Thanks, Jon for the posting the latest info about mask decontamination. There was a study done in Japan in 2006 for the first SARS virus (link below) , and it found that UV-C treatment failed to completely inactivate the virus and a small amount remained viable even after extended treatment. It appears the study you linked to uses much higher doses of UV-C, but that could compromise the masks physically. UV-C will deteriorates elastic quickly, not to mention the extreme danger to eyes. Anyone attempting to use UV_C for sterilization should use a safety interlock system to cut power off if a door is opened or a lid is lifted. With the exception of quartz, most glass and poly-carbonate materials will (at least partially) block UV-c wavelengths, so those should not be used as an interface between the light source and the item being sterilized, bit don't count them to protect your eyes.
I saw your comment about the CDC changing their mind about recommendations on the use of face masks a week or two ago and I have been holding off on commenting. I am in the camp that if your are going to wear something to protect yourself, then do it right. But, I do believe that wearing anything will help slow down the spread to others.
What changes is that I did have to venture to the store a few times since then and given the current environment, certain things stand out more readily. Covid pandemic or not, some of the things I have seen makes me want to wash everything I bring home before putting in my fridge or pantry. There are a multitude of people of have no qualms about touching their noses or mouth (like licking their fingers before picking up a shopping bag), or even sneezing in their hand and continue touching things. One notable example was a person wearing a mask at the grocery store apparently needed to rub his nose. He did so by lifting the mask and sticking both index fingers into his nostrils simultaneously and proceeded to rub vigorously. He continued to shop and touch items with sanitizing hands. I guess if you are going to get infected, might as well give the virus a head-start and make sure it's well seated into the nasal cavity I've seen a multitude of workers who wear their mask over the mouth but not the nose, or just over the chin. I have seen a good number who tie the mask with top strap alone, and let the mask dangle over their nose, looking more like a belly dancer than one worried about keeping the virus at bay.
Lastly, I cannot begin to count the number of people I see wearing a mask over a thick beard. Back when I worked in industrial hygiene, wearing a mask over a beard was a no-no. trying to get a mask to have good fit even with stubble was near impossible. I suppose they are not going to protect themselves in any way, but it will shorten the distance the virus spreads.
Speaking of virus spread, the latest scientific recommendations recommend at least 10ft distance.
(stepping down from the soap box)