Various N95 respirators at a laboratory of 3M, in Maplewood, Minn., which has been contracted by the U.S. government to produce extra marks in response to the country's coronavirus outbreak. (Reuters/Nicholas Pfosi)

A shortage of specialized masks has prompted federal health officials to loosen their recommendations on the face protection that front line health-care workers should use to prevent infection from the highly contagious disease caused by the novel coronavirus.

Instead of recommending that health-care workers use specialized masks known as N95 respirators, which filter out about 95 percent of airborne particles, the Centers for Disease Control and Prevention posted new guidelines Tuesday that said “the supply chain of respirators cannot meet demand” and that looser fitting surgical face masks “are an acceptable alternative."

The more commonly worn surgical masks will limit — but not eliminate — the chance of inhaling large, infectious particles circulating near the face. Until Tuesday, the CDC had recommended that health-care workers interacting with coronavirus patients or suspected cases wear N95 respirators, along with gowns, gloves and eye protectors. The N95 filters must be custom-fitted and cost more than surgical masks.

The CDC guidance has been in discussion for days, and more than a dozen unions had previously said they were opposed to any changes in recommendations because emerging diseases like covid-19 pose an occupational hazard for workers on the front lines, especially health-care workers.

“We are strongly opposed to any measures that fail to provide optimal protection and infection control standards,” they wrote in a March 6 letter to CDC officials. The unions include National Nurses United, the American Federation of Teachers, and the Transport Workers Union of America. “Now is the time to use every possible tool available to guarantee the highest level of protection, guided by the precautionary principle, to prevent further spread of infection, protect healthcare workers, and preserve our capacity to respond to a widespread outbreak.”

Medical face masks are often used during flu season or a virus outbreak. Demand for masks has skyrocketed amid the coronavirus outbreak. (Video: The Washington Post)

The CDC guidance said the changes were prompted by the shortages. Surgical face masks will block the respiratory droplets produced by patients who cough or sneeze, which is the primary way the virus is spread.

The CDC is recommending that N95 respirators be reserved for protecting workers in the riskiest situations, where fine aerosol is likely to be generated. These include certain medical procedures like intubation, which helps a severely ill patient breathe. CDC’s guidelines also recommend that health-care facilities consider alternatives to the N95 masks, such as more elaborate (and expensive) powered air purifying respirators.

“I recognize that individual facilities may face shortages of certain types of personal protective equipment, including N95 respirators, but there is no evidence that surgical masks are adequate to prevent exposure of frontline health care workers to the virus that causes covid-19. CDC should prioritize conserving equipment and systematically addressing any shortages as they occur, instead of placing every health care worker at increased risk,” said Rep. Robert Scott, D-Va., who chairs the House committee on Education and Labor.

During the height of flu season over the course of four years, researchers studied flu-infection rates among health care workers at seven U.S. medical centers. Some workers were randomly assigned to wear N95 respirators and others surgical masks. The two groups showed no significant difference in flu infection rates, according to the study, which was published in September in JAMA, the Journal of the American Medical Association.

The government’s response to the coronavirus outbreak in the United States has highlighted one of the country’s biggest gaps in preparedness for battling the respiratory virus that causes covid-19. The United States has about 1 percent of the 3.5 billion respirators that experts estimate the health-care system needs a year to fight a severe influenza pandemic. That translates to 12 million N95 respirators and 30 million surgical masks, Health and Human Services Secretary Alex Azar has said. An additional 5 million N95 respirators may be expired, he has said.

State and local officials rely on a federal stockpile, known as the Strategic National Stockpile, for public health emergencies. But the federal government has not maintained the more than 1,000 items at the fullest levels in the stockpile. Biodefense experts blame bureaucracy and a lack of funding. Experts have also disagreed on the best way to replenish items because many supplies, including masks, have limited shelf lives. N95 masks last between five to six years, experts say, before their elastic and fibers degrade.

Federal health officials have announced plans to buy 500 million N95 respirators over the next 18 months for the stockpile, “part of a broader effort to maximize the availability of personal protective equipment for health care workers who are on the front lines” fighting spread of the virus.

At a briefing of the coronavirus task force Tuesday, Vice President Pence said the administration favors legislation that “would extend temporary liability protections, so [N95] masks made for industrial use could be sold so hospital workers could be protected.” Pence said such a measure would “make more N95 masks available.”

Emma Brown, Beth Reinhard and Amy Goldstein contributed to this report.

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