Decontamination refers to the process of sterilizing masks by decreasing the number of bacteria and/or viruses on used masks and is of vital importance. Decontaminating your disposable masks ensures that you are reducing the risk of self-contamination from any of the pathogens which may linger, especially after you have used them.

Decontaminating disposable, single-use masks and respirators

Here are some tips on what can be done in a situation where a disposable respirator must be reused:

There are no guaranteed methods of decontamination that can be done in the home to immediately sterilize a single-use masks or filtering facepiece respirator (FFRs). The respirators are generally intended for single-use; therefore, decontamination of single-use respirators might reduce their efficiency. The safest methods, without professional equipment, all involve leaving a mask or respirator in a sterile environment for a minimum of 7-14 days at room temperature (22°C/71.6°F, 40-65% humidity), so that bacteria and viruses can die off.

  • Leave the mask or respirator in a closed, non-airtight container or paperbag long enough for the viral particles to die-off (depending on room ambience, 7-14 days should suffice).

  • While this recommendation is not definitive, leaving the mask or respirator in direct sunlight (for UV sterilization) for 24 hours might decontaminate your mask. It is important to know that the UV exposure would not penetrate to all areas of your mask. This should be seen as a last resort, once exhausting the other options for decontaminating your mask.

  • Recent preliminary research also suggests that masks and FFRs could be decontaminated for reuse via dry heat in an electric cooker, such as a rice cooker or an Instant Pot. It is recommended that:

      • Cooking cycles should reach 100°C/212°F for 50 minutes
      • No water should be added to the cooker (dry heat)
      • A small towel should cover the bottom of the cooker to prevent direct contact of the heating element with the mask or FFR.

Note: If the mask or respirator was splattered with other contaminants that could lead to bacterial growth, wipe it down to remove bacteria before leaving it out for the viruses to decay. This is why it is recommended for fabric masks to be machine-washed at high temperatures between uses. Paper masks like disposable surgical masks, FFRs and others that cannot handle machine washing or water are more challenging to sterilize. While the virus is dying, bacteria may grow from saliva, bodily fluids, food and drink that got onto the mask, and some types of makeup. Getting the mask “clean” first is helpful.