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Chapter 6 Agricultural Chemicals and Cigarette Additives
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Diethylene Glycol (DEG)

Humectants, or moisturizing agents, are used in cigarette tobacco blends to assist with aerosol formation and thus make cigarette smoke "milder." The more that nicotine can be dissolved in the tar droplets, the less irritating the smoke is to the consumer's throat and the easier it is to inhale. Diethylene glycol, more familiar to most readers as an automotive antifreeze, was introduced as a humectant in cigarettes in the 1930s by Philip Morris.


Humectants were reviewed by BAT's internal Additives Guidance Panel in April 1965 {1310.01}. The minutes of the April 9 meeting make the following observations about humectants:

Di-ethylene glycol After some discussion, the Panel members present agreed that because a) there is a known cumulative effect of small doses of this material in the kidneys, and b) there are some other doubtful aspects, it would advise against its use.

Glycerol as a tobacco additive The Panel took the view that, although there was no known reason at present to suppose that this material should not be used on tobacco products, it should, in view of the observations (not supported by references) made on page 62 of the U.S. Surgeon General's Report "Smoking and Health" [the 1964 report] and because of its wide use in the Group, be investigated by R.&D.E. [Research and Development Establishment] both biologically and chemically.

Propylene glycol as a tobacco additive The Panel agreed that this material should also be investigated by R.&D.E. both biologically and chemically. {1310.01, pp. 1–2}

The 1964 Surgeon General's report stated (15, p. 62):

Cigarette manufacture in the United States includes use of additives such as sugars, humectants, synthetic flavors, licorice, menthol, vanillin, and rum. Glycerol and methylglycerol are looked on with disfavor as humectants because on pyrolysis [burning] they yield the irritants acrolein and methylglyoxal. Additives have not been used in the manufacture of domestic British cigarettes since the Customs and Excise Act of 1952, Clause 176, and probably longer, inasmuch as Section 5 of the Tobacco Act of 1842 imposed a widespread prohibition on the use of additives in tobacco manufacture.

Despite the recommendation from the Additives Guidance Panel, B&W was still using DEG twenty years later. In June 1984 R. H. Sachs, deputy general counsel for B&W, wrote to Ernest Pepples, J. G. Esterle, and C. J. Rosene about recent discussions between B&W and Union Carbide, the company that was selling diethylene glycol to B&W {1322.02}. In the course of the discussions, a Union Carbide sales representative said that the company had not known that B&W was using DEG in smoking products and that it would not sell DEG to B&W for this purpose. According to Sachs,

Scientific references were cited to us as the bases for their action. Our scientists read the references, but could not see what Union Carbide was so upset about.

We received a letter from the Union Carbide sales representative stating that DEG could not continue to be used on smoking tobacco because of health concerns, that Union Carbide would be glad to supply a substitute, and that Union Carbide only recently found out about our use of DEG on smoking tobacco.


I contacted the Union Carbide General Counsel to discuss the matter. After an investigation, a lawyer in his office called me to say:



Union Carbide had absolutely no problem with our use of DEG on smoking tobacco or cigarettes.


Union Carbide had mistakenly thought that we were using the product in chewing tobacco . They are of the opinion that the use of DEG in chewing tobacco would be a health hazard because it would be "ingested".


The sales representative was in error in writing the letter. Union Carbide would draft a follow-up letter that we can review before it is sent.

They are willing to cooperate in any way they can to rectify this situation.

While Union Carbide is satisfied that our continued use of DEG in smoking tobacco does not pose a health hazard, we should not let the matter rest there. If the "ingestion" of DEG applied to chewing tobacco is a problem (as Union Carbide seems to indicate it is), then how is it that they are so sure that its inclusion in smoking tobacco poses no problem?

We will look into this matter further [emphasis in original]. {1322.02, pp. 1–2}

The memo includes handwritten notations indicating that Earl (Kohnhorst) asked Gil Esterle whether the effort to eliminate DEG was continuing. Esterle replied that it was. He noted that DEG was not "Generally Recognized as Safe" by either the FDA or FEMA, and that it was not used in foods.

[I]f we need to someday release to government we will need to vigorously defend and public reaction would be negative (I don't trust confidential disclosures to government). We should replace but with a good match. {1322.02, p. 1}

The list of additives released by the tobacco industry in April 1994 does not include DEG (2).

Public relations seems to have become the guiding force for managing potentially toxic additives such as DEG, as it finally became for dictating how to handle matters related to the toxicity of tobacco (see chapter 4). The operative approach was that ingredients for cigarettes must be proven dangerous, and an acceptable substitute be available, before changes would be made. The usual expectation for consumer products, however, is that safety should be established before a product is used.

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