Transcript for Mask efficacy after months of use, when to change it
Back now with more on how to protect yourself during the pandemic. Masks have become a fact of life. After months of use when is it time for a change? Will reeve is here with tips. Good morning, will. Reporter: Good morning, George. Lots of people like me wear cloth masks like these all day every day. They are effective at containing the spread of covid-19 but experts warn they need to be replaced more often than you might think. As coronavirus cases continue to surge across the nation, mask wearing remains key to containing the spread. Proof here that droplets are capable of traveling nearly eight feet with no face covering. This is what's under the hood. Reporter: In a duke university Tes of 14 commonly used types of masks, one of the top performers, the polycotton mask. But with those masks such a regular part of our daily lives, is the one you might have been wearing for months wearing out? You can imagine that a mask as it gets older especially a cotton fabric mask might get looser. The more looser the fabricis, the more that really smart particles that you can't necessarily see, the more those can escape. Reporter: Joyce Chung wears it whenever she leaves her los Angeles apartment. We do try to maintain our masks so we try to wash them at least once a month. I think over time they do start to break down. Reporter: So how do you know when it might need replaced. If you can see light through the mask it's not going to do its job. If you see fraying at the edges or the elastic seems to be worn it's either curling or warped or it seems a little fragile, those are yourues to really throw those away and replace them with newer ones. I'm going to hold this clean mask up to the light. Still good. Epidemiologist Chris Johnson recommends cloth masks be replaced every two to three months to be safe. You can see that the nose piece, the metal nose piece to keep this in place is actually poking out. Reporter: And to check them for signs of wear and tear every time you clean them. This one is like way too loose. I can't even wear it. But used to fit closely here. As you can see it's too stretchy here to wear. Reporter: Our experts told us to think of your mask like a seasonal item so as you bring out those winter coats mix in a new mask and our Dr. Jen reminds us our cloth mask should be washed in the laundry after each use, George. They sure should. Thanks very much.
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