You should be able to use one many times without having to clean it using this donning/doffing/storage method.
This is the method my wife taught us all to use. I had one N95 for everyone in the house stashed away.
You should be able to use one many times without having to clean it using this donning/doffing/storage method.
Its not a money thing. Its a safety thing. Those masks are designed as one and done use. That being said, they can be cleaned but 3M cant guarantee there wont be any degradation in the masks effectiveness.....one could easily follow the money on that position. If more masks are cleaned and kept in circulation, then less masks need to be purchased. Competent medical entities have validated that these masks can be cleaned, with certain restrictions and caveats.
If you can get your hands on a far-UVC light, stick them in there for a while. No chemicals, no damage to the mask, and nothing but deactivated viruses. But, that is a big if as they are not widespread like regular UVC lights.
If you can get your hands on a far-UVC light, stick them in there for a while. No chemicals, no damage to the mask, and nothing but deactivated viruses. But, that is a big if as they are not widespread like regular UVC lights.
Alcohol works just fine cleaning the masks with no degradation to the masks.
UVC light breaks down the material the masks are made from.
This a great video explaining in depth different ways to clean and kill germs.
UV light is not recommended for use in sterilizing N95 masks.
Q3: Can the masks be treated using radiation or UV?
A: Radiation sources such as gamma rays or UV light are commonly used for the sterilization of materials, but they have the potential to degrade the PP material by the attacking the lone electrons pairs in the CH3 side group on the backbone of its molecular chains, leading to the dissipation of the charges. However, the degree of PP decomposition depends on the radiation and UV intensity as well as the exposure time. For example, PP will be totally degraded and become brittle after three months of exposure to sunlight during the summer. More experimentation is needed to determine the effect of ionizing radiation on the filtration efficiency of mask media at the duration and intensity needed to kill coronavirus.
The three web links below provide evidence of some small degree of strength loss but insignificant charge decay after UV sterilization at a certain dose and exposure time.
https://t.co/8aPfLMEskF?amp=1
https://pubmed.ncbi.nlm.nih.gov/25806411/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4699414/
The following link shows the loss of charges and strength after using gamma irradiation to sterilize the mask.
That is exactly the method being sold to hospitals and approved by the CDC though.
All these cleaning options are better than NO MASK! 50/50 is better than 0/0 Right?Alcohol should NOT be used in cleaning the N95 masks.
https://utrf.tennessee.edu/informat...tection-sterilization-of-face-mask-materials/
Q2: Can the masks be treated using alcohol?
A: No. Face masks cannot be sterilized using alcohol because the charges will be erased by either alcohol liquid or its vapor, as described above.
My colleague Dr. Cai, a retired filtration testing scientist, collected experimental data in February 2020, shown in the table below, that support my past results.
Table 1. Measured FE after treatment with alcohol and soap/water (Cai et al., Feb. 2020).
Treatment using alcohol or soap water FE
Initial filtration efficiency (3-fold medical mask) 93.2%
After immersion in medical alcohol 67.0%
After treatment with saturated IPA vapor (ISO) 47.4%
After washing by hand with soap/water for 2 minutes 54.0%
The first web link in Q3 shows similar charge decay results after sterilization using alcohol.