Newswise — The U.S. Centers for Disease Control and Prevention (CDC) has revised its guidelines on face masks during the COVID-19 pandemic and is now recommending everyone voluntarily wear fabric or cloth coverings while in public to prevent spread of the virus.

There are some critical things to know about how to use a nonmedical mask correctly, because when used incorrectly, which is pretty easy to do, you could actually put yourself and others more at risk. Physicians at The University of Texas Health Science Center at Houston (UTHealth) break it all down.

  1. We are talking cloth masks, not surgical masks or N95s.

Surgical masks and N95s should still be reserved for health care workers only. They need them the most, as they are on the front lines caring for patients during this pandemic.

If you see a health care worker wearing a cloth mask, it is likely that they are wearing it over their personal protective equipment (PPE) in an effort to make the PPE last longer, said Hilary Fairbrother, MD, MPH, an emergency medicine physician with McGovern Medical School at UTHealth.

 If you have any unused surgical masks or N95s, consider donating them to your local hospital.

  1. Using a fabric covering is a supplement to social distancing guidelines, not a replacement.

Your best defense against COVID-19 is to practice social distancing, wash your hands frequently, and only leave your home for essential errands. According to the World Health Organization, the virus is spread through droplets. You’ve probably heard that a lot, but what does that mean? Michael Chang, MD, a pediatric infectious disease specialist with McGovern Medical School and UT Physicians, explains:

“At the most basic level, droplets are large infectious particles that will fall out of the air quickly, within minutes, due to gravity and weight from a higher moisture content. Airborne particles, called ‘droplet nuclei,’ are a smaller part of the droplet, and they can float in the air for hours or more. You have to be closer to someone, within six feet, to transmit a virus via larger droplets.

Many respiratory viruses, COVID-19 likely included, can infect you through multiple routes, including the nose, mouth, and eyes. The droplets can also survive for around 72 hours on surfaces, so when you touch a contaminated surface you can still bring the virus up to your face,” Chang said.

Wearing a cloth mask covers those key openings, so it could prevent any large droplets from entering. However, if you are properly social distancing while running only essential errands and washing your hands, that should be sufficient to prevent the spread of the virus. A cloth mask is most effective at keeping your germs in, rather than keeping others out.

  1. If you wear a cloth mask, do not touch it.

“What most people are just now starting to realize is how much stuff they touch in a day, followed by how many times they touch their faces,” Chang said.

Masks of any kind are uncomfortable and can cause you to touch your face more by constantly adjusting it. This can be problematic, as that is precisely how the virus would enter your body.  

“Once you touch the cloth part of the mask, you have to consider yourself contaminated and wash your hands immediately,” Fairbrother said. “If you must adjust it, only touch it by the strings or the ties in the back.”

Chang also notes that if someone touches the cloth part of their mask and then a surface, they could be leaving parts of the virus there for someone else to touch, inadvertently promoting spread. 

  1. Make sure the cloth mask covers your nose and mouth with a snug fit that does not touch your lips.

A tight fit with the mask covering the nose and the mouth, without many gaps, with a very fine material should help catch droplets, Chang said. However, the mask cannot be so tight that it touches your lips.

“If a cloth mask is touching your lips and droplets have saturated the fabric, droplets could then be directly entering your mouth,” Fairbrother said. “Try to wear one with a high thread count for added durability.”

Chang says the reverse is also true, where your droplets could spread through the mask to others.

“Depending on the fabric of the mask, you can imagine pressing the cloth mask up against your lips, nose, and eyes, with the moisture build-up from your breath, then transmitting the infectious agent through the mask,” Chang said.

  1. After you wear the cloth mask in public, wash it in hot water.

After wearing your cloth mask out and about, be careful with what you do when taking it off.

“It’s best to remove it by the strings and put it directly into the washer and then wash your hands,” Fairbrother said. “Wash it on a hot cycle to kill the germs. The other option is to put it in a bag and let it sit for 72 hours – that is the length of time studies are showing the virus can survive.” She has several cloth masks and rotates them so that a clean one is always available.

  1. No data or experience with COVID-19 in any other country points to cloth masks being successful on their own.

“When handled properly, the cloth mask is probably better than nothing, but there is no evidence that we can cite that shows they definitely work, or that they’re effective against COVID-19,” Chang said. “The probability that most people will be able to use a mask properly is low.”

“Furthermore, none of the countries that seem to have COVID-19 under control were using cloth masks as the only intervention. In China, extremely strict isolation measures were implemented. In South Korea, voluntary social distancing along with more per capita testing than any other country were likely major factors,” Chang said.

  1. If you are sick, stay home.

“Sick people still need to stay home and away from others. The cloth mask may catch the virus going out in large droplets, but if a sick person touches the mask while they’re out, it could all be useless,” Chang said. “Everyone wearing cloth masks will not be a panacea for the COVID-19 pandemic in the United States.”

How to make your own mask:

Directions from the CDC

Directions from the US Surgeon General