I posted recently about how ReadiMasks have not been NIOSH approved for over a year, a change that ReadiMask did not share with the public. ReadiMask have finally published a public statement: "ReadiMask is open. We plan to restore our NIOSH certification with our next production run..."

AirGradient is releasing a new portable open source air quality monitor in June. CO2, Particulates and TVOC. And built in GPS to track *where* pollution is bad. 199.00 pre-order price - not including shipping and customs which are calculated at checkout. www.airgradient.com/portable/

$5 air quality monitors from Ikea? Should you get one? My local Ikea is selling off discontinued VINDRIKTNING particulate air quality monitors super cheap. I figured I could get one for every room, which could be fun. youtube.com/shorts/6owRP...

Even after 41 programed don and doff cycles over 41 hours I still couldn't get the wrinkled crepe paper look that 3M Aura straps get when they are worn out and likely to break.

Testing 3M Aura strap creep the low(er) tech way, with a mannequin head and a stretching board with a force sensor. This is to compare if the static stretching board results match the mannequin head results. And to compare how these static results compare to a don and doff cycles every two hours.

ReadiMasks are no longer NIOSH approved. And haven't been for over a year. Voluntary Rescission of ReadiMask's NIOSH approval was granted March 25, 2025 at the request of Global Safety First, LLC.

Stress testing 3M Aura 9205+ N95s. Over 60 cycles to 3x stretch. No failure. In this test the machine stretched the top headstrap of the aura. To simulating donning, the strap is repeatedly stretched to 3x the relaxed distance. The video is 30x. Cross head speed was 1000mm per minute.

Why you can't trust Amazon reviews of test instruments, part 1000. This pinless wood moisture meter has a 4.6 rating by people who have no idea the product isn't giving them wood moisture readings at all.

Doh! The adventure is over for tonight. Need to debug my programing. I crashed the clamps together during my doff step. I did have a 2 lb pinch force limit set so no harm done. But I will need to start over later this week to figure out what caused the issue with my doff cycle going down past zero.

Sending a 3M Aura on a 40 hour strap stretching adventure. I programed the testing machine to cycle the Aura to 2.5x stretch for 2 hours, then down to 1x stretch and immediately back up to 2.5x. Repeat 20 times. Yay automation!

Who doesn't want to test N95 straps with a 225 pound programmable force tester!? Is it just me? Sigh. I got this Bad Boy used off of Facebook Marketplace. It can do cyclical and break testing with 1000 Hz sampling. First up, 3M Aura straps.

Dried out nose and lungs from dry cabin air when flying? Would a "humidifier" mask help? Or are they a scam? I got a Facebook ad for the $90 Kuvola mask to trap humidified air to help you breathe better. N95s already do this and they filter air at the same time. reddit.com/r/Masks4All/...

Some "dust masks" are real particulate respirators, and some are comfort masks for nuisance levels of non-hazardous dust. Using the same terms for both is confusing so I call N95s respirators and try to always remember to include "nuisance" when discussing "nuisance dust masks."

Respirator manufacturer VitaCore is making sophisticated custom masks from 3D face scans - for CPAP. The technology could also apply to custom respirator masks, and is way more sophisticated than you might expect. vitacore.com/formfit 🧵

N95s can lose dimensional stability over time, potentially allowing seal leakage of unfiltered air into the mask. A 2024 study found that 38.7% of N95s tested failed a fit test after a single full work shift.

Some 3M respirator filters are way easier to breathe through than others. 3M won't tell you which ones, so I tested them to find out. Based on the breathability results, I'm going to go with the 2291 Advanced P100s or the 2071 P95s when I need particulate filtration for a 3M bayonet filter mask.

BreatheX is telling welders to ditch their respirators and wear non-certified BreatheX nostril filters instead. Should they? Nope, nope and nope. 🧵

I've just added an hours meter to the @nukit.bsky.social Lantern I was sent. Now I can test the lamp life in a more robust manner.

Love 'em or hate 'em, there is a great new write up on the hows and whys of bi-fold respirators, the shape most people associate with KN95s by Vasilisnp2. reddit.com/r/Masks4All/...

So...this showed up on my doorstep... ...an @nukit.bsky.social Lantern Far UV-C lamp, which can safely sanitize air of germs at UV energy levels that are skin and eye safe for people.

Harvard doctor Paul Sax MD wrote an OpEd in the New England Journal of Medicine to get rid of annual mask fit testing without knowing how mask fit testing works. voices.nejm.org/doi/full/10.... The NEJM needs to vet its OpEds better. And Paul Sax MD needs to learn how mask fit testing works.

Duckbill N95s are super breathable masks that are very protective, but which one is the most breathable? The most breathable one I tested is the 3M VFlex 1804 Surgical Duckbill N95, testing at a very low 57.8 Pascals. Surprisingly, it is thicker than others but still more breathable.

@adamwong.bsky.social released AirFanta's wearable air purifier to market. It's meant to be used close to your nose and mouth to minimize how much unfiltered air gets entrained with the filtered output. But it is not meant as a 1:1 respirator replacement.

Very cool design features in the updated Torch 2 Far UV light that can safely sanitize ambient air while being safe for people. I like the removable battery and replaceable lamp, meaning that the lifespan of the Torch 2 is not limited to the life span of the lamp or the rechargeable batteries.

Google AI lied to my face about respirator filters. You can't trust AI to give accurate information on respiratory protection I searched for info on the Peke Safety Powercap's filters by product code to find their rating. The confidently wrong Google AI result I didn't ask for told me they are FFP2

This popular fan powered respirator isn't as protective as people think. Its European TH1 certification allows up to 10% inward leakage. The Powercap is a legitimate PAPR but not nearly as good as NIOSH PAPRs, or the other two EU PAPR classes: TH2 - 2 % leakage allowed TH3 - 0.2% leakage allowed

Be cautious in reposting the "time to infectious dose" 2-way masking graphic. It is still true that everyone masking is quadratically more effective than 1 person masking at infection control from airborne disease. But the initial starting point is purely hypothetical for illustration purposes.

Huge 75% off discount on NIOSH-approved strapless ReadiMask N95s. 50 for $18.55 Discount code "NonSmokingZone" Non-affiliate link: alliantbiotech.com/product/read... H/t to u/doililah for the code.

For many, pseudoscience is comfort. Pseudoscience is easy to do and understand. Science is hard and can give us answers we don't want to hear.

No. The answer is no. You can't trust UV sanitizers from Amazon. Amazon gave me this one to review. It's supposed to output sanitizing UV-C light, but only gives off UV-A. Which may be a good thing. The FDA warned that UV wands with un-guarded UV-C sources can expose you to unsafe levels of UV-C.

Breathing clean air is as important to your health as drinking clean water. N95s are personal air filters, and they can help protect you from particulate air pollution from wood smoke, and much more. @capublichealth.bsky.social is doing a great job with their public health messaging.

Yeah, that feeling when someone right next to you starts wet coughing over and over, and you wish you were wearing a mask? You wouldn't have that feeling if you had already put on a mask before going indoors around other people during an uptick in infection. Well-fitted N95s etc. work.

Congratulations to OpenAeros on the release of this evolutionary open source instrument. Lab-grade results with open source flexibility and accountability, all at a lower cost that current CPCs in its class. Someday I hope to get my hands on one :-)

Aaron Collins & the team at OpenAeros have announced the OpenCPC, a continuous duty sub-micron particle counter that is open source. At $5,000 it is much cheaper than closed source models. youtu.be/2OGohkAd2Cg Open source instrumentation fundamental to making science more accesable.

Should you trust N95s to fit well past their expiration date? Depends on the specific model and storage conditions, including how they were stored before you got them and have no way of knowing. This study fit tested stockpiled masks that were from 9 to 13 years old. www.cdc.gov/niosh/media/...

Amazon has been selling giant boxes of 440 3M Auras as low $27. That's 440 masks for super cheap. But can they really be any good? I bought a case & measured the properties & performance compared to Auras from other sources as part of my Kanro grant for testing respiratory protection Video link ⬇️

You know how styrofoam peanuts cling to a statically charged balloon? You can make a solid puck of plastic that does the same thing, but stays permanently charged - it's an "electret," the static charge equivalent of a permanent magnet.

Notoriously thin-skinned pro-Covid doctor Vinay Prasad has gotten YouTube to terminate a critic's entire YouTube Channel by using multiple copyright strikes as a tool of censorship. @mmasnick.bsky.social has been warning us about this type of abuse of copyright for years.

Can you tell scam respirator ads on Facebook from legit ones? I checked out if the fan powered respirator in this ad by PekeSafety is a total scam, an awesome deal, or somewhere in between. Video link in next comment.

This is getting out of hand.

Don't get fooled! If you search for "3M Full Face Respirator" on Home Depot's website you'll get fakes and non-NIOSH masks. Weirdly, Home Depot doesn't sell full face 3M respirators, but instead of just saying so you get 1,414 results. The 1st is a fake 3M mask - a generic knock off of a 3M 6800.

Remember back when a bunch of people got discounted new CleanSpace2 PAPRs from Fisher Scientific, but they were all DOA because the non-replaceable batteries self-discharged in storage and permanently died? www.reddit.com/r/Masks4All/... Well, CleanSpace now has a fix for that: It's your problem.

Does a beard really reduce respirator fit? Yes. Check out this video by Pro Safety and Training in Australia. They fit tested a bearded employee, Dan, before and after shaving. The difference in mask seal is massive. youtube.com/watch?v=dCWo...

**Can you** wear a respirator over a beard? Yes. **Should you**? No. You can get some protection from a respirator over a beard, but you won't get the full protection the respirator is capable of, the protection you bought it for to protect your health. youtube.com/shorts/EA-ZK...

Don't use this CPAP muffler. It sheds aluminum shards. (Video link in the next comment.) CPAP mufflers like this one are supposed to quiet the output of noisy travel CPAPs Amazon sent me this one to review. There are two issues to be aware of - metal fragments, and pressure drop.

Good quality nose wires are the "secret" to tri-fold masks that fit me. The same exact mask can fit great or leak terribly depending on how good the nose wire is. I tested nose wires from 4 masks to see how well they work. Video link in the next comment.

How strong is the nose wire in a 3M Aura? That's a 248g of weight hanging off of a 3M 9205+ Aura nose wire placed across 65 mm span — over a half pound of weight with barely any noticeable deflection. The conformable but strong 3M nose wires are one of the reasons many 3M N95s fit me well.

All N95s can and do filter viruses, whether or not they say so on the box. N95s are particulate filters. Airborne viruses and respiratory droplets are particulates. The manual for 3M Aura N95s specifically mentions that they can filter viruses, aka "help reduce inhalation exposures".

Testing the Forged Air Respirator - the good and the bad of outside of the box design and engineering. Its big, flat filter is like a Flo Mask on steroids. The large surface area filter gets you good breathability and speech intelligibility.

Why do N95s work? Cooper the cat shows us how. Electrostatic attraction. It works really well at attracting and capturing particles. N95 filter media is electrostatically charged, making it very efficient at grabbing even ultra-fine particles out of the air.