Best masks to keep you safest?

The science is irrefutable: the vaccine, masks, social distancing, and ventilation are all essential for curbing the spread and mutation of this damn virus. Unfortunately, lacking any one of those precautions puts a person at risk. This posts focuses on masks because, while something is better than nothing, disposable surgical masks & your average cloth mask just doesn’t cut it against the delta variant. The best choice is a respirator mask: N95, KF94, or KN95. Unsurprisingly, there’s a grey market for respirator masks, which is lousy with no-good counterfeiting scammers. So, how do you find a mask that actually keeps you safe?

My sincerest of condolences to everyone who’s lost a loved one to covid, is struggling with long covid, cannot get vaccinated, and/or is feeling threatened & abandoned by people whose decisions are motivated by politics or conspiracy… And enormous gratitude to healthcare workers, teachers, and all the essential workers who’ve kept us safe & fed, and who’ve single-handedly prevented this country from collapsing.

*None of the links I share on this page benefit me financially or otherwise.

HIGHLIGHTS (scroll down for more detail):

  1. Trusted suppliers of N95, KF94 &/or KN95 masks:
  2. Masks for kids (unfortunately many are sold out):
  3. High-quality reusable/washable fabric masks (scroll down for more detail):
  4. Fixes for disposable surgical masks (demonstration of leakiness below):
  5. Scroll down to the very bottom for tips on safely reusing masks.

<~> <~> MORE DETAIL <~> <~>

  1. The efficacy of masks is sometimes questioned because a covid virus is 0.1 microns, while most masks have openings of 0.3 microns or larger. Wouldn’t a virus just slide through a mask? The answer is NO, and the reasons include:
    • 1–> Viruses never float around on their own— they’re always bonded to something, such as a water droplet or aerosol. Particles generated while talking and breathing are around 1 micron.
    • 2–> Viruses don’t follow a straight-line trajectory. “Brownian motion [is] the name given to a physical phenomenon in which particles smaller than 0.3 microns move in an erratic, zig-zagging kind of motion.”
  2. Details on each type of respirator mask:
    • N95:
      • Particle Filtration Efficiency (PFE) = 95% at 0.3 microns
      • Attaches to the head with: head straps
      • Ideally reserved for healthcare workers, but a good source is
      • Regulating country: USA
    • KN95:
    • KF94:
      • Particle Filtration Efficiency (PFE) = 94% at 0.4 microns
      • Attaches to the head with: ear loops
      • Good source: Any KF94 from BeHealthyUSA
      • Regulating country: South Korea
  3. Aaron Collins, aka Mask Nerd, is a Mechanical Engineer who specializes in aerosols. He’s tested dozens of masks and shared the results with us in an incredible spreadsheet.
  4. The New York Times article about buying masks is behind its paywall (is that ethical?… Here are its takeaways:
    • Say you find a mask on Amazon that gets a thumbs up by someone like Mask Nerd or Wirecutter… well it may still be a counterfeit. The article’s author, Brian X. Chen, learned that Amazon claims to keep an eye out for scams but they’re still out there.
    • What to do? Buy directly from the manufacturer.
      • This nonprofit “buys bulk orders of masks and breaks them up so people can buy smaller batches”:
      • Trustworthy manufacturers include the following, but usually only sell in bulk: (also recommended by Mask Nerd) &
  5. Wirecutter, the New York Time’s review site, has tested many masks and recommended four (but two of them are surgical masks, which are problematic per the next item):
    • *You might consider crosschecking these picks with Mask Nerd’s testing data in #1, above.
  6. What about masks for kids!?!
  7. Are reusable cloth masks over? Not necessarily– these fabric masks have high quality certifications:
  8. Disposable surgical masks, though more comfortable & cheap, are just too loose as demonstrated by this video from Professor of Chemistry Dr. Jose-Luis Jimenez (@jljcolorado) & shared by Epidemiologist Dr. Eric Fiegl-Ding:
  9. The Masks4All Reddit community shares thoughts, tips, and hot sales:
    • The folks in this community are gems… but it can’t hurt to double-check any suggestions to ensure you’re buying from a reputable source. And, you might consider crosschecking any suggestions with Mask Nerd’s testing data in #1, above.
  10. If you’ve already bought a slew of masks and suspect they’re not up to par, toss a cloth mask over top to breathe easier (metaphorically).
  11. How to reuse masks!? I wish this topic were discussed a bit more…
    • Here’s one of the better explanations I’ve seen from
      • Do not reuse disposable surgical masks.
      • “…The CDC says N95 masks can be used for up to five total uses, not to exceed eight hours collectively.”
      • “…After five uses, the integrity of the mask (its fit in particular) has degraded beyond a safe point for use. The same goes for anything above eight hours of total use. To ensure integrity, users should perform a seal check with each reuse.”
      • “If you’re following these procedures, then a rotation policy that allows for at least a week between each mask’s use, while storing them in individual breathable paper bags in the interim, is highly advisable.”
    • If you buy a high quality fabric mask, be sure to read its specific washing instructions. For example, some masks are machine washable, others should not be submerged, some have a filter insert that cannot be washed, and others can be wiped or sprayed with alcohol every night.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: