Stay safer at your dentist's office when you can't wear an N95 over your mouth with this nose-only N95 ReadiMask hack by Lisa Foreman. It is a way to reduce exposure to airborne contaminants during dental and other medical appointments with a genuine NIOSH approved N95 that uses adhesive to stick to your face instead of straps. And it really does work, with some caveats.

The good:
I tried this hack before on YouTube with a quick test and a different model of ReadiMask (a medium, silicone adhesive version). This time I've done multiple tests with the small size, acrylic adhesive version. I even tested with my mouth open to confirm you really can breathe just through your nose even with your mouth open, and get significant protection from this nose-only mask hack. The scores were surprisingly good

My massive list of disclaimers:
Ideally, you should find a great dentist or doctor where there is good ventilation, filtration and the staff and patients are masked up to protect vulnerable people (this is the case at my dentist's office at the moment because of local county regulations). Most people don't have access to that, though, so the nose-only RediMask hack is a mitigation for situations you can't avoid.

This hack is not for everyday use. Your results may be very different than mine. It takes some practice to breathe only through your nose to get the best protection. Not everyone can breathe exclusively through their nose. And not everyone has skin that the ReadiMasks stick well to for a good, reliable seal. So ReadiMasks, and this ReadiMask hack, are not usable for some people. (I'm getting better adhesion with the acrylic adhesive version, the silicone sometimes doesn't stick to me at all.)

This hack is not NIOSH approved, and it likely never will be because NIOSH approval is only for respirators for employees at work, and there isn't any use case I can think of for this for employees at a workplace.

This hack absolutely requires smooth skin to work well. The adhesive mask just floats over facial hair, letting unfiltered air into the mask through the gaps caused by the hair.

References:
I got the ReadiMasks in the video from Alliant Biotech, who are authorized distributors of ReadMask adhesive N95s:

https://alliantbiotech.com/shop/n95-mask

Lisa Foreman's Twitter:

  / findmeabluebird  

---

The fit tests in the video are measured in "Fit Factor", which is the concentration of particles outside the mask divided by the concentration inside the mask. To pass a fit test, a mask needs a fit factor of 100 or higher, which is a seal leak of 1% or less. The 200+ fit factor indicates a seal leak of less than 0.5%.

The test in my previous ReadiMask Nose Hack video used N99 Mode. It tests for total inward leakage, including seal leakage and filter penetration, which can make it hard to tell why a fit factor is low since N99 mode doesn't tell you how the particles got in the mask.

In this video I used the special mode for testing N95 masks. It tests just for negatively charged particles that got into the mask around the seal. This mode assumes the filter media is already vetted by NIOSH or similar organization, so filter penetration isn't measured. In other videos I've gotten lower fit factors for the ReadiMask nose hack using N99 mode, likely because of allowable filter penetration.

An N95 is allowed to have filter penetration up to 5% of the most penetrating particle size at a high airflow. And a seal leakage of up to 1%. A genuine, well fitted N95 mask tested at 100 in N95 mode could theoretically get an N99 fit factor as low as 17 because of allowable filter penetration, which is why N95 mode is used instead, to isolate just the seal leak.

-----
Methodology

Tested using a TSI PortaCount 8020A with an 8095 N95 Companion using TSI sampling tubes and probes. The 8020A was controlled by FitTest Plus on a PC laptop. Daily checks were performed prior to testing. A standard OSHA 29CFR1910.134 8 exercise test including vocalized speech was used for the full OSHA tests.

An 8026 Particle Generator was used to generate NaCl particles, supplemented by combustion particles to reach the levels needed for the N95 Companion to work properly.

-----
Resources

Mask tester and engineer working on fit test solutions:

   / @coll0412   /
MaskNerd on Twitter

Mask fit testers on Twitter:

@FitTestMyPlanet
@CriticalAerosol

Home fit testing kit maker on Twitter:

@__philipn__