Face masks sporting carbon filters typically come with a replaceable filter that helps remove bacteria from the air and, additionally, helps absorb particulate on the surface of the mask. While they may help purify the air around you, they likely won't increase the efficiency of filtering out viruses, said Davidson.

What face mask filters can I use for COVID-19?

• Paper products that you can breathe through, such as coffee filters, paper towels, and toilet paper.
• HEPA filters with multiple layers block small particles almost as well as N95 respirators, studies show.

But they might have tiny fibers that can get into your lungs.

Does a PM 2.5 filter for masks help with preventing the spread of COVID-19?

Cloth masks made of two layers of heavyweight cotton, especially those with a thicker and tighter weave, have been shown to be helpful in preventing the spread of respiratory droplets if worn correctly. Some masks have built-in pockets in which one may place a filter. Data on the use of additional filters is limited.