Transcript for Will face masks with filters protect you?
We are back with a reality check on masks as more states and stores issue mandatory orders to wear them including Starbucks, Walmart and Sam's Club. Mask filters and the right way to use them. Good morning, Becky. Reporter: Good morning. We know cloth masks protect others but does wearing a filter inside of your mask give you the wearer extra protection? Masks, as of this week more than 20 states require people to wear them in public. The director of the CDC with an urgent plea for everyone. I think if we can get everybody to wear a mask right now I really do think over the next four to six weeks we could bring the epidemic under control. Reporter: Do masks that let you up certificate a filter offer better protection. Any mask will offer others from whatever secretions you might have but if you add that filter, then you're also adding a really good protection for Reporter: While the CDC doesn't offer specific guidance on filter they say they're more effective with more layers and the world health organization says nonmedical masks should ideally be made with three layers of fabric. The outer layer should be a water resistant fabric. The inner layer should be water absorbent and the midlayer acts as a filter. Reporter: And some may opt for any extra protection they can get. It's true that certain masks may filter out more or less viral particles but all masks filter out the majority of viral particles. Reporter: While there are masks with sewn in filter pockets available for purchase, you can also just cut a pocket into a standard mask and insert a disposable filter. If you use a filter you want to be sure and remove it from the mask before you wash it. Experts say that wash should be hot and the Marv should be tumble dried, not air dried. You know it's clean because you washed it yourself. You put in a fresh filter. And there you go. Reporter: The most important aspect of using a mask is fit and comfort. The more you wear it, the better, so while these coffee filters can work, they can get wet and make things a little too stuffy, Michael, so you can also buy a disposable filter online that may offer more comfort. Great advice, Becky. Thank you so much for that let's bring in Dr. Jennifer Ashton and, doc, can you take us through the experiment testing that we've seen about the effectiveness of facial coverings. The visuals are pretty striking. They are, Michael. And, remember, we're learning about this day by day. We've never really been in this situation before. So take a look at this video because it really shows how it's all about fit, fabric and feet apart meaning distance. You know, you see just how many particles come out of someone's nose and mouth just with breathing. Then when you look at different fabrics you do see a difference there and, of course, whether the mask or covering is over the nose really, really important. It has to be that way. But I want to be crystal clear, since there are no official recommendations about this at this point, it's really about using something. Something is better than nothing and keeping that distance apart is key. It's amazing to have visuals to back up your words. Thank you so much for that, doc.
This transcript has been automatically generated and may not be 100% accurate.