If you're considering buying an air purifier, you have choices. But if you want an air purifier that will eliminate cigarette smoke, you're out of luck.

Tobacco smoke is made up of gaseous pollutants and particulate matter. Most air purifiers, also called air cleaners, are not designed to remove gaseous pollutants.

Mechanical air filters, such as high-efficiency particulate air (HEPA) filters, and electronic air cleaners, such as ionizers, target particles. While the use of air cleaning devices can help reduce levels of smaller airborne particles, research suggests that the devices aren't 100 percent effective. Air cleaners also might not decrease harmful health effects caused by indoor pollutants such as cigarette smoke.

Other air cleaners generate ozone, which is a lung irritant. At levels that don't exceed public health standards, ozone has little ability to remove air contaminants such as cigarette smoke.

The best way to protect nonsmokers from secondhand smoke is to not allow smoking in your home. If you smoke, this is another good reason to stop.

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Nov. 24, 2015 See more Expert Answers