To slow the spread of the novel coronavirus that causes COVID-19, the Centers for Disease Control and Prevention recommends wearing cloth face coverings in public places where social distancing is difficult to maintain, such as grocery stores.

The CDC on Wednesday reported the results of a lab experiment that spaced two artificial heads 6 feet from each other and checked to see how many coronavirus-sized particles spewed by one were inhaled by the other.

The researchers found that wearing one mask — surgical or cloth — blocked around 40% of the particles coming toward the head that was breathing in. When a cloth mask was worn on top of a surgical mask, about 80% were blocked.

When both the exhaling and inhaling heads were double-masked, more than 95% of the particles were blocked, said the CDC’s Dr. John Brooks.

“The first challenge is to get as many people as possible masking. And then for those that do mask, to help them get the best benefit out of that mask,” Brooks said.

On June 23, Gov. Jay Inslee made face coverings mandatory statewide for most people in public.


The use of nonmedical masks can reduce transmission of the virus by people who are infected but aren’t experiencing symptoms. Masks are most effective when worn consistently and properly in order to avoid contaminating the hands or face of the user.

Here’s how to protect yourself and others when wearing a mask:


  1. With clean hands, fit the mask to cover your mouth, nose and chin.
  2. Secure it tightly to minimize gaps between your face and the mask.
  3. Once it’s on, do not touch or adjust it. Wash your hands.


  1. Handling only the straps, untie or unloop your mask from behind and pull it away from your face. Do not touch the front of the mask, your eyes, nose or mouth.
  2. Immediately throw the mask in the laundry, or the trash if it’s intended for single use. Wash your hands.


  • Make sure your mask covers your face snugly but comfortably.
  • Remove and dispose of paper masks and other personal protective equipment, such as gloves, in the garbage before you get into your car or home.
  • To avoid cross-contamination, consider carrying a separate bag to put your soiled mask in if you are going to bring it home to launder.
  • Always wash your hands before and after handling your mask.


  • Don’t pull your mask down. If you touch it, wash your hands and put on a clean one.
  • Don’t continue to use your mask if it gets damp. Replace it.
  • Don’t reuse single-use masks. Wear a fresh one every time.
  • Don’t wear medical masks or respirators, as those should be reserved for health care workers.

Sources: Centers for Disease Control and Prevention, World Health Organization

The Associate Press contributed to this report.

Download a printable version of this fact sheet here.

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