Why your KN95 fails a fit test

Your Chinese made KN95 has two problems and surprisingly, it’s not the filtration. It’s the seal. In order to effectively filter the air you breathe, the air has to pass through the mask and not around it, which is the path of least resistance. There are various grades of KN95s but most of what we are seeing imported into the U.S are the cheap consumer grades. The various grades are:

GB 19083-2010 are for ICU/ high risk area. This is ideal for healthcare setting
YY 0469-2011 are for less high risk medical floor and surgical use
YY/T 0969-2013 are for general medical use in normal medical environment.
The following are non medical:
GB/T 32610-2016 consumer grade, for pollution
GB 2626-2006 industrial use, for dust. This is mostly what I am seeing in the U.S.

You can view these designations here:
http://www.cem.org.cn/default/content/index/id/12357
Open this in Chrome, wait for it to load, then hit translate.

A lot of people have ordered these and to no ones surprise, they are failing fit tests.

So the first flaw is the metal wire across the nose. It is thinner than a NIOSH N95 and doesn’t retain it memory very well. Therefore, it pulls away from the sides of the nose and allows air in. The easiest way to fix this is just a piece of tape across the nose parallel to the top of the mask.

This is annoying, because it doesn’t allow you to take the mask on and off easily, but it is easy to fix.

The second problem is obviously the ear loops. If you have worn an N95, you know that it should be uncomfortable and it should be snug on the face. Ear loops are not that snug. There are several work arounds that I will show here.

Possibly the easiest, is just a paper clip.

Another option is rubber bands. Fix the Mask shows you how to use 3 rubber bands to get a tighter seal around the mask.

You can also use them to tighten the ear loops. Loop two rubber bands together.

Loop one side through one ear loop.

Then loop the other rubber band through the other ear loop and back through itself.

You can now adjust the tightness by pulling on the blue loop.

Other options include 3D printed holsters, like this awesome Boy Scout made.

or homemade ribbon and buttons.

If your filtering capabilities of you KN95 are sufficient, you can improve the efficacy of your mask with these work arounds.

For the record, $7 for a poorly fitting KN95 that doesn’t have a good seal is absurd.

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