Science: How N95 Masks Extend and Reuse

The supply of N95 masks may be in short supply during a widespread outbreak of infectious respiratory diseases. In this case, we can take some steps to prolong the use of masks or reuse to alleviate the shortage, while better protecting themselves.

Science: How N95 Masks Extend and Reuse

First, whether it can be reused. The answer is yes. The National Institute of Occupational Safety and Health (NIOSH) says N95 masks can be reused as long as they “maintain the integrity of their structure and function and the filter material is not physically damaged or soiled.” According to the Centers for Disease Control and Prevention (CDC), a study has found that masks can capture 99.8 percent of the virus that comes into contact with the mask, i.e., once the virus comes into contact with the mask, the virus is less likely to fall off the mask, and breathing through the mask does not cause the virus to fall off the mask fiber. Although 99.8% is not 100%, considering that the mask itself is only 95% efficient in filtering air, 95% of the filtration effect is considered to be adequately protective.

Second, to answer the most important concerns, do not use the mask before re-use. The answer is that no disinfection is required. But when wearing and removing the mask, it is best to use clean hands, gloves, or paper towels. This would make the mask largely free of contamination, as the main risk of mask contamination is hand rather than air. Attempting to disinfect a mask may damage its “structural and functional integrity” and is best not to do so.

NIOSH has specifically published the Guidelines for Extended Use and Restricted Reuse of N95 Masks in Medical Environments, which itself is for medical personnel, and here are some of the recommendations available to the general public for your reference. The recommended guidelines state that extended use is preferable to reuse because exposure to masks can be reduced, thereby reducing the risk of exposure to transmission. Taking the following steps to extend or reuse the N95 mask to avoid contact transmission, subject to hand cleaning practices and proper wear:

1。 Discard N95 masks contaminated with blood, respiratory or nasal secretions or other bodily fluids.

2。 After close contact with an infected person who requires preventive measures, discard the N95 mask.

3。 Between uses, hang the used mask in a designated storage area or place it in a clean, breathable container (e.g., paper bag). To minimize potential cross contamination, store the masks separately, avoid contact with each other, and clearly identify the person who uses the mask. Storage containers should be treated or cleaned regularly.

4。 Clean your hands with soap and water or alcoholic hand sanitizer before and after touching or adjusting the mask.

5。 Avoid touching the inside of the mask and, if you accidentally touch the inside of the mask, clean your hands as described above.

6。 When wearing a used N95 mask and performing a user seal check, use clean (non-sterile) gloves and discard the gloves after they are worn and adjusted.

7。 Discard masks that are visibly damaged or difficult to breathe.

The guidelines also state that when at least one user is contagious (symptomatic or asymptomatic), secondary contact may occur when at least one user is contagious (symptomatic or asymptomatic), so that an N95 mask can only be used by one wearer and should be avoided when using it again.

Finally, routine N95 is good for the average person, and medical N95 is designed to protect surgeons and nurses from splattered blood.

Appreciation: Dr. David Cragin, An Expert in Risk Management and Occupational Safety and Health Protection, Mercado Corporation, IPEM Teacher.

Source: IPEM