4 ms·

It looks like CDC recommends to use them for ≤ 8 hours (continuous or intermittent) [0]. [0] https://www.cdc.gov/niosh/topics/hcwcontrols/recommendedguidanceex

by sndean 7y ago

It looks like CDC recommends to use them for ≤ 8 hours (continuous or intermittent) [0]. [0] https://www.cdc.gov/niosh/topics/hcwcontrols/recommendedguidanceextuse.html https://www.cdc.gov/niosh/topics/hcwcontrols/recommendedguid...

pbhjpbhj 7y ago
Presumably their effectiveness is reduced then, rather than negated. Aren't they just close bound fibres that form a filter?
- rolph 7y ago
  they may become fomitic , actually carrying aggregations of virions nestled in expectorated particles of mucous
- sndean 7y ago
  Yeah probably reduced, but it may be more to do with them becoming contaminated. The link points to a study saying > One study found that nurses averaged 25 touches per shift to their face, eyes, or N95 respirator during extended use. How problematic that touching is probably scales with how problematic your environment is. They're pretty sponge-like. Wearing a surgical mask over an N95 would help a lot. In a controlled biosafety level 3 lab, "single use" things are definitely the most common, where everything exposed to the outside world is destroyed after you're done. What's worn underneath is washed and you're forced to take a shower. So that's what you do if you know you're in a contaminated environment – not sure what I'd do in a public place.
  - sebazzz 7y ago
    > Yeah probably reduced, but it may be more to do with them becoming contaminated. How effective is the virus after the mask has been unused for a while (so "cold", like a doorknob or a desk)? If it is not, the mask should be good to go then, doesn't it?
    - samatman 7y ago
      I gather that it's too early in understanding COVID to have robust answers to this sort of question. I use a reusable mask, and honestly, I don't wash it very often. It's there mostly so if I absentmindedly touch my nose I don't actually touch my nose, and so I never remove it until I've thoroughly washed my hands.
    - mc32 7y ago
      No idea but some people (whose source I don’t know) say the virus can live on some surfaces to nine days. Guess one could use sterilants/disinfectants to accelerate that time dramatically.
      - ludwigvan 7y ago
        Coronavirus can persist up to 9 days on inanimate surfaces. 70% ethanol can disinfect the surface within 1 minute. Source: https://www.journalofhospitalinfection.com/article/S0195-6701(20)30046-3/fulltext https://www.journalofhospitalinfection.com/article/S0195-670...

by sndean 7y ago

pbhjpbhj 7y ago

Presumably their effectiveness is reduced then, rather than negated. Aren't they just close bound fibres that form a filter?

rolph 7y ago
they may become fomitic , actually carrying aggregations of virions nestled in expectorated particles of mucous
sndean 7y ago
Yeah probably reduced, but it may be more to do with them becoming contaminated. The link points to a study saying > One study found that nurses averaged 25 touches per shift to their face, eyes, or N95 respirator during extended use. How problematic that touching is probably scales with how problematic your environment is. They're pretty sponge-like. Wearing a surgical mask over an N95 would help a lot. In a controlled biosafety level 3 lab, "single use" things are definitely the most common, where everything exposed to the outside world is destroyed after you're done. What's worn underneath is washed and you're forced to take a shower. So that's what you do if you know you're in a contaminated environment – not sure what I'd do in a public place.
- sebazzz 7y ago
  > Yeah probably reduced, but it may be more to do with them becoming contaminated. How effective is the virus after the mask has been unused for a while (so "cold", like a doorknob or a desk)? If it is not, the mask should be good to go then, doesn't it?
  - samatman 7y ago
    I gather that it's too early in understanding COVID to have robust answers to this sort of question. I use a reusable mask, and honestly, I don't wash it very often. It's there mostly so if I absentmindedly touch my nose I don't actually touch my nose, and so I never remove it until I've thoroughly washed my hands.
  - mc32 7y ago
    No idea but some people (whose source I don’t know) say the virus can live on some surfaces to nine days. Guess one could use sterilants/disinfectants to accelerate that time dramatically.
    - ludwigvan 7y ago
      Coronavirus can persist up to 9 days on inanimate surfaces. 70% ethanol can disinfect the surface within 1 minute. Source: https://www.journalofhospitalinfection.com/article/S0195-6701(20)30046-3/fulltext https://www.journalofhospitalinfection.com/article/S0195-670...