California Limits Ozone-Generating Air Purifiers

In 2006, the California legislature passed a law requiring the California Air Resources Board (CARB) to develop and adopt a regulation limiting the ozone emitted from indoor air cleaning devices. According to the U.S. Environmental Protection Agency, there is increasing evidence that the ozone from some of these devices leads to throat and lung irritation, and that, at levels considered safe, ozone does little to clean the air (see Good Ozone, Bad Ozone). In September 2007, CARB approved a regulation limiting ozone emission concentrations from these devices to 0.05 parts per million, matching a voluntary standard set by the Federal Drug Administration. When

Consumer Reports tested air purifiers in December 2007, it found several exceeded this limit, most notably those designed to generate ozone (as opposed to those that generate ozone as a byproduct of electrostatic cleaning). The regulation includes a testing method that must be approved by both the Underwriters Laboratory (UL) and the American National Standards Institute (ANSI) before the regulation can become law. CARB expects the regulation to go into effect in April 2008 and will give manufacturers two years to have their products tested and certified as meeting the emissions requirements. More information is available at www.arb.ca.gov/research/indoor/aircleaners/aircleaners.htm.