Face masks have become a consistent recommendation among the world’s health organizations to slow the spread of COVID-19. Unfortunately, this has created a shortage in the supply of face masks and other PPE.
But with mask shortages, can you just keep reusing the masks you have? Can the coronavirus stay on a mask and infect you if you reuse it?
The answer is yes, the COVID-19 virus can stay on a mask for up to 7 days or more. So, if you do want to reuse a mask you either have to leave it in storage for that long or use another method to decontaminate it. The good news is that research has been done on the best methods of decontamination.
Face Mask Cleaning Criteria
3M, one of the world’s largest suppliers of N95 masks has come up with 4 criteria for good decontamination methods:
- Effective at killing the virus
- Does not damage the respirators filtration system
- Does not affect the mask’s fit
- Is safe for the person wearing it
Some methods of killing the virus, such as microwaving, can destroy the structure of the mask. Other methods, such as alcohol and bleach eliminate any static charge from the mask. The way the masks work requires static charge to attract virus particles into the fibres that make up the mask. Decontamination methods need to clean the mask and maintain the static charge.
At-Home Mask Cleaning Methods
The following mask cleaning methods might be safe if you are reusing masks at home for personal use. These methods are not Health Canada-approved and should never be used for medical masks or high-risk situations.
Hot water can be used to decontaminate masks. But there is a lengthy process to go through in order to re-establish electrostatic charge. The first step is to steep used masks in hot water at a temperature of over 56 degrees celsius for 30 minutes. In the second step the masks need to be dried with a hair dryer for 10 minutes. The last step is to rip up a piece of paper into small bits, then sprinkle these bets on to the mask. If the paper sticks, the charge of the mask has been restored and it can be reused.
Another simple way to decontaminate a mask is with heat. This method has not been tested as well as other methods and needs further study. Preliminary work suggests that baking at about 75 degrees Celsius for 30 minutes might allow for safe mask reuse. Again, this is not yet a standard method due to the lack of evidence.
The final simpler, and less proven, method of decontamination is with steam. It is commonly accepted that 30 minutes of pressurized steam at a temperature of 121 degrees Celsius kills almost all pathogens. However, this method also requires re-establishing a static charge after the steaming. There is also the potential for mold or other bacterial contamination of the mask if this is not done properly.
For industrial or healthcare settings, more robust and proven ways of decontaminating an N95 mask are needed. All of the following technologies are used in devices that have been approved by Health Canada for use against COVID-19. These techniques should only be used with a Health Canada-authorized device to prevent risk to health or safety.
UV Radiation Decontamination
Several studies have examined UV radiation and it has shown the ability to kill viral pathogens. One study found that 15 minutes of UV-C radiation is enough to kill the virus. The caveat is that the radiation has to be done correctly with certain standards met:
- An appropriate UV-C source must be used
- A dose of at least 1 J/cm2 needs to be validated with a sensor
- All areas of the mask must be disinfected including both sides and in folds where shadows could be created
Hydrogen Peroxide Decontamination
Hydrogen peroxide is a liquid (in its pure form) that can be used to clean face masks through a process called fumigation. Fumigation is when a contained space is vapourized with chemicals in order to kill pathogens inside the area.
Hydrogen peroxide has inactivated SARS-CoV-2 (the virus that leads to COVID-19) on all N95 mask types tested. It also kept leakage below 1.5% for up to 10 cycles, and it was equivalent to new masks after 1 cycle. Other advantages of hydrogen peroxide are:
- Inactivates highly-resistant bacterial spores
- Does not degrade N95 filter or strap quality after up to 20 cycles
Ozone is not as well-studied as the other technologies, but it is also powerful against SARS-CoV-2. One study showed that it killed more resistant pathogens than SARS-CoV-2 and it maintained respirator integrity.
State-of-the-Art Decontamination Technology is a Phone Call Away
You may be saying, “This is great, but I don’t have the technology to use UV, hydrogen peroxide or ozone on my masks.” This is where you’re wrong.
SteriRight uses the above-mentioned technologies to bring mobile face mask reprocessing and decontamination services to local businesses. The high-tech machines that SteriRight use combine UV-C, hydrogen peroxide and ozone to make compounds that kill highly-resistant pathogens, including the novel coronavirus.
Sanitizing face masks for reuse can save companies money, time and headaches trying to obtain new face masks during a time when there is a large shortage. It is also great for the environment because it means fewer masks going into landfills or even clogging up the sewage system.
Not only is this process effective and environmentally-friendly, but it’s extremely fast. SteriRight’s machine can sanitize hundreds of masks per hour. Masks are loaded into a tray that is placed on a conveyor belt. The entire process is completed in less than a minute.
So how do you access this great technology? Simply call SteriRight or fill out a contact form to set up a time for us to visit.
There are enough problems to deal with during this pandemic – trying to order new face masks during a shortage doesn’t need to be one of them.