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Ozone Exposure Standards, Chemical Effects of Air Cleaners on Indoor Ozone Concentration Levels
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• What is the recommended exposure limit for ozone gas?
• What indoor ozone levels may be generated by residential ozone generators and air purifiers?
• The effects of using ozone in buildings to "purify air" or to "kill mold"
• The toxicity of ozone gas and ozone gas exposure limits
• The hazards of ozone generators in buildings

Ozone is widely promoted by ozone generating equipment companies and cleaning services for use in indoor building environments to deodorize, disinfect, "kill" mold, and for "general health". Ozone generators are also promoted for use to reduce the level of airborne particles, pollen, animal dander, and allergens, ostensibly to improve indoor air quality for asthmatics and people with allergies.

While there are some important uses of ozone (such as for medical disinfection under controlled conditions), in general this is an idea which ranges from bad to dangerous in the home, and it is not recommended by the U.S. EPA nor other experts/agencies whose data we have reviewed.

This article explains the effects of using ozone in buildings for these purposes and warns consumers about misapplication of and health risks from ozone in buildings.

Because at least some of these claims are based on marketing desire, not good science, and because ozone exposure can be both dangerous and ineffective indoors, I have collected some information and references on this topic. © Copyright 2009 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

Ozone Gas Exposure Limits & Exposure Standards

General ozone exposure limits:

NIOSH REL: C 0.1 ppm (0.2 mg/m3);

OSHA PEL™: TWA 0.1 ppm (0.2 mg/m3), as we reported at Gas Toxicity Levels.

Table of Ozone Gas Exposure Effects, Risk Factors, & Standards & Limits

Note:

The columns in this table are separate subtopics and do not cross-correlate with one another.

Sources:

• Ozone generator hazards, US EPA
• OZONE HAZARDS

Ozone gas exposure hazards are further detailed at OZONE AIR PURIFIER WARNINGS and at Ozone Gas. Quoting from that article,

For ozone, that "threshold" concentration is 0.1 ppm. So long as concentrations are kept at or below that level, injury is not expected even in the most sensitive workers so long as their exposure durations coincide reasonably well with or are less than the 8 hr/day, 40 hr/wk regimen.

This "threshold" ozone gas exposure level is accepted by the American Conference of Government al Industrial Hygienists (and is called the Threshold Limit Value by that organization) and by the Occupational Safety and Health Administration, OSHA.

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Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

OZONE as a "CURE" for TOXIC INDOOR MOLD
WHAT IS OZONE- O₃
OZONE AIR PURIFIER WARNINGS
OZONE HAZARDS
STANDARDS FOR OZONE EXPOSURE
TESTING FOR OZONE
OZONE TOXICITY
OZONE ODORS, MOLD, REFS

• U.S. Clean Air Act - large PDF - epw.senate.gov/envlaws/cleanair.pdf
• "Ozone-Generating Air Cleaners and Indoor Air Chemistry" , U.S. Environmental Protection Agency, original document is available at: epa.gov/appcdwww/iemb/ozone.htm
• "Ozone Generators that are Sold as Air Cleaners", U.S. Environmental Protection Agency, original document is available at: epa.gov/iaq/pubs/ozonegen.html "EPA reviewed a wide assortment of this literature, including information provided by a leading manufacturer of ozone generating devices. In keeping with EPA's policy of insuring that the information it provides is based on sound science, only peer reviewed, scientifically supported findings and conclusions were relied upon in developing this document."
• Association of Home Appliance Manufacturers (AHAM) 1111 19th Street, NW, Suite 402, Washington, DC 20036, (202) 872-5955 www.aham.org provides information on air cleaners on their AHAM-certified Clean Air Delivery Rate site at www.cadr.org AHAM conducts four certification programs for each category - room air cleaners, room air conditioners, dehumidifiers and refrigerator/freezers. The air cleaner certification program is known as AC-1.
• The American Lung Association has an Air Cleaning Device fact sheet  www.lungusa.org/air/air00_aircleaners.html

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