Electronic air cleaners produce ozone

Research by Canada Mortgage & Housing Corporation suggest that electronic air cleaners of the type found in central forced air systems in Canadian houses produce ozone, which is a known respiratory irritant. Technical Series 03-117 reports the results of a research program done on a single unit in a home in Brantford, Ontario covering 185 hours of data. The air-handling system was operated continuously and all the windows were kept close.
It was found that continuous operation of the unit resulted in an interior ozone level rise of 7 to 10 ppb higher than that would be expected in a home without an electronic air cleaner. The researchers suggest levels would be higher in smaller homes and homes with smoother surfaces, e.g. those with smooth floors.
The report says that while current public health practice is to declare “bad air days” when outdoor ozone levels exceed 82 ppb for one hour. However, the report says recent research finds that ozone affects health at much lower ambient concentrations.