Ok, you have raised the issue of light, of radiation
Can a mask be cleansed in a microwave.
UF researchers soaked sponges and scrubbing pads in raw wastewater containing a witch’s brew of fecal bacteria, viruses, protozoan parasites and bacterial spores, including Bacillus cereus spores.
The researchers used an off-the-shelf microwave oven to zap the sponges and scrub pads for varying lengths of time, wringing them out and determining the microbial load of the water for each test. They compared their findings with water from control sponges and pads not placed in the microwave.
The results were unambiguous: Two minutes of microwaving on full power mode killed or inactivated more than 99 percent of all the living pathogens in the sponges and pads, although the Bacillus cereus spores required four minutes for total inactivation.
Bitton said the heat, rather than the microwave radiation, likely is what proves fatal to the pathogens. Because the microwave works by exciting water molecules, it is better to microwave wet rather than dry sponges or scrub pads, he said.
So yes, microwaving a mask should do a good job of disinfecting it, but it would need to be wetted first for the process to work.
The masks I used to use had a strip of soft metal embedded in the top edge for adjusting the fit around the nose, so I wouldn't put one of those in the microwave.
If the mask has elastic straps the microwave radiation could cause the rubber to become brittle, but how quickly I don't know. Might test some rubber bands to see.