FDA Says It Won't Object to Dry Heat Use on N95 Respirators

Alicia Ault

November 30, 2020

Editor's note: Find the latest COVID-19 news and guidance in Medscape's Coronavirus Resource Center.

The US Food and Drug Administration (FDA) says it will not object to hospitals or other entities using unapproved dry heat systems to "reduce the bioburden" on N95 respirators that are intended for reuse by a single person.

In releasing its new guidance, the agency explicitly acknowledged the desperate measures being taken to conserve personal protective equipment during the surging COVID-19 pandemic.

The new FDA policy applies to respirators that

  • are FDA approved;

  • have received emergency use authorization (EUA) by the FDA for CDC's National Institute for Occupational Safety and Health (NIOSH)–approved filtering facepiece respirators (FFRs);

  • have received EUA by the FDA for imported, non-NIOSH-approved FFRs that are not manufactured in China;

  • do not have exhalation valves;

  • do not incorporate a duck-bill design;

  • do not contain antimicrobial/antiviral agents.

"Today's guidance is another example of how FDA is working to address critical shortages in personal protective equipment and help protect health care personnel during the COVID-19 public health emergency," said Binita Ashar, MD, director of the Division of Surgical Devices in FDA's Center for Devices and Radiological Health, in a statement.

Unproven, but Sufficient?

Dry heat systems are being used to decontaminate N95 masks, but FDA has not issued an EUA or given full approval to any such device. The devices have not been proven to be effective, but the heat might reduce the amount of microorganisms present, said the agency.

Ashar said the evidence is sufficient to demonstrate "there is a reduction of microbial load on certain respirators when exposed to certain dry heat parameters."

The agency said that as of November 25, "the FDA does not intend to object to the use of certain dry heat systems for the purpose of reducing bioburden and supporting single-user reuse of otherwise disposable FFRs."

The FDA said manufacturers should follow its new recommendations on system settings and labeling. Users and manufacturers should also follow the Centers for Disease Control and Prevention's (CDC's) recommendations for reuse of respirators. The CDC advises, for instance, that the N95 be stored in a breathable paper bag for at least 5 days between each use and that it be worn a maximum of five times.

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