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  2. Indoor Air Quality (IAQ)
  3. Indoor Air Pollutants and Sources

Secondhand Smoke and Electronic-Cigarette Aerosols

Recent Webinar

Going Smoke- and Vape-free in Multiunit Housing!

Date: Nov. 19, 2024

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On this page:

  • Smoking, Vaping and Contaminants Indoors
  • Secondhand Exposure
  • Reducing Exposure Indoors

Related pages:

  • Secondhand Tobacco Smoke and Indoor Air Quality
  • Secondhand Electronic-Cigarette Aerosol and Indoor Air Quality 
  • Secondhand Marijuana Smoke and Indoor Air Quality 
  • Secondhand Smoke and Electronic-Cigarette Aerosol Resources

Smoking, Vaping and Contaminants Indoors

If you smoke or vape, please do so outdoors, away from indoor spaces. Doing so will help you, your loved ones, your neighbors, and others nearby.

If you want to quit, resources are available.

Smoking tobacco and marijuana — and vaping with electronic cigarettes and similar devices — releases chemicals into the air.

The fumes released from e-cigarettes are called aerosols, which are a mix of tiny particles and/or droplets in the air. 


Secondhand Exposure

When a person smokes or vapes, they inhale the chemicals in the product. People around the smoker or vaper are also exposed to these chemicals. This exposure is called secondhand exposure.

The types and amounts of chemicals these products release vary depending on several factors, including:

  • The type of product. 
  • The chemicals in the product. 
  • How much of the product is used.
  • How long the product is used for.     

Even after a person stops smoking or vaping, some of the chemicals released can remain indoors for a long time. These chemicals can build up on hard surfaces such as walls, tables and floors, and embed in soft surfaces like clothing, upholstery, drapes, bedding and carpets.

In some cases, these chemicals can be released back into the air, leading to thirdhand exposure. People experience thirdhand exposure when they touch contaminated surfaces or breathe the air where smoking or vaping chemicals are released from surfaces back into the air.  


Reducing Exposure Indoors

The only way to eliminate secondhand exposure is to prohibit smoking and vaping indoors, including in cars and other vehicles, and near air intakes and entryways to enclosed spaces. Doing so will help protect occupants from exposure to the harmful chemicals these products may release. 

Ventilation, filtration and air cleaning techniques can reduce these exposures, but they will not eliminate them. 

When smoking or e-cigarette use occurs outside, it should be done away from building air intakes, doors, open windows, vehicles, and other enclosed spaces.

Smokefree policies in homes, schools, offices, vehicles and other enclosed spaces improve indoor air quality when they are comprehensive and effectively implemented. Smokefree policies for tobacco smoke products have been extensively researched. These policies have many benefits, including:

  • Improving human health
  • Reducing health care costs for those exposed to secondhand smoke.
  • Reducing fire risk and associated costs.
  • Reducing property maintenance and rental turnover costs. 

Many smokefree policies pre-date the increased use of e-cigarette and marijuana products. Similarities between some potentially harmful chemicals released from marijuana and e-cigarettes and those released from traditional tobacco smoke products may point toward expanding smokefree policies to include these products. 

Research regarding smokefree policies that include marijuana or e-cigarette products is relatively limited. More research is needed to better understand the range of potential benefits of such policies. 

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Last updated on May 13, 2025
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