Technically, the best protection is a self-contained breathing apparatus (SCBA) which is a fancy way of referring to a respirator connected to an oxygen tank, but that thing too impractical and overkill for most people.
The amount of protection offered by a positive air pressure respirator (PAPR) depends on what kind of hood is being used and may offer about the same (or more) protection than a reusable elastomeric respirator. Assigned Protection Factor (APF) is a measure of the level of protection offered by types of respirators; PAPRs range from 25 to 1,000 APF, whereas reusable elastomeric respirators offer an APF of 10 (probably around 25 in reality) for half-facepiece respirators and 50 for full-facepiece respirators. Besides a potentially higher APF of 1,000, PAPRs also don’t require a fit test (which most people aren’t going to bother doing), so leaks are less likely, even though the APF might be similar or even less than a full-facepiece respirator. They’re also more comfortable than any other respirator. However, one hard-to-avoid disadvantage of a PAPR is that you’ll have to carry around an elastomeric respirator as a backup.
To mitigate the cost and bulk issues, it’s possible to DIY a PAPR (a plastic bag connected to filters, fans, and a battery). A DIY PAPR might be easier to repair and could also filter exhaust air, unlike commercial PAPRs. I haven’t bothered to DIY it yet, but others have definitely used these things successfully.
Technically, the best protection is a self-contained breathing apparatus (SCBA) which is a fancy way of referring to a respirator connected to an oxygen tank, but that thing too impractical and overkill for most people.
The amount of protection offered by a positive air pressure respirator (PAPR) depends on what kind of hood is being used and may offer about the same (or more) protection than a reusable elastomeric respirator. Assigned Protection Factor (APF) is a measure of the level of protection offered by types of respirators; PAPRs range from 25 to 1,000 APF, whereas reusable elastomeric respirators offer an APF of 10 (probably around 25 in reality) for half-facepiece respirators and 50 for full-facepiece respirators. Besides a potentially higher APF of 1,000, PAPRs also don’t require a fit test (which most people aren’t going to bother doing), so leaks are less likely, even though the APF might be similar or even less than a full-facepiece respirator. They’re also more comfortable than any other respirator. However, one hard-to-avoid disadvantage of a PAPR is that you’ll have to carry around an elastomeric respirator as a backup.
To mitigate the cost and bulk issues, it’s possible to DIY a PAPR (a plastic bag connected to filters, fans, and a battery). A DIY PAPR might be easier to repair and could also filter exhaust air, unlike commercial PAPRs. I haven’t bothered to DIY it yet, but others have definitely used these things successfully.
DIY PAPR intro info
https://viralhelmets.medium.com/15-viral-helmet-version-of-a-2000-hospital-mask-papr-4950905ae2cc
https://www.youtube.com/watch?v=zj_C4GrxfNM&t=102s
https://www.youtube.com/watch?v=xfaswOLIHoQ
DIY PAPR in-depth info
https://www.designnews.com/industry/beyond-n95-hackathon-produces-air-purifying-respirator
https://devpost.com/software/bunnypapr-for-jcrmrg-hackathon
https://bunnyscience.dozuki.com/Guide/Bunny+Science%E2%84%A2+PAPR/4
https://web.archive.org/web/20210202224805/https://bunnypapr.org
https://web.archive.org/web/20210825175428/https://www.viralhelmets.com
https://www.instructables.com/Viral-Helmets-9999-Hospital-Grade-Viral-Protection/
https://www.reddit.com/r/viralHelmets/