Is your mask really stopping COVID spread? Stanford scientist explains use of candle test to check

If you can blow out a candle through your mask, that means too much air is getting through, potentially expelling COVID particles.
SAN FRANCISCO (KGO) -- The omicron surge has caused the CDC to finally update its mask guidance late last week, indicating a clear preference for the level of protection offered by N95 and KN95 masks.

It's also reopened the conversation about mask efficacy.

One test that has emerged on social media is the "blow out the candle" test. If you can blow out a candle through your mask, that means too much air is getting through, potentially expelling COVID viral particles to others near you.

RELATED: CDC encourages more Americans to wear N95 masks to slow spread of COVID-19

ABC7 News Anchor Kristen Sze performed the experiment Monday using three different masks: N95, surgical and cloth. She was unable to blow out the candle wearing N95 or surgical, but easily blew out the candle in a cloth mask.

Dr. Amy Price, a senior research scientist at Stanford's Anesthesia Informatics and Media Lab, joined Sze on ABC7 News 3 p.m. program "Getting Answers" Monday to discuss the reveals and limits of the candle test.

Price says the candle test is far from fool proof, but is a simple way to know when a mask is clearly not doing its job. She also talked about simple ways to improve your mask efficacy, including rubbing it with a latex glove for 30 seconds to create an electrical charge as an extra barrier for the virus to get through.

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Kristin Thorne has the latest on mask effectiveness and what experts are recommending.



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