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Electric cooker an easy, efficient way to sanitize N95 masks, study finds

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Re: Electric cooker an easy, efficient way to sanitize N95 masks, study finds

#121

Post by trehalose »

Jerry2 wrote: post #54

My family has been decontaminating our N95 masks with ozone. I bought a battery-operated O3 generator and if you place it into a tupperware container along with the mask, it will decontaminate it and then you can use it the next day. Yale School of Medicine has done a study on the efficacy of this method. [1] I prefer this method because it doesn't degrade the mask at all, it needs no disinfecting/harsh chemicals, it…

Ozone is an extremely harsh disinfectant chemical, and it's dangerous to say it's not. Various regulatory agencies in the USA set prolonged exposure limits at about 0.1ppm. [1] The USA's National Institute for Occupational Safety and Health has set its Immediately Dangerous to Life and Health (IDLH) concentration for ozone as 5ppm.

This study you've linked examines the disinfectant power (against Pseudomonas aeruginosa) of ozone at a concentration of 400ppm. If somebody who's been told that ozone is not a harsh chemical decides to open that airtight container and smell the sanitation, they might get a whiff of ozone so concentrated that doctors around the world will be talking about the resulting injury.

Even if you're careful not to do that, opening the container may cause a significant and harmful elevation of ozone concentration in the room if this is done indoors.

[1] https://www.epa.gov/indoor-air-quality-iaq/ozone-generators-...

[2] https://www.cdc.gov/niosh/idlh/10028156.html

Re: Electric cooker an easy, efficient way to sanitize N95 masks, study finds

#122

Post by weaksauce »

masklinn wrote: post #104
weaksauce wrote: post #56

Earlier quoted context omitted.

the cheap rice cookers use a temperature switch that triggers after it reaches a bit over 100C yes.

What do more expensive cookers use? A timer sounds more simplistic than a temperature sensor, are they mixing the temperature information with something else?

they use some more advanced logic than just on or off until it boils off the water

https://lifehacker.com/why-some-rice-cookers-are-20-and-othe...

Re: Electric cooker an easy, efficient way to sanitize N95 masks, study finds

#123

Post by wrycoder »

klyrs wrote: post #40
wrycoder wrote: post #35

Earlier quoted context omitted.

How do you know this?

https://smartairfilters.com/en/blog/sanitizing-masks-with-al...

Thanks very much for that link (and the links contained in it.)

I'm using 75% ethanol in a spray to "sterilize" (for SARS2 only, it's a fragile virus).

Even if the efficiency drops after spraying (which is not the same as soaking), I think it's still better than just a cloth or surgical mask.

The link to making high efficiency masks

https://groups.oist.jp/nnp/diy-face-mask

in the link you provided is quite interesting. The concept of HV electrostatic blowing of polyethylene is new to me - I wondered how N95 masks were made. I note that in the cotton candy machine experiments they reduced the voltage to 50V, lol.

I'm going to reserve judgement on the physics behind making electrostatically charged fibers and the question of how long they retain the charge. That's an interesting area to investigate! For example:

https://www.tandfonline.com/doi/abs/10.1080/00022470.1974.10...

Ethanol and isopropyl alcohol don't dissolve polypropylene, so the efficiency loss must be due to some other effect.

If the small fibers in the N95 mask have charge embedded in manufacturing, i.e. they are electrets, perhaps the removal of surface charge by alcohol (or screening by adsorbed alcohol?) is only temporary, and if the masks were tested a couple of days later, perhaps their efficiency might have recovered?

https://search.proquest.com/docview/236317922

I would appreciate it if the Federal administration put some effort into upping production of N95 masks for everyone - I've used them for years as dust masks, and now they are not readily obtainable. I still have a small stash, which we reuse and spray down with Everclear 151 after use.

Re: Electric cooker an easy, efficient way to sanitize N95 masks, study finds

#125

Post by [deleted] »

trehalose wrote: post #121
Jerry2 wrote: post #54

My family has been decontaminating our N95 masks with ozone. I bought a battery-operated O3 generator and if you place it into a tupperware container along with the mask, it will decontaminate it and then you can use it the next day. Yale School of Medicine has done a study on the efficacy of this method. [1] I prefer this method because it doesn't degrade the mask at all, it needs no disinfecting/harsh chemicals, it…

Ozone is an extremely harsh disinfectant chemical, and it's dangerous to say it's not. Various regulatory agencies in the USA set prolonged exposure limits at about 0.1ppm. [1] The USA's National Institute for Occupational Safety and Health has set its Immediately Dangerous to Life and Health (IDLH) concentration for ozone as 5ppm. This study you've linked examines the disinfectant power (against Pseudomonas aerugino…

[deleted]

Re: Electric cooker an easy, efficient way to sanitize N95 masks, study finds

#126

Post by Someone »

Voliokis wrote: post #66
noelsusman wrote: post #61

Earlier quoted context omitted.

They're not widely available to non-medical buyers because they're still not easily attainable for medical buyers. N95s aren't the easiest thing to manufacturer, so ramping up production to fully satisfy current demand would require a significant investment in time and capital. Companies aren't going to do that without some certainty that they'll actually be able to sell enough of their extra production to cover the…

I don't understand why governments haven't made the contracts and guarantees to ensure increased global production over the long-term (not just for Covid-19). We're going to need a much higher rate of production for years to come, yet everybody keeps thinking "Next month! It'll all be over next month!". I'm tired of this shit, and I'm tired of governments thinking so short-sightedly. The EU alone could make a huge di…

“but they're so unwilling to actually effect positive change in the world by using their position as a unified region”

https://en.wikipedia.org/wiki/General_Data_Protection_Regula..., https://en.wikipedia.org/wiki/Restriction_of_Hazardous_Subst... (Both examples of https://en.wikipedia.org/wiki/Brussels_effect)

Thing is: if the long term necessity for increased production of N95 masks were a no-brainer, companies would commit to building facilities. If governments subsidized producers, and it turns out we end up with more masks then we need, people would accuse them of wasting taxpayer money. Making that call is hard, as companies are ramping up production and articles such as the one being discussed could mean much fewer masks are needed.

Also, it seems at least Germany is working on this. https://www.reuters.com/article/us-health-coronavirus-europe...:

“Germany has said it will foot 30% of the investment bill for companies that manage to get production of the coveted filter fabric started before year-end”

Re: Electric cooker an easy, efficient way to sanitize N95 masks, study finds

#127

Post by angry_octet »

angry_octet wrote: post #100
dboreham wrote: post #85

Earlier quoted context omitted.

Fwiw KN95 (Chinese standard) are available from Costco online for about $2.50 a piece. I assume Costco isn't selling fakes. They have ear loops so the fit isn't as tight as N95 masks and needs some fiddling.

Why would you assume that?

Because multiple governments have found themselves with millions of dollars of fake/noncompliant masks, and last I checked, Costco doesn't have a mask testing facility.

Re: Electric cooker an easy, efficient way to sanitize N95 masks, study finds

#128

Post by hatsunearu »

dboreham wrote: post #85
foobiekr wrote: post #57

Related: can anyone explain why there are still no n95 masks available? It seems like, a few months in, it's surprising that there are none available for non-medical buyers. Is this perception wrong?

Fwiw KN95 (Chinese standard) are available from Costco online for about $2.50 a piece. I assume Costco isn't selling fakes. They have ear loops so the fit isn't as tight as N95 masks and needs some fiddling.

KN94 is the Korean standard. They made their own because the need for a standard arose because of the dust that comes from China. Not sure what KN95 is.

Re: Electric cooker an easy, efficient way to sanitize N95 masks, study finds

#129

Post by sherbondy »

otterley wrote: post #111
sherbondy wrote: post #97

Earlier quoted context omitted.

My wife has been selling NIOSH-approved KN95 [1] masks to folks in the US for the past few months. First she tried to supply them directly to hospitals but ran into a harrowing amount of red tape. Then she listed them on eBay but got banned for “price gouging” despite listing at a lower rate than many of the approved sellers. Now she’s just selling the remaining inventory directly, and completely deterred from trying…

Are they really NIOSH approved? NIOSH doesn’t approve KN95 masks[1]. Also, I thought elastic straps have to go around the head instead of the ears to obtain approval. Can we see the approval certificate? [1] https://www.cdc.gov/niosh/npptl/usernotices/counterfeitResp....

You are right, I was mistaken, sorry for the misinformation! They went though the NIOSH modified testing protocol, not the official approval process.

They have been tested for respirator filter efficiency only and were found to exceed 99% filter efficiency: https://www.cdc.gov/niosh/npptl/respirators/testing/results/...

But they are explicitly not NIOSH approved and as mentioned have an ear loop design whereas seemingly all approved masks go around the head. Wish I could edit/remove the original posting.

Re: Electric cooker an easy, efficient way to sanitize N95 masks, study finds

#130

Post by taejo »

hatsunearu wrote: post #128
dboreham wrote: post #85

Earlier quoted context omitted.

Fwiw KN95 (Chinese standard) are available from Costco online for about $2.50 a piece. I assume Costco isn't selling fakes. They have ear loops so the fit isn't as tight as N95 masks and needs some fiddling.

KN94 is the Korean standard. They made their own because the need for a standard arose because of the dust that comes from China. Not sure what KN95 is.

KF94 is a Korean standard. KN95 is a Chinese standard.
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