California Air Resources Board

What does the regulation do?

The California Air Resources Board (CARB) has adopted a regulation to limit ozone emissions from indoor air cleaning devices (AB 2276). Since 2010, all indoor air cleaners sold in, or shipped to, California must meet certain ozone emission and electrical safety standards. These air cleaners must produce an emission concentration less than 0.050 parts per million (ppm) of ozone. A good way to think about the size of 1 ppm is to picture one drop in 15 gallons of water. The packaging of the device must also be labeled and say "ARB Certified". 

What is ozone?

Ozone is a reactive gas comprised of three oxygen atoms and is a well-documented air pollutant. Sometimes, manufacturers of devices that intentionally generate ozone misleadingly refer to it as “activated oxygen,” “super oxygenated” or a similar term to give the impression that it is healthy. Ozone has a sharp odor similar to chlorine, but odor is not a good way to tell if you are exposed to ozone because ozone numbs the sense of smell. 

Why should I be concerned about ozone?

Ozone high in the atmosphere protects you from the sun’s harmful rays, but at ground level, where you breathe, it can be harmful to your health. Within hours, ozone can irritate the lining of your respiratory system and cause coughing, chest tightness and shortness of breath. It can also seriously damage the cells in your lungs and airways. Long-term exposure to ozone may both cause and worsen asthma symptoms and worsen lung disease; it might also increase the risk of premature death. The effects depend on the concentration of ozone in the air, your level of physical activity, how long you are exposed to ozone, and how sensitive you are to it. Ozone can also react with other chemicals, such as terpenes (fragrance chemicals that give pine or citrus scent to some household products), to produce toxic byproducts such as formaldehyde. Also see CARB's Ozone & Health page.

What types of indoor air cleaning devices are regulated?

Any air cleaner used in an enclosed space that can be occupied by people is covered by the regulation, except for “in-duct” air cleaners and those used for certain industrial applications, which are exempted in the regulation. Portable devices small enough for people to wear or carry, as well as devices designed to clean a room, building or vehicle, are regulated. Mechanical air cleaners, ionizers, electrostatic precipitators, photocatalytic oxidation air cleaners, UV devices, plasmacluster devices, corona discharge ozone generators, and others are all covered by the regulation. Some of these air cleaners do not produce ozone, some generate low amounts indirectly, and some generate large amounts of ozone on purpose.

When and where can I buy a certified indoor air cleaner?

Only devices that comply with the regulation may be sold or offered for sale, or otherwise introduced into commerce in California. Only certified indoor air cleaners that limit the production of ozone are legal in California, regardless of whether the product is sold in a store, online, in a catalog, or in some other way. Specific labeling is required on the packaging of the air cleaner, too. Labels for medical devices must comply with federal laws for medical devices and must also state “ARB Certified.” If you buy an air cleaner online or from a catalog, the advertisement must clearly indicate if a model cannot be sold in, or shipped to, California. If you want to know if your current air cleaner produces too much ozone, visit CARB's Hazardous Ozone-Generating "Air Purifiers" page and CARB's Potentially Hazardous Ozone Generators Sold as Air Purifiers page. There, you can find out which ones to avoid and obtain advice on how to select a safe indoor air cleaner. As devices are certified, they will be added to CARB's list of certified air cleaning devices.

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