The U.S. Centers for Disease Control and Prevention revised earlier guidelines that had discouraged the use of gold-standard N95 masks in new guidance published Friday. The agency had earlier suggested reserving such masks for medical personnel. 

Health officials are looking for ways to limit the spread of omicron, which preferentially targets the upper airways and has spread at least twice as quickly as delta. The agency recently relaxed Covid-19 guidelines to say that people can leave isolation five days after their symptoms stop if they wear masks in public for an additional five days. 

The agency continues to recommend that people age 2 and older, regardless of vaccination status, wear well-fitting masks while indoors in public spaces, and stresses that any mask is better than no mask. 

While N95 masks aren’t in shortage at most facilities, supplies remain fragile, said Blair Childs, a spokesperson for Premier Inc., a top health-care and hospital supplier. Encouraging their use more widely could promoted hoarding and counterfeiting, Childs said.  

“While well intentioned,” Childs said in a statement, “proposals to provide N95 masks to all Americans in a compressed period of time is misguided and has the potential to throw the health-care supply chain into disarray.”

The highest grade surgical N95 respirators should be reserved for health-care personnel, according to a statement from the Infectious Diseases Society of America, but regular, non-surgical N95 masks are appropriate for public use, particularly in settings where the risk of spread is high. 

Speculation about the update earlier this week contributed to a surge in prices for N95, considered the gold standard, and KN95 face coverings on sites like Amazon.com. Worried consumers abandoned their simple cloth or surgical masks in search for something more protective.

Meanwhile, Covid-19 cases are continuing to climb across the country, threatening to upend the lives of workers and students who are infected or exposed to the virus. Health officials have been encouraging all adults to get booster doses.

CDC also issued new standards that will grade masks as being “workplace performance” and “workplace performance plus.” The standards are based on masks’ filtration, breathability and leakage ratio, and masks will be labeled for authenticity, the agency said.