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'Good enough' way to clean an O2 Curve respirator?

by Kenny1 min read16th Sep 20212 comments

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This is a maybe too specific question, but answers for any 'SARS-CoV-2-or-similar-mitigating' thing like masks or respirators (that can be cleaned and reused) would probably be helpful and are definitely welcome.

Here's the post that convinced me to buy one of these respirators:

I've used it many times now, but never regularly; at most maybe twice a week, for a few hours at a time.

But it's been a good while since I last used it, I want to document for myself how to clean it (the respirator, not one of the removable filters), and apparently the company that makes them has shutdown (and broken links to their support info).

I did find this: Frequently Asked Questions – O2 Canada, a defunct or never-setup Shopify site:

Can the O2 Curve be disinfected?

Yes. The O2 Curve can be sterilized and/or disinfected. The O2 Curve has undergone sterilization certification studies with High Power Labs in the US. The Curve was processed through multiple cycles of both Gravity Steam Sterilization (121 °C for 35 minutes and 15 minutes drying time), as well as STERRAD® 100 NX® vaporized hydrogen peroxide, assessed for any signs of damage or wear, then mask fit tested again (using a new filter) to ensure the Curve was still functioning as intended. The Curve passed again with a mask fit test score of 200+, with the minimum passing score being 100. The O2 Curve has also been tested in single cycle autoclave protocols including the SciCan Bravo™ V21, and the SciCan STATIM® 5000 G4. The O2 Curve has also not demonstrated any appreciable material defects after multiple cleanings with commercially available disinfection wipes, such as Oxivir® Tb or CaviWipes™.

The first of the "disinfectio wipes" mentioned seems to mainly use some kind of variant of hydrogen peroxide:

I would somewhat-weakly conclude that hydrogen peroxide, e.g. from a retail drug store, would work to clean (NOT 'disinfect') the respirator for repeat, and even regular, use.

What else would work? Bleach wipes? Rubbing alcohol?

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It's probably silicone with maybe a little pigment in it. If you just want to clean it, you can clean it with anything that won't degrade the silicone. And not very many things will degrade silicone. You will know if you've managed to damage it because it will stiffen, crack, weaken, glaze over, or otherwise show signs of not being OK. All you care about is that it's airtight.

Regular soap. Dish soap. White vinegar.

Isopropyl alcohol might swell it a bit. It shouldn't be a problem if you don't soak it in the stuff, don't leave it on there for ages, and give it a few mintues time to evaporate before you use it or stick it in a sealed container. It's pretty effective as a disinfectant.

The bleach might do some damage, although if you just did a quick wipe with a low concentration of it, it would probably take a lot of cleanings to noticeably degrade the seal or reduce the flexibility.

Dilute hydrogen peroxide is a slow and selective disinfectant, and not much of a cleaner at all except for things it chemically reacts with. It could theoretically attack the silicone, although I bet it would take a long time at 0.5 percent, and what you quote about their tests seems to match that.

Wipe it, rather than washing it (and wipe it one or two more times with water if you need to "rinse" off whatever you're cleaning with). Make sure it's dry before you put it away or put it back on. Don't get water or cleaners on the filters. The straps might be less tolerant of some cleaners than the body.

If you wanted to thoroughly disinfect it or sterilize it, you would have more things to worry about. Notably getting into the cracks and crevices. If I had to sterilize something like that ath ome, I'd probably wipe it down with IPA, try to pick any crud out of any crevices I could get at, and then pressure cook it on a rack. But I wouldn't do it very often. And I don't think there'd really be a reason to do it at all.

HOWEVER, filters, especially high-efficiency non-woven filters that let you breathe easily, have limited lifetimes. Without valves, you're exhaling through them and getting them damp, which will degrade them faster. The O2 Web page you linked to says to replace the filters every couple of weeks "for air pollution" (which I suspect means with working valves), and daily "in clinical settings".

So if you can't get new filters, cleaning the respirator is probably not your big problem.

Thanks!

I think I've ruined other silicone objects by soaking them in IPA (isopropyl alcohol, not the beer).

I think what I ended up doing was wiping the mask (the rim that touches my face) with a 'baby wipe' –sterilization seemed like overkill. A nurse I asked about this directed me to just use soap and water.

You're right that filters are now the limiting factor for me continuing to use the respirator. Thankfully, I only need to use it, at most, a few times a week, and I had the foresight to buy several replacement filters when I purchased the respirator.

I'll probably switch to the same masks most other people are wearing eventually.