Pesticides

Pesticides have been of concern to tobacco industry scientists because of both the potential toxicity of their residues and the regulatory requirements of some governments. For example, a May 1958 memorandum from the B&W Research Department discusses the possibility of using an outside laboratory to conduct pesticide residue studies for the export department {1317.06}. The analyses may have been required for export of products to West Germany, which regulated levels of some additives and pesticide residues of tobacco products (see below).

A December 1968 letter from the Research Department at Imperial Tobacco in Bristol to the Tobacco Research Council in London documents the results of the department's analyses of DDT residues in samples of the 1967 US tobacco crop {1304.01}.

In our view these figures indicate an unacceptably high contamination [with DDT residues] of the tobacco and we think that they should be brought to the attention of the U.S.D.A. with the request that action is taken to ensure that levels in future crops are lower. {1304.01}

An early meeting of a group called the Agricultural Chemicals Study Group was suggested to review the matter. There seemed to be some urgency to the deliberations:

If there is support for our views it would then be possible for the matter to be raised with the U.S.D.A. in time for them to take some action in regard to the 1969 crop. {1304.01}

The Congressional Record for July 28, 1969, includes an eight-page exploration of the problem of pesticide residues in tobacco by Senator Gaylord Nelson (D-WI) {1307.01, pp. 2–3}. In this entry Nelson declares

his support for a ban on DDT and notes that tobacco has been exempted from regulations limiting the levels of pesticides used on crops.

The first page of a progress report from the B&W Leaf Division's review of the 1971 crop mentions DDT residues in US tobacco {1317.07}. The report indicates that US leaf has levels of DDT residues that "continue to approach the level demanded by the West German legislation, but the levels of maleic hydrazide are still very high."

A June 1983 memorandum from R&D within B&W discusses the advantages of substituting an insecticide named Fican-Plus for Diazinon {1317.01}. The proposed substitute is described as "not as toxic to mammals" and therefore "a desirable replacement"; it also might render the pyrolysis products (the results of burning the chemicals in a cigarette) less toxic. Once again, the company's research scientists are intent on reducing the potential toxicity of a chemical used in tobacco production, as well as the potential toxicity of pyrolysis products of the chemical.

The report of B&W's delegate to the industry-wide "annual pesticide residue meetings" for 1984 (see above) includes a description of a smoke panel test that was to become part of the evaluation of new pesticides for tobacco {1318.01}. This test was to be used to determine whether new pesticides altered the actual smoking experience in any way. The smoke panel is described as follows:

A toxicologist, Dr. Lamar Dale, was hired as an independent consultant. He is to review data packages from pesticide manufacturers when development of a pesticide for tobacco has progressed to the point that smoke flavor evaluations are needed. His evaluation will serve as a basis for judging the safety to tobacco company panelists who smoke experimental cigarettes treated with pesticides. {1318.01, p. 2}

Dr. Dale had been hired to do these evaluations for the entire US cigarette industry. Included in the specific information requested by Dr. Dale was "pyrolytic products at smoldering and ignition temperatures (acutely toxic products, i.e., HCN, CO, etc.)" {1813.02, Appendix III, p. 1}. The report noted that such information "will generally not be available. However, the safety to panelists can be judged through other available information requested" {1813.01, p. 2}. Thus, the committee representing the industry did not question the relevance to consumer safety of their consultant's requested information, but only its availability. The industry as a whole recognized that, in making the safety judgments about pesticide residues in cigarette tobacco, one must consider the toxicity of pyrolysis products (i.e., the results of burning them), not just the unheated form of the residue.

The fact that pyrolysis could increase the toxicity of additives had been recognized by Dr. Griffith in 1967, but the point seems to have been ignored by the industry in recent years. The additive list released by the cigarette companies in April 1994 indicated time and again that one material and another was GRAS or FEMA-approved (2), but nowhere in the listing is any consideration given to whether these additives are safe when inhaled.