chemicals. Toxicologists have estimated that there are nearly 25 such laboratories and that their facilities are now being used to capacity.

It is also estimated that10 to 20 new agricultural chemicals are thoroughly studied for toxic hazards each year in the United States. Not all finally reach the market in quantity. Probably 500 to 1,000 products each year receive some study through the early stages of development but later are abandoned for various reasons. Toxicological research on a chemical that presents no hazards of food residues probably costs not less than 5,000 dollars, but sometimes, when residues of the chemical may occur on food products, the cost often exceeds 20,000 dollars.

A sampling of 20 manufacturers showed that the yearly expenditures for their research, including toxicological studies, is nearly 4 million dollars. Such studies represent fundamental work directed toward the protection of the health of all concerned workers in the manufacturing plant, farmers who apply the product, and consumers who buy and consume the commodities that have been sprayed or dusted.

For that reason, too, the industry has supported State and Federal legislation to regulate the distribution and use of insecticides, fungicides, and related products.

THE INDUSTRY is regulated at the State and the National level. Many State laws, some of them conflicting, present something of a problem to an industry whose members often sell their products throughout the country. Many States have tried to enact uniform legislation; in that effort, the industry has cooperated with the Council of State Governments, the Department of Agriculture, the National Association of Commissioners, and Federal and State regulatory officials. The combined efforts of those groups have produced the Uniform State Insecticide, Fungicide, and Rodenticide Act, which has been enacted into law in 19 States. Twenty-one States have other pesticide laws. The industry believes public interest will he served by the enactment of a uniform act in more States. The industry also actively supports a proposed Uniform Custom Applicators' Law, which was drafted by the Council of State Governments and other interested groups. Its purpose is to insure the safe application of pesticides from the air and by other means.

THE AGRICULTURAL CHEMISTRY industry has made noteworthy achievements, but it is not content merely to think of them. Its research is being intensified, with increased emphasis on fundamental studies. Substantial capital investments have been made in new plants. Manufacturing and processing techniques are being improved constantly. More efficient methods of distribution are being instituted. Toxicological studies and educational programs more and more seek to safeguard users of its products and the general public.

LEA S. HITCHNER is the executive secretary of the National Agricultural Chemicals Association, which was founded in 1933 and to which manufacturers of agricultural pest-control chemicals belong. A native of New Jersey and a graduate of the University of Pennsylvania, he has worked in the field of agricultural chemicals since his twenties. A member of the American Trade Association Executives, he is s a past vice president of that organization's New York chapter.