Processing aids facilitate the manufacture of tobacco products, such as by making cured tobacco less brittle. These include several ammonium compounds, carbon dioxide and ethyl alcohol. Ammonium compounds make reconstituted tobacco sheets more pliable.1
Combustion aids are used to control the smoking mechanics of cigarettes, such as by controlling the burning properties of cigarette paper. These can affect the rate at which burning occurs, and therefore the temperature. They include ammonium phosphate, sodium phosphate, sodium citrate and potassium citrate, which help to keep the cigarette lit.2-4
Fillers are chemically inert substances that are used to increase the bulk of the tobacco rod. Calcium carbonate is an example of a filler.4,5
Binders are used in reconstituted tobacco (made from stems and left over pieces of the tobacco plant) to make a paper-like material, that can be processed like normal tobacco lamina.6 Cellulose fibre, guar gum and phenylacetaldehyde may be used as binders.4
Preservatives increase the shelf-life of tobacco products. Benzoic acid and potassium sorbate are examples of preservatives in cigarettes.4
Anti-microbials may include chemicals that prevent the growth of bacteria, fungi (such as mildew), parasites and other microbes in tobacco during processing or storage. As an organic product, tobacco is susceptible to infestation with these microbes after harvesting, particularly bacteria and fungi.7 Menthol has some antibacterial and antifungal properties.8 Eucalyptol is an additive that may have antimicrobial properties.4 Note that fungicides used during the growing of tobacco may contaminate tobacco after harvesting and storage (but are not considered additives as such).
References
1. Bates C, McNeill A, Jarvis M, and Gray N. The future of tobacco product regulation and labelling in europe: Implications for the forthcoming European Union directive. Tobacco Control, 1999; 8(2):225-35. Available from: https://www.ncbi.nlm.nih.gov/pubmed/10478414
2. Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR). Addictiveness and attractiveness of tobacco additives. Brussels, Belgium 2010. Available from: http://ec.europa.eu/health/scientific_committees/emerging/docs/scenihr_o_031.pdf.
3. Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR). Final opinion on additives used in tobacco products. European Commission, Health & Food Safety, Directorate C: Public Health 2016. Available from: http://ec.europa.eu/health/scientific_committees/emerging/docs/scenihr_o_051.pdf.
4. Purcell K. The effects of cigarette additives on the palatability of cigarettes: A report to the Australian Department of Health. Australia: Purcell Consulting 2013.
5. Connolly GN, Wayne GD, Lymperis D, and Doherty MC. How cigarette additives are used to mask environmental tobacco smoke. Tobacco Control, 2000; 9(3):283-91. Available from: https://www.ncbi.nlm.nih.gov/pubmed/10982572
6. Stabbert R, Ghosh D, Clarke A, Miller J, Collard J, et al. Assessment of priority tobacco additives per the requirements in the EU tobacco products directive (2014/40/eu): Part 2: Smoke chemistry and in vitro toxicology. Regulatory Toxicology and Pharmacology, 2019; 104:163-99. Available from: https://www.ncbi.nlm.nih.gov/pubmed/30858113
7. Chattopadhyay S, Malayil L, Mongodin EF, and Sapkota AR. A roadmap from unknowns to knowns: Advancing our understanding of the microbiomes of commercially available tobacco products. Applied Microbiology and Biotechnology, 2021; 105(7):2633-45. Available from: https://www.ncbi.nlm.nih.gov/pubmed/33704513
8. Kopa PN and Pawliczak R. Menthol additives to tobacco products. Reasons for withdrawing mentholated cigarettes in European Union on 20th may 2020 according to tobacco products directive (2014/40/eu). Toxicology Mechanisms and Methods, 2020; 30(8):555-61. Available from: https://www.ncbi.nlm.nih.gov/pubmed/32746758