Important information: disinfection and sterilization of masks
NewsDisposable filter respirators (masks) are not decontaminated and are not intended for reuse. Today, however, the global Covid-19 pandemic has left people around the world facing a shortage of masks. They are vital tools for not being infected.
We will tell you about the most accessible methods of decontamination and disinfection of masks that allow them to be reused.
3 main types of disposable filter respirators:
- Surgical masks
- Elastomeric respirators
- N95 type respiratory masks
The mask can be considered ready for use if the following parameters are met:
1.Maintaining filtration efficiency >95%.
2. Safety of the filter and preservation of breathability.
3. No visible damage and deformation of the filter, belts and sealing elements.
4. Destruction of microorganisms (for example, SARS-Cov-2, which causes Covid-19).
5. Safety for the carrier (there should be no chemical residues and toxic gas emissions).
The disinfection cycle can be repeated until all 5 points are met.
Hydrogen peroxide vapor
Hydrogen peroxide vapor has long been used for industrial purposes for disinfection, but in the latest research from the University of Denmark, it has shown its effectiveness for viruses similar to SARS-CoV-2, while not damaging the N95 mask.
Heat and moisture
There is more and more evidence that inactivation of the SARS-CoV-2 virus is possible using heat and relative humidity.
Tests have shown that the exposure of the mask at t=65C and 85% humidity for 30 minutes ensures the destruction of >99% of influenza viruses. The CDC emphasizes that t=60C and 80% humidity is as effective as 65C and 85%. This ratio of temperature and humidity is possible in an incubator, a chamber, or an impermeable oven.
Microwave oven-DANGEROUS! DO NOT APPLY!!!
Plastic tanks with perforated surfaces are filled with 50 ml of water at room temperature (Fig. 4).The contaminated N95 mask is placed on top of the center of the unit and loaded into an industrial microwave oven, where it is irradiated for 2 minutes (1 minute on each side of the mask). This method allows you to destroy >99% of viruses. Note that the N95 masks have metal nose bridges that tend to melt the surrounding tissues when heated, making the masks unusable. Moreover, heating in a microwave oven can lead to ignition.
Ultraviolet radiation
UV lamps are used to clean dirty surfaces (t=15 minutes on each side of the mask). Using this method allows you to destroy >99% of the virus. For the inactivation of the pathogen, both the dose and the wavelength are important. Keep in mind that any part of the mask in the shade will not be disinfected. It is especially important to observe the same dose at each point of the mask (the further away the surface is, the lower the dose reaches it). Certain belt designs are prone to twisting, which can also prevent uniform radiation.
Take care of yourself and your loved ones!
