Decontaminating Covid-19 Masks Raises Safety, Efficacy Concerns

As coronavirus infections rise and N95 masks to protect health-care workers remain in short supply at least until the fall, many are decontaminating and reusing the masks that are designed to be used once.

The use of decontaminated masks has raised safety concerns among nurses, but mask manufacturers such as 3M Co., and government agencies, such as the Occupational Safety and Health Administration, say the sterilized masks are safe, although they’d prefer new ones to be worn.

“We’ve seen a rush to embrace these decontamination processes,” said Jane Thomason, lead industrial hygienist for National Nurses United. “They’ve not been ...