AbstractTobacco additives play an important role in the manufacturing and for the quality of tobacco products, particularly cigarettes and roll-your-own tobaccos. Attention is increasingly given to the potential effects of additives on consumer behavior and health. This review is intended to compile, collate and - to some degree - evaluate the wealth of pertinent scientific information available from the published literature and other special sources. At first, the reasons are set forth for the use of additives in cigarette manufacturing. In response to the growing controversy over the attractiveness and addictiveness of smoking, the clarification of terms and concepts is followed by a detailed discussion of two kinds of substances with particular relevance: Additives like ammonium compounds that are claimed to increase nicotine availability, and additives that are claimed to increase nicotine addictiveness.The composition and toxicity of mainstream smoke of cigarettes with and without additives are assessed in several respects. The potentials of pyrolysis studies are explored by looking at a number of key studies and some basic considerations regarding in vitro and in vivo toxicity testing are addressed. Five major literature reviews on additives published between 1994 and 2004, and the results of several comprehensive experimental studies covering a large range of additives, released between 2002 and 2012, are dealt with in detail. Single tobacco additives of particular importance (menthol, glycerol, 1,2-propylene glycol, sorbitol, sugars, cocoa, licorice, citric acid, triacetin, and ammonium compounds) are discussed in dedicated chapters, which are generally subdivided into special sections: Use and toxicological assessment; inclusion level in cigarettes, transfer and pyrolysis; attractiveness and addictiveness; effect on cigarette mainstream smoke composition; effect on cigarette mainstream smoke toxicity. Epidemiological findings and data obtained by the biomonitoring of smokers consuming cigarettes with and without additives are compiled and interpreted specifically for American blend cigarettes, Virginia cigarettes, “French” (dark) cigarettes and menthol cigarettes whereby the focus is on the effects of additives on smoking topography and potential health risks.Opinionated reviews were published in recent years that are compromised by arbitrary selection of sources and unbalanced views. Leaving those unconsidered, the aggregated scientific knowledge shows that tobacco additives have only occasional and limited effects on cigarette mainstream smoke composition, which are almost never reflected in the results of toxicological in vitro assays or in vivo studies. This supports the conclusion that tobacco additives are not likely to increase the known health risks of smoking. There is also no evidence for sustaining claims that certain additives increase nicotine availability or nicotine addictiveness.
Influence of Additives on Cigarette Related Health Risks