Some devices that are advertised as “air purifiers”, air cleaners, or ozone generators purposely emit large amounts of ozone, the main component of smog! Not only are such ozone generators ineffective at cleaning indoor air, but breathing ozone poses serious health risks. The California Air Resources Board recommends that these ozone generators not be used.

The following is a partial list of portable air cleaners sold as “air purifiers” or ozone generators that can intentionally emit ozone. This list includes air cleaners sold primarily for residential use, plus some for commercial, in-vehicle, and personal use. Inclusion on this list is based on information available at the time of review. We are not aware of test results for these models using the UL 867 test protocol required by the air cleaner regulation. 

Until the testing required by the regulation is completed, we do not know if the ozone emitted will meet the 0.050 ppm limit specified in the UL 867 Standard. Exclusion from this list is not to be construed as endorsement by the California Air Resources Board. In-duct systems and other non-portable ozone generators are generally not listed here, with a few exceptions, but may generate potentially harmful levels of ozone.