Carbon monoxide is in tobacco smoke. Carbon monoxide is a toxic gas which can cause death.
"Smoking and Tobacco Control." 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: 185.
"Carbon Monoxide's Impact on Indoor Air Quality." United States Environmental Protection Agency. 05 Jan. 2016. Web.