Does a HEPA Filter Remove Ozone?

Although HEPA filters are excellent at capturing nanoparticles, they don’t remove gases like ozone. To get rid of ozone, you need an activated carbon filter, also known as a “charcoal” filter.

Carbon filters

How Effective are Carbon Filters at Removing Ozone?

One study was carried out in an office building in Sacramento, California. Researchers tested ozone levels in the air ducts before and after installing carbon filters. 

The results showed a 70% reduction in ozone levels after carbon filters were put in place.

Do Fiber Filters Remove Ozone?

Researchers also tested on fiber filters which proved both HEPA filters and MERV furnace filters had no effect on ozone gas. 

What is the Health Effect of Ozone?

Sunny days with high temperatures are the optimal condition to produce ozone. Ozone is made when sunlight reacts with pollutants from cars and power plants. Hence, most ozone comes from outside, not inside. 

This puts outdoor workers, active individuals and children at risk of coughing, lung infection, and asthma attacks. This is because children breathe faster and have more lung surface area than adults, which means they inhale 50% more air per pound of body weight.

The health effects of ozone

How Can I Protect Myself From Ozone?

Before going outside, check the Air Quality Index (AQI) for ozone to make sure that the levels are safe. If you experience any symptoms related to ozone exposure, it is recommended to limit your time spent on outdoor activities, particularly high-intensity sports, on hot and sunny days.

AQI ozone chart

Bottom line: HEPA filter vs. Carbon filter

HEPA filters do not remove ozone gas. If you’re concerned about indoor ozone gas pollution, your best option is to use an activated carbon filter.

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