Researchers have been investigating the stability of the novel coronavirus on different surfaces to try and figure out how it can be transmitted.

A new report published in the journal Lancet found the virus lasted on the outside of a surgical mask for 7 days.

The study reinforced existing recommendations for people to not touch the outside of their masks after putting them on.

Researchers also doubled down on previous precautionary measures that washing your hands frequently, avoiding touching your face, and staying home are the best ways to protect yourself from COVID-19.

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Since the early days of the coronavirus outbreak, researchers have been studying how long it can live on various surfaces, from cardboard to stainless steel.

The novel coronavirus is primarily a respiratory illness and is believed to spread via droplets from an infected person's coughs or sneezes. It might also be transmitted on objects if you grab something that has enough virus particles on it then touch your face.

This growing body of research has been used to help guide recommendations on how the public can protect themselves from COVID-19.

A new report published in Lancet studied the stability and amount of virus present over time on various surfaces, including tissues, wood, and cloth.

They were surprised to find the novel coronavirus on the outside of a face mask a week later. It's worth noting that the researchers didn't study whether someone could be infected with the virus they found on the mask.

"Strikingly, a detectable level of infectious virus could still be present on the outer layer of a surgical mask on day 7," the researchers wrote.

Face masks, particularly surgical masks and N95 respiratory masks, have been in high demand — and short supply —since the outbreak.

After the White House recommended that all Americans wear face coverings in public, officials are increasingly suggesting that people craft their own out of scarves, bandanas, or T-shirts to save face masks for medical workers on the frontlines battling COVID-19.

There isn't much scientific evidence that masks help prevent infection from spreading in a population, except when you put them on the people who are already sick, Business Insider's Hilary Brueck explained.

But a fair number of COVID-19 patients could be either asymptomatic or presymptomatic and still transmit the virus to others. For this reason, the CDC is now recommending people cover their faces when out in public spaces, like the grocery store, to prevent unknowingly infecting others.

Scientists are in consensus that staying home and social distancing as much as possible are the best ways to decrease the number of infections and "flatten the curve."

Properly wearing and taking off face masks is key

The researchers, including Leo Poon Lit-man and Malik Peiris, said their findings show how important it is to properly wear and remove masks.

"This is exactly why it is very important if you are wearing a surgical mask you don't touch the outside of the mask," Peiris told the South China Morning Post. "Because you can contaminate your hands, and if you touch your eyes you could be transferring the virus to your eyes."

The CDC recommends wearing a snug, cloth face covering that goes over your mouth and nose, and that you wash it frequently in a washing machine. When you take it off, avoid touching the front of the mask where it's dirtiest, and wash your hands directly after.

Wash your hands with soap and water

The research team, which included scientists from the National Institute of Allergy and Infectious Diseases and the US Centers for Disease Control and Prevention, also found that the coronavirus was more stable on smooth surfaces. Previous research found that the coronavirus can live on copper for 4 hours, on cardboard for 24 hours, and on plastic for three days — but the lifespan of the coronavirus is also impacted by various factors such as temperature and humidity.

That's why officials recommend regularly disinfecting household objects that people touch often, such as doorknobs, countertops, and phones.

For those worried about carrying viral particles while getting groceries or other essential items from the store, Poon said you should leave non-perishable items in their shopping bags for a day before handling them again.

"That would reduce the viral titre [concentration] a lot," he added.

Poon also doubled down on existing recommendations that washing your hands with soap is one of the best ways to protect yourself.

"If you want to protect yourself just maintain good hygiene, wash your hands often and try not to touch your face, your mouth, or nose without cleaning first," Poon told the South China Morning Post.