Sodium hydroxide is a caustic compound found in hair removal products. It was found in cigarettes in 1994.
"Medical Management Guidelines for Sodium Hydroxide (NaOH)." Agency for Toxic Substances and Disease Registry. 21 Oct. 2014. Web.http://1.usa.gov/ZGHEGD
"Nair 3 in 1 Brush on Cream Hair Remover-discontinued." U.S. Department of Health and Human Services. Aug. 2015. Web.http://householdproducts.nlm.nih.gov/cgi-bin/household/brands?tbl=brands&id=3002008
"599 Additives in Cigarettes - Sodium Hydroxide." U.S. Department of Health and Human Services, Public Health Service, National Institutes of Health, National Cancer Institute. Risks Associated with Smoking Cigarettes with Low Machine-Measured Yields of Tar and Nicotine. 19 Nov. 2001.http://cancercontrol.cancer.gov/tcrb/monographs/13/m13_complete.pdf
"Ingredients Added to Tobacco in the Manufacture of Cigarettes by the Six Major American Cigarette Companies." Truth Tobacco Industry Documents, 12 Apr. 1994: 44. List.http://legacy.library.ucsf.edu/tid/pjv11c00/pdf