Tobacco is made from the dried leaves of the tobacco plant. When used, tobacco has stimulant effects due to nicotine, a naturally occurring chemical that is highly addictive and toxic. Tobacco products contain many other chemicals, including substances introduced during cultivation and manufacture, such as pesticides, herbicides and fertilisers, as well as additives that may increase flavour, palatability and attractiveness.

The cultivation, manufacture and use of tobacco products can expose users to thousands of chemicals, many of which are harmful to health.