Kenneth F. Podraza

Toxicological Comparisons of Three Styles of a Commercial U.S. Cigarette (Marlboro®) with the 1R4F Reference Cigarette

Toxicological comparisons were made of three commercial cigarettes, namely Marlboro® full flavor, Marlboro Lights, and Marlboro Ultra Lights, with the 1R4F reference cigarette. The main comparison was a 90-d inhalation study with mainstream smoke at 150 mg total particulate matter per cubic meter, in Sprague-Dawley rats using 6 h/d and 7 d/w exposures. The principal endpoint was histopathology of the respiratory tract, along with examinations of free lung cell counts after broncho-alveolar lavage. Additional studies on mainstream smoke included Salmonella mutagenicity, cytotoxicity of particulate and gas/vapor phases, and analytical chemistry. The exposures produced effectively the same responses in each of the four groups, and the histopathology results in the commercial cigarette groups were also effectively the same. The 1R4F was also tested at 75 and 200 mg/m3, and most of the histopathology results obtained here showed dose-response relationships. The free lung cell responses were similar in the 1R4F/commercial cigarette comparison, and there were dose-related changes in the 1R4F groups, most notably for neutrophils. Most of the changes produced in the 90–d of exposure were resolved in a 42-d post-inhalation period. Responses in the in vitro and analytical assays for the four cigarettes were in general similar, when data were expressed either per mg TPM or per mg tar yield. There were judged to be no toxicologically meaningful differences between the profiles evaluated at similar smoke concentrations for the three commercial cigarettes and for the 1R4F using these assays.

The ability of the FTC method to quantify nicotine as a function of ammonia in mainstream smoke

Abstract Whether ammonia-forming ingredients added to tobacco and ammonia in smoke affect the ability of the Cambridge filter pad to trap nicotine in the Federal Trade Commission (FTC) method was examined. Three commercial cigarettes, two industry reference cigarettes, and four specially designed test cigarettes were used in this study to represent cigarettes with different construction and mainstream (MS) smoke yield characteristics. One of the commercial cigarettes, a US 1998 Marlboro Lights¯ King Size cigarette, was used as a control cigarette for the four experimental test cigarettes. The test cigarettes differed from the control cigarette as follows: first, a reduction in ammonia-forming ingredients added to the reconstituted tobaccos; second, no ammonia-forming ingredients added to the reconstituted tobacco; third, no ingredients at all added to the reconstituted tobaccos; and fourth, no ingredients at all added to the entire tobacco blend. An XAD-4 tube was placed downstream of the standard Cambridge filter pad in the FTC method to trap the gas-vapor phase nicotine for subsequent analysis. The Cambridge filter pad used in the FTC method was determined to provide greater than 99% trapping efficiency for MS smoke nicotine from cigarettes with widely different soluble ammonia levels in filler and MS smoke ammonia yields.