Particles and Air Cleaners
This page last reviewed November 26, 2014
Reducing Exposure to Particulate Pollutants
Particulate pollutants are found both indoors and outdoors. They include very small (often invisible) particles from combustion sources such as motor vehicle exhaust, cigarette smoke, cooking, and woodburning activities; biological components such as pollen and mold spores, and dust mite allergens; and fine fibers such as asbestos. Particulate pollutants can cause a variety of harmful health effects. These effects include cough, nasal irritation, lung infection, allergy symptoms, asthma, chronic lung conditions, cancer, and premature death. There are many actions you can take to reduce your and your family's exposure to particulate pollutants.
"Reducing Your Exposure to Particle Pollution" (Fact Sheet - updated November 2014)
The most effective way to reduce exposure to indoor pollutants is to first remove sources of pollution or reduce pollutant emissions. A second important action is to provide adequate ventilation. If these actions do not resolve indoor air quality problems, sensitive individuals may benefit from using a central air filter or a good air cleaner in one or more rooms of the house. Air filters and air cleaners can only be effective if they are properly maintained.
How to Select a Safe and Effective Air Cleaner
- "Air Cleaning Devices for the Home, Frequently Asked Questions" (updated July 2014)
- "Air Purifiers: Filtering the Claims," Consumer Reports, December 2007, Issue 12, pages 48-51. Posted with permission; for educational purposes only.
- AHAM Verification Program for Portable Electric Room Air Cleaners
Air Cleaners to Avoid
Not all air-cleaning devices are appropriate for home use — some can be harmful to human health. The ARB recommends that ozone generators, air cleaners that intentionally produce ozone, not be used in the home. Ozone is a gas that can cause health problems, including respiratory tract irritation and breathing difficulty (Ozone and Health).
- List of Potentially Hazardous Ozone Generators Sold as Air Purifiers (November 6, 2007)
- Fact Sheet: Beware of Ozone-Generating Indoor "Air Purifiers" (March 2006)
For more information on ozone generating air cleaners, please visit our website at Hazardous Ozone-Generating "Air Purifiers"
The guidance document below provides information on the sources and health effects of indoor combustion pollutants and discusses actions you can take to reduce your exposures to them.
- Combustion Pollutants in Your Home - Guideline No. 2 (html) or (PDF - 8 MB)
- Combustion Pollutants in Your Home - Supplement to Guideline No. 2
Other Sources of Air Cleaner Information
The final research report below discusses the results of a survey of 2019 Californians on their use of air cleaning devices.
"Survey of the Use of Ozone-Generating Air Cleaners by the California Public" (Final Research Report January, 2007)
The Lawrence Berkeley National Laboratory has produced a multi-page summary of research results on the effectiveness, cost, and health benefits of filtration, which is linked below.