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Monday, Aug 17, 2026

Do N95 masks protect against ozone?

Cassis Tingley, The Colorado Sun
no

Federal health and safety authorities have not approved N95 or any other disposable face mask for protection against ozone. 

Though some mask models like Moldex advertise a carbon layer insert to help filter “nuisance” level ozone, these have not been approved by federal authorities. 3M, a face mask manufacturer, found no definitive evidence the company’s disposable face masks protected against nuisance-level ozone during internal testing.

Surface-level ozone forms when two types of air pollutants, volatile organic compounds and nitrogen oxides, react with each other.

Colorado’s ozone levels are higher than normal this year, with the state’s nine-county ozone nonattainment area already seeing 51 days above the federal ozone limit as of Aug. 5. Last year, that area surpassed federal limits on 23 days.

Exposure to ground-level ozone can lead to respiratory issues like throat inflammation and difficulty breathing.

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