Related topics

CDC did not say wearing a cloth face mask traps carbon dioxide and ‘risks your health’

July 16, 2020 GMT

CLAIM: Photo shows a Centers for Disease Control and Prevention report with many claims about face masks, including that cloth masks trap exhaled carbon dioxide and collect mildew within 30 minutes, risking your health.

AP’S ASSESSMENT: False. The document in the photo is fake and falsely attributed to the CDC, the agency told The Associated Press. The CDC recommends the use of cloth face coverings in public settings to slow the spread of the coronavirus. 


THE FACTS: On July 13, a photo allegedly showing a CDC report began to gain traction on Facebook.

“Look CDC stated this case closed,” the caption read. It also featured the hashtag #maskoff.

The document in the photo, which racked up more than 200,000 views in two days, is made to look as though it was printed from a CDC webpage, but the CDC told the AP it is not real.

“CDC typically does not issue guidance or recommendations to the public in such a format,” said Jasmine Reed, a public affairs specialist with the agency. 

A closer look at a circled section of the text on the fake report shows its guidance does not match the CDC’s legitimate guidance on masks.

“CLOTH MASK: (DO NOT FILTER ANYTHING),” the text reads. “As you exhale, you are ridding your lung of contaminants and carbon dioxide. CLOTH MASKS trap this carbon dioxide the best. It actually risks your HEALTH, rather than protect it. The moisture caught in these masks will become mildew ridden in 30 minutes. Dry coughing, enhanced allergies, sore throat are all symptoms of a micro-mold in your mask.”

The AP has previously debunked posts that claim without evidence that wearing a face mask causes hypercapnia, a condition where too much carbon dioxide enters the bloodstream. 

While experts recommend users wash their cloth masks frequently, there’s no evidence wearing one for 30 minutes poses a risk of harmful mildew or mold build-up. 

The CDC says a cloth face covering may help prevent the wearer from spreading the virus to others.


Reed clarified the agency’s most up-to-date guidance on masks:

“CDC recommends that people wear cloth face coverings in public settings and when around people who don’t live in your household; especially, when other social distancing measures are difficult to maintain. Cloth face coverings may help prevent people who have COVID-19 from spreading the virus to others. Cloth face coverings are most likely to reduce the spread of COVID-19 when they are widely used by people in public settings.

Cloth face coverings should NOT be worn by children under the age of 2 or anyone who has trouble breathing, is unconscious, incapacitated, or otherwise unable to remove the mask without assistance.”


This is part of The Associated Press’ ongoing effort to fact-check misinformation that is shared widely online, including work with Facebook to identify and reduce the circulation of false stories on the platform.

Here’s more information on Facebook’s fact-checking program: