There is much confusion in the air purifier (opens in new tab) market about the difference between air purifiers and ozone generators. This is because ozone generators are increasingly sold as air purifiers, despite the fact that they do quite the opposite. Despite what any retailer will tell you, the Environmental Protection Agency (EPA) emphasizes that there are no federal government-approved ozone-generating devices for indoor occupied spaces. In fact, they're banned in California. These machines can be incredibly detrimental to your health because they need to produce dangerous levels of ozone to be effective. If you want to tackle odor in your home, you can check out our feature on what to use instead of an ozone generator (opens in new tab). To find out about the difference between air purifiers and ozone generators, just keep reading.
What is ozone, and why is it damaging?
Ozone is a gas that occurs naturally in our atmosphere and unnaturally at ground level. When it occurs naturally in the atmosphere, ozone acts as a protective layer against the sun's harmful UV rays. Nearer to ground level, ozone is created when air pollutants are expelled from power plants, cars, etc., and react chemically to the sunlight - hence ozone creation is more common during summer months.
On the other hand, ground-level ozone is harmful to the respiratory system, especially your lungs. According to the EPA, ozone has been known to reduce lung function, exacerbate asthma and make your lungs more vulnerable to infection. Basically, it's pretty dangerous stuff.
Ozone generators take the air in your home and apply an electrical charge, which splits the oxygen (O2) in your home into unstable atoms. These atoms can bond with many atoms in your home, including those which create odors (therefore eliminating them), but they will also bond with regular oxygen to create ozone (O3).
The FDA requires that indoor medical devices can only produce a maximum of 50 ppb (parts per billion) of ozone. The National Institute of Occupational Safety and Health recommends that indoor ozone levels should not be greater than 100 ppb. This is only a fraction of the ozone a generator will create to eliminate odors.
Air purifiers vs. ozone generators
Ozone generators are mainly marketed for their ability to remove unwanted odors from a room, and it's true that the creation of ozone can eliminate pesky cooking, pet-related or smoke odors. However, if you are truly looking to purify the air, look closely for air purifiers that advertise ozone-free technology.
Air purifiers are very different to ozone generators because they use a filter to remove pollutants from the air, then push the clean air out into your living space again.
When purchasing an air purifier, look for a filter that is UL listed, has an ETL mark or is certified by the Association of Home Appliance Manufacturers. All of these organizations, though not government run, are independent companies that test for safe levels of ozone production and compliance with other safety codes.