Why Car Air Purifiers Cannot Be Shipped to California

California ranks as one of the states with the worst air quality in the US, according to this report. There are various contributing factors to this issue, such as residential wood heaters, industrial processes, wildfires, etc. Yet the question still stands; if that is the case, why can’t Californians get portable air purifiers, including car air purifiers?

The answer to that question is closely tied to the methods of air purification that air purifiers use in general.

Air Purifiers: How Do They Work?

Air purifiers are complex devices that remove contaminants from the air and improve the quality of air indoors by employing a variety of different technologies. But, almost all of them use the main three technologies and different brands combine them differently. The most popular ones are HEPA filters, air ionizers, and ozonators.

The devices using these technologies purify the air by forcing the air through a filter (HEPA), by emitting negative ions (air ionizers) or by emitting a safe amount of ozone (ozonators).

Even if some car air purifiers aren’t strictly ozone-generating devices, i.e. employ a different base technology, some of them do emit ozone as an air freshener or catalyst for more efficient air purification.

The problem here is the dispute of what levels of ozone generation are actually considered safe.

The Legislation

For portable air-cleaning devices, including car air purifiers to be considered safe in California, they must meet the ozone emission concentration limit of 0.05 parts per million, as per CARB.

They claim that anything above that level may pose serious health hazards.

Meanwhile, other federal agencies in the US, such as the CDC and OSHA, have set an upper limit of 0.10 parts per million, nearly double the amount Californian agencies permit.

Other Factors

Other possible contributing factors to this decision might be related to the general air quality problem that California has. It is one of the states with the highest ground-level ozone pollution as well.

This type of pollution is the result of a chemical reaction in which sunlight affects existing pollutants produced by industrial buildings, power plants, and cars. Even though ozone high up in the atmosphere protects our planet from solar radiation, at ground level, it may be a contributing factor to smog and air pollution in general.


So, the reason that you might not be able to buy a car air purifier in California, or have it shipped there, is related to a legislative decision enacted in October 2010. This decision was made to combat certain health hazards that higher levels of ozone may cause in some individuals. Even though most of the devices produce safe amounts of ozone, this amount is disputed by different organizations.

Still, if you’re in the market for a new car air purifier and you want to learn all about the best ones, check our Best Car Air Purifier Reviews & Buying Guide for 2020.