Research on best ways to sterilize masks

With the shortage of masks — particularly the N95 masks needed for the health workers who are putting their lives on the line — there has been considerable research when it comes to sterilization.

The research is particularly important for those health workers faced with having to reuse N95 masks. And of course people will obviously be re-using their fabric masks as well.

When it comes to the sterilization of fabric masks, there’s really no research on the subject, so in a public setting, they obviously need to be kept as clean as possible and will provide protection. But for health workers, they should only be used as a last resort and just once if possible.

As far as N95 masks, the University of Manitoba has done encouraging research. The university tested four types of N95 masks and four methods of sterilization. They identified techniques that may allow N95 masks to be sterilized up to 10 times.

Among the sterilization techniques was vaporized hydrogen peroxide, which a Duke University study also found effective. But vaporized hydrogen peroxide is widely available in North America.

But the technique that showed masks may be sterilized up to 10 times was autoclaving using medical autoclaves which are basically steam sterilizers.

High temperature steam sterilization alcohol washing, bleach washing, and ETO are methods that have been used but have also been shown to degrade these types of respirator masks such as N95 masks.

When it comes to sterilizing N95 masks for reuse, there doesn’t seem to be a full-proof solution, but disinfecting through warm, humid heat has been found to be effective.

When it comes to the reuse of N95 masks, five requirements must be met:

N95 mask reuse, there are a number of key factors to consider. At the completion of any process, the mask must:

They must retain filtration efficiency of 95 percent; maintain breathability;not have visible damage to the filter, straps or sealing members; bu successful decontaminated; and be safe to wear.

The Centers for Disease Control also have the following websites on guidelines when it comes to the use and sterlization of personal protective equipment, PPE:

https://www.cdc.gov/ coronavirus/2019-ncov/ hcp/ppe-strategy/facemasks.html https://www. cdc.gov/infectioncontrol/ guidelines/disinfection/index.html

https://www.cdc.gov/ niosh/topics/hcwcontrols/ recommendedguidanceextuse.html