Federal health agencies are making more respirators available to care providers as demand grows and coronavirus cases continue to escalate nationwide.

On Monday, the Food and Drug Administration authorized emergency use of respirators that are normally approved only by the National Institute for Occupational Safety and Health for industrial use. These small-particle filtering masks currently account for most respirators on the market, and can help meet the needs of healthcare workers during the outbreak, the agency said.

The newly authorized respirators include N95s and other personal respiratory devices designed to fit closely to the face. When worn as recommended, they can help filter up to 95% of very small airborne and liquid particles. The FDA’s Emergency Use Authorization page provides a link to a downloadable list of the NIOSH-approved respirators. 

While federal agencies reported no sign of respirator shortages at the time of the emergency authorization announcement, concerns about availability have since risen. A Health and Human Services official on Tuesday estimated that the U.S. can fulfill only 10% of the respirator masks needed by healthcare providers in the event of an pandemic-level outbreak, according to a CNBC report.

The FDA and the Centers for Disease Control and Prevention recommend that respiratory masks be worn by healthcare workers in healthcare settings, and not by the general public.