Reduced exposure evaluation of an Electrically Heated Cigarette Smoking System. Part 2: Smoke chemistry and in vitro toxicological evaluation using smoking regimens reflecting human puffing behavior

Abstract

Chemical analysis of up to 49 harmful and potentially harmful constituents (HPHC) in mainstream smoke, in vitro cytotoxicity of the particulate and gas/vapor phase of mainstream smoke determined in the Neutral Red Uptake assay, and in vitro bacterial mutagenicity of the particulate phase determined in the Salmonella typhimurium Reverse Mutation (Ames) assay are reported for three Electrically Heated Cigarette Smoking System (EHCSS) series-K cigarettes, the University of Kentucky Reference Cigarette 2R4F, and a number of comparator commercial conventional lit-end cigarettes (CC) under ISO machine-smoking conditions and a total of 25 additional smoking regimens reflecting 'human puffing behavior' (HPB). The smoking machines were set to deliver nicotine yields for the EHCSS and comparator CC derived from the 10th percentile to the 90th percentile of nicotine uptake distributions in smokers determined in two clinical studies. Duplication of the smoking intensity 'per cigarette' on a smoking machine may provide an insight into product performance that is directly relevant to obtaining scientific evidence for reduced exposure substantiation based on mainstream cigarette smoke HPHC-to-nicotine regressions. The reported data support an overall evaluation of reduced exposure to HPHC and biological activity.

Reduced exposure evaluation of an Electrically Heated Cigarette Smoking System. Part 8: Nicotine bridging – Estimating smoke constituent exposure by their relationships to both nicotine levels in mainstream cigarette smoke and in smokers

“…The ISO yields as declared on the cigarette packaging were as follows: Marlboro (M6UK; 6 mg tar, 0.5 mg nicotine, and 7.0 mg CO), Philip Morris One (PM1; 1 mg tar, 0.1 mg nicotine, and 2.0 mg CO), and EHCSS-K6 (5 mg tar, 0.3 mg nicotine, and 0.6 mg CO). Mainstream smoke was also analyzed for 44 additional HPHC according to ISO conditions plus 15 experimental smoking regimens reflecting 'human puffing behavior' (Zenzen et al, 2012). The data used represent a subset of the data set reported by Zenzen et al (2012) to illustrate the principle of the 'nicotine bridging' method.…”

“…This concept is used to evaluate HPHC-to-nicotine and in vitro toxicity-to-nicotine relationships for 2 conventional cigarettes (Marlboro, Philip Morris One) (M6UK, PM1) and the EHCSS-K6 smoked according to ISO and 15 different machine-smoking regimens to reflect 'human puffing behavior' Zenzen et al, 2012). Human smoking behavior was determined using nicotine uptake distributions derived from nicotine metabolite excretion data obtained in two clinical studies Lindner et al, 2011).…”

Higher cytotoxicity and genotoxicity of burning incense than cigarette

“…Strain TA98 detects frame shift mutations, and strain TA100 detects base-pair substitution at guanine-cytosine base pairs, while strain TA102 detects certain oxidizing mutagens, cross-linking agents, and hydrazines (Zenzen et al 2012). The numbers of revertants seen in these three strains are listed in Table 2.…”

Reduced exposure evaluation of an Electrically Heated Cigarette Smoking System. Part 5: 8-Day randomized clinical trial in Japan

“…The electrically heated cigarette smoking system (EHCSS) and EHCSS cigarette produces reduced levels of a wide range of toxicologically important cigarette smoke HPHC and significantly lowers the biological activity of mainstream smoke compared to conventional lit-end cigarettes in laboratory-based test systems (Werley et al, 2008;Zenzen et al, 2012). Electrical heating of the tobacco reduces pyrolysis, and produces smoke that contains lower amounts of most cigarette smoke HPHC.…”