Contamination during reuse of N95 masks

Editor's Note

This simulation study, led by researchers at the Louis Stokes Cleveland VA Medical Center, Cleveland, finds that reuse of N95 masks can result in contamination of those wearing the masks and the environment, even when correct technique is used.

A total of 12 healthcare workers (HCWs) performed 3 simulated examinations with mannequins, including (1) control with suboptimal N95 handling technique, (2) improved technique with glove changes after each N95 contact, and (3) control with 1-minute ultraviolet light treatment.

Included in the findings:

• Group 1 with suboptimal N95 handling technique frequently transferred the benign study virus to other participants, the mannequin patient, and environmental surfaces and fomites.
• Group 2 with glove changes after N95 contact had a significantly reduced transfer of the study virus.
• Group 3 with ultraviolet treated N95s had reduced transfer in both higher- and lower-inoculum simulations.

Simulations with fluorescent lotion demonstrated multiple potential routes of transfer to participants, mannequin, and surfaces, including direct contact with the contaminated N95 masks and indirect contact with contaminated gloves.

The researchers concluded that reuse of N95 masks can result in contamination of personnel and the environment, even when correct technique is used. Decontamination with ultraviolet light could reduce the risk for transmission.