SARS CoV2 aka COVID-19: Disinfecting Masks with Chlorine Dioxide (ClO2)
See also With N95 and N100/P100 Particulate Respirator Masks in Short Supply, What Might Work to Disinfect / re-Use?.
Background information, from Wikipedia:
Chlorine dioxide is a chemical compound with the formula ClO2... that is an oxidizing agent, able to transfer oxygen to a variety of substrates, while gaining one or more electrons via oxidation-reduction (redox).
Potential hazards with chlorine dioxide include health concerns, explosiveness and fire ignition. It is commonly used as a bleach. Chlorine dioxide was discovered in 1811 and has been widely used for bleaching purposes in the paper industry, and for treatment of drinking water. More recent developments have extended its application into food processing, disinfection of premises and vehicles, mold eradication, air disinfection and odor control, treatment of swimming pools, dental applications, and wound cleansing.
Christopher C writes:
I’m glad that you have been thriving in the outback, as well as producing some gorgeous photographs. That last one of wind-driven snow over the Alabama Hills is quite extraordinary!
I was surprised at the negative reaction to your discussion of anything COVID-19 related on your site, but I suppose it’s to be expected in a “post-fact” world in which people have managed to politicize even the absolutely facts about a virus <sigh>. I will note that I saw this pandemic coming, and ordered twenty N95 masks for each of us back in mid-January, so I have a number sitting in boxes. There has been no local emergency in our county (just over 100 cases in a relatively rural population of 162K), so I haven’t needed to donate them to the local hospital, at least not yet. I know that you prefer N100, but if you or your family need a few 3M N95s, please let me know and I’ll be glad to send some out to you.
I had a long conversation about sterilizing masks with a engineering friend of mine, who is a brilliant MIT-trained engineer. At the moment, I’m only going out for groceries once a week, and so I can simply afford to set my mask aside after the grocery run (in a dedicated pyrex container in the garage), and let any possible virus inactivate on its own. I’ll note that I have adopted the garb of an American I read about in Wuhan, and wear a waterproof pair of rain pants, rain top, nitrile gloves and N95 respirator (with exhalation port) when I go out. The outer layers, and dedicated “virus” shoes stay in the garage, and so far it’s working fine.
My sister lives in Lisbon, Portugal, and she and her husband were joined by two of their college-age children for the quarantine. Unfortunately, while Paris (a student in Barcelona) was asymptomatic when he arrived, three days later it was clear that he had coronavirus, and in a small apartment, it was inevitable that all four would be infected. They have all subsequently recovered, but their symptoms were extremely different one to the other. The daughter hardly experienced any illness, P was fairly sick (as though with bad influenza), my sister in her mid-50) was fairly sick, and her husband, also mid-50s was very sick. At one point they thought he might need hospitalization, but in fact never did. Three of the four entirely lost their sense of smell and taste, but all are recovering that capacity. So, not a catastrophe, but no picnic either.
I realized that if things got worse here, or if I needed to wear a mask on successive days, I needed to find a way to sterilize a limited supply. My friend’s solution was chlorine dioxide, which is apparently a standard disinfectant. One can purchase the compound as a foil packet that sits in a small perforated plastic container, and slowly releases the chlorine as it reacts to humidity in the atmosphere. This is apparently a routine operation for people who put boats in storage and want to keep mildew at bay, and the disinfecting action is powerful enough to kill anthrax spores. I went ahead and purchased several packages of this compound, but haven’t felt the need to use it yet, and so am simply keeping it in reserve. In any case, I wanted you to know about it in case it proves useful to you, as Santa Clara county is clearly in a much tougher situation than Centre county.
... Battelle Labs is using a gas decontamination method for respirators. Battelle is located in Columbus, Ohio, and my grandfather (a scientist in high-temperature metallurgy) was one of the founding members, which is why both my mother, and I, were born there: https://www.battelle.org/newsroom/news-details/battelle-deploys-decontamination-system-for-reusing-n95-masks Battelle is using hydrogen peroxide in their system: https://inside.battelle.org/blog-details/covid-19-deploying-a-critical-new-ppe-decontamination-system
I don’t think there’s any danger beyond the obvious; don’t inhale the compound deeply, this stuff is not good for living things! NosGUARD SG Mildew Odor Control Bags Fast Release Formula are at https://www.starbrite.com/item/mdg-mildew-odor-control-fast-release.
DIGLLOYD: this appears to be an excellent way to disinfect a mask, though I wonder if it might oxidize other things, like the rubber of the mask seal. If you go this route, my advice in using it would be to open the container OUTDOORS so as to let the ClO2 rapidly dissipate and keep hands and face away while doing so.