Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. Thirdhand smoke can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.
You can still be exposed to thirdhand smoke if nobody around you smokes. After smoking stops, tobacco smoke residue can remain on surfaces and in dust for years. You can be exposed to thirdhand smoke when your skin comes in contact with a polluted surface. You can also breathe in thirdhand smoke chemicals and particles that off-gas. You can also get exposed when you put objects polluted with thirdhand smoke in your mouth. Thirdhand smoke sticks to the clothes, skin, and hair of smokers. When smokers move into a smokefree environment (e.g., workplace, elevator, hospital, airplane), they carry thirdhand smoke residue into that space. Thirdhand smoke can stick to nonsmokers exposed to secondhand smoke too.
Researchers found thirdhand smoke in homes with strict no-smoking rules. Researchers found thirdhand smoke in the homes of nonsmokers where smokers previously lived. Thirdhand smoke can be detected in non-smoking rooms at hotels that allow smoking only on the premises, and inside cars where drivers or passengers have smoked. Thirdhand smoke persists in environments frequented by smokers including cars and movie theatres with smoking bans. Surprisingly, scientists discovered thirdhand smoke in neonatal intensive care units (NICUs) and other high-risk hospital settings. Smokers or nonsmokers living with smokers that visited the facility left behind thirdhand smoke residue.
People’s previous behavior in an enclosed space can leave behind a toxic legacy that can expose others to thirdhand smoke, even if no one around them is smoking.
Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.
Updated: April 2023
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