💥 Fit-Test Fun: 3M Aura Smash-Up 💥
Inspired by the question below, I recently decided to test a worn-out Aura to see if it was still protecting me. The results were surprising! See alt text for disclaimers.
⬇️
Inspired by the question below, I recently decided to test a worn-out Aura to see if it was still protecting me. The results were surprising! See alt text for disclaimers.
⬇️
https://x.com/tincanfire/status/1785759466568212654?s=46
There was just one problem: I didn’t have a totally worn-out Aura. Luckily, after searching the car I found a questionably past-its-prime 3M 9210+ Aura used for recent eclipse travel. ⬇️
I then used the following improvised and totally unvalidated protocol: ⬇️
1- Squished entire mask, including nosewire, into little ball in hand x 20. ⬇️
2- Used both straps to slingshot mask across the room x 20 (cat did not appreciate this part). ⬇️
3- Wiped down kitchen counters and dining room table with outside of mask. ⬇️
Using this badly mistreated but well-seasoned mask, I ran a full set of 12 exercises with a Portacount in N99 mode, using an adversarial @FitTestMyPlanet protocol using a jaw spacer to simulate facial movement. ⬇️
Results: HMFF or harmonic mean fit factor (conservative average score) of 2650, which means the air inside the mask is 2650x cleaner than the air outside it. ⬇️
This is equivalent to a 3.4 log reduction in the number of particles, and filtration efficiency of 99.93%. For reference, a fit factor of 100 is equivalent to N95-level protection for this type of testing. ⬇️
How does this compare to my usual results with this mask and this type of testing? I usually get a HMFF of around 1500, which is a 3.2 log reduction and 99.90% filtration efficiency. In terms of actual protection, the worn-out Aura performed as well as a fresh one. ⬇️
From now on, I’ll be more confident reusing Auras until the straps loosen or until they get dirty or smell off (except in high-risk situations which deserve a fresh mask). ⬇️
NB: Level of protection will vary for everyone and for each type and brand of mask, so it's always a good idea to do a home or professional fit test. If you often reuse masks, consider fit-testing them again after a reasonable period of use to see if they still pass.⬇️
Oh-- @3M, please make a black Aura and different mask sizes for different faces. Thanks!
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