Alleged Influence of Glycerine and Dfethylene Glycol upon the Irritating Qualities of Cigarette Smoke

Abstract

Mulinos and Osborne 1 have reported that the addition of small amounts of glycerine (1 to 5%) to cigarette tobacco definitely increases the irritation by the smoke, while the addition of similar amounts of diethylene glycol markedly decreases this irritation. For criteria they used the degree and duration of edema and redness produced in the mucous membrane of the rabbit eye after instilling into the conjunctival sac water presumably saturated with cigarette smoke. This method is not quantitative. Flinn 2 has since reported that in patients suffering from irritation associated with the smoking of cigarettes (coughing, irritation of the tongue, congested pharynx and larynx) such conditions were cured or improved by smoking cigarettes containing diethylene glycol. Prompt return of the throat congestion occurred in 80% of the cases when glycerine was substituted for diethylene glycol, and in nearly all cases the tongue condition returned with this change. This method is also not quantitative.

It is known that within physiological limits irritation of the mucous membranes of the mouth gives rise to increased salivation. Tobacco smoke is an irritant known to stimulate salivary flow. If glycerine added to tobacco increases the irritating properties of the smoke, one would expect a greater flow of saliva from the smoking of tobacco treated with this hygroscopic agent, and if diethylene glycol markedly decreases the irritative properties, the reverse would be expected. With these considerations in mind, experiments were undertaken to measure the salivary responses of 28 persons (26 men, 2 women). This method of measuring the degree of irritation caused by smoke was employed because the buccal cavity is normally the place of entrance of tobacco smoke, and because it gives an objective quantitative measurement.