What's in secondhand smoke?

Secondhand smoke includes the smoke that a smoker exhales (mainstream smoke) and the smoke that comes directly from the burning tobacco product (sidestream smoke).

Secondhand smoke contains toxic chemicals, including:

• Ammonia, used in cleaning products
• Benzene, found in gasoline
• Cadmium, a toxic metal
• Cyanide, used in chemical weapons
• Formaldehyde, an industrial chemical

It isn't just the smoke that's a concern, though. The residue that clings to household dust and surfaces is called thirdhand smoke. Young children are particularly at risk for thirdhand smoke exposure due to their frequent contact with contaminated materials, such as carpeting.