Face masks could provide coronavirus protection. But there’s a ‘but’

California officials said covering your face could prevent you from becoming infected with the new coronavirus or from spreading it to others, but they stressed it should not be a substitute for social distancing, hand washing and other measures.

The guidance comes amid a new push in some quarters for people to wear face protection when shopping, going to medical appointments and doing other essential business.

“Face coverings could provide some additional protection against COVID-19, but Californians should not have a false sense of security if they choose to wear them. Make sure you’re also staying 6 feet away from other people if you have to leave your home to get groceries or prescriptions,” said California Health and Human Services Secretary Dr. Mark Ghaly, in a statement.

State officials have said people should not use medical and surgical masks, which are desperately needed by medical personnel.

“Face coverings are not a substitute for physical distancing or frequent hand washing, which we know are amongst the most effective ways to reduce the spread of COVID-19,” added Dr. Sonia Angell, director of the California Department of Public Health. “Wearing a cloth face covering could provide some additional benefit by acting as a reminder for other people to keep their distance, and it could help reduce the spread of infectious particles from those who could be infected but don’t have symptoms.”

The Centers for Disease Control and Prevention has argued that healthy people do not need a mask if they are not working in healthcare or caring for an infected person. But in recent days, the CDC has been weighing whether to modify its recommendations and endorse the use of homemade masks.

“I can tell you that the data and this issue of whether it’s going to contribute [to prevention] is being aggressively reviewed as we speak,” CDC director Dr. Robert Redfield told NPR.

Riverside County health officials released the new mask guidance Tuesday, covering such essential tasks as grocery shopping and medical visits.

“The face coverings do not have to be hospital grade but need to cover the nose and mouth. For example, bandannas, fabric masks and neck gaiters are acceptable. Fabric covers and bandannas can be washed and used again,” the county’s statement said.

Officials said the recommendation is based on new knowledge about the coronavirus.

“When the situation changes, the rulebook changes,” Dr. Cameron Kaiser, Riverside County’s public health officer, said in a statement. “We’re seeing our numbers increasing even sooner than we predicted, and that means our strategy must change too.”

At a Wednesday afternoon news briefing, Los Angeles Mayor Eric Garcetti said he had been awaiting advice on masks from the CDC but, with the COVID-19 rate surging, had decided to wait no longer.

The mayor said everyone performing essential tasks such as food shopping should wear homemade, nonmedical face coverings, or even bandannas, as people in other countries have done.

“To be clear, you should still stay at home. This isn’t an excuse to suddenly all go out,” Garcetti said.

He added that people shouldn’t use medical-grade masks, which are in short supply and are needed by healthcare workers and first responders.

Some experts say there are times when wearing a surgical mask, homemade face covering or bandanna might be a good idea.

Chunhuei Chi, director of the Center for Global Health at Oregon State University, noted that in Taiwan, people are required to wear surgical masks in places such as schools and restaurants and while riding public transportation.

Although surgical and homemade masks don’t filter out particles as effectively as N95 masks, they can still be useful, Chi said.

He recommends wearing a mask only if you have to be in close contact with people, such as riding a crowded bus.

The Associated Press contributed to this report.