KN-95 vs N-95 4

[TugboatEng]

Now that the winds are starting to calm down, maybe it's time that review the engineering information. It's odd that our USA CDC NEVER recommended the use of KN-95 masks. They never existed before 2020 and why would a Chinese standard use USA characters? The CDC edicts always stated N-95 and it was only our media that tacked on the N-95 "OR" KN-95 terminology. Talk about spreading misinformation. If N-95 is truely effective, how much blood is on the hands of our media for pushing the fake KN-95 standard? Also, the waste and pollution...

I'm really surprised that no engineers that understand anything about filtration came forward on this? A piece of Saran Wrap filters better than a N-95. How is the KN-95 standard relevant?

 

[EdStainless]

I never expected any mask to offer me much protection.
I haven't been professionally fitted and I don't have the usage discipline.
But they do help minimize me giving things to others.
On the other hand my daughter works as a PT in an in-patient rehab hospital.
She has kept wearing masks (correct size N95) the whole time.
And now that it is flu season, she has gone back to wearing a face shield also.
Is Europe having outbreaks of other virus as well (RSV)?
Not to mention the other corona viruses, the common cold.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[spsalso]

When it hit the fan, I already had a supply of (work related) N95's, and so wore them. I have tried the ear loop ones, and find my ears don't like it. Why means I don't like it. So I have stayed with N95's.

I find them easy to fit: just bend the wire thingy until it matches my nose, and I'm done.

They occupy space on my face where my glasses would like to be, so I rarely wear both.


spsalso

 

[TugboatEng]

Something to consider, the filtration method for ultra fine particles in N-95 masks is by "electret". The masks do have a shelf life as they lose their electrostatic charge over time.

From an engineering standpoint, this is an important consideration if we are looking to stockpile. Perhaps an idled production facility would be a more economic approach.

Not that we are using gamma irradiation to sterilize our masks but this study by Sandia NL correlated a loss of charge with a 40-50% reduction in filtration efficiency in the 200nm particle size range.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8031388/

 

[Sym P. le]

So lets simplify this discussion. N95 is a medical standard with legal ramifications whereas KN95 is a marketing gimmick passed off as an economical improvement of the former. In short, a lie. Any attempt to equivocate the two needs to be called out immediately.

 

[JohnRBaker]

Is this what you mean by an "attempt to equivocate the two"...

...and if so, how would you suggest that we go about "calling it out immediately"?

John R. Baker, P.E. (ret)
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[dik]

Whereas KN95 is a different, but recognised standard...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[IRstuff]

I think the issue has more to do with the proliferation of counterfeit masks, and revoking the EUA eliminates them as a significant factor in the US market.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[Sym P. le]

GB2626-2006 is apparently a Chinese standard. The CDC is pushing back against any references by manufacturers or distributors of KN95 masks to CDC/NIOSH standards or assesments here and here and here (pdf download).

Fair game to market a mask but not to glam on to a regulated standard.

I chose to wear a KN95 instead of the blue surgical masks as I felt they offered a more secure fit. I do feel duped into believing they were somehow at a similar standard to the N95. That is clearly not true, in fact, a lie.

 

[dik]

To protect markets? Looking at the table above, there does not seem to be much difference...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[spsalso]

I do wonder how the surgical mask standards fit in with this mask discussion. Are there any? What about "fit" and "leakage"?

I get the impression that pasting "surgical" before the word "mask" is supposed to impart the complete endorsement in every possible way of the medical and scientific establishment.

Or not.

"surgical mask"
"surgical strike"

Who could argue with either?

Maybe I should file a "surgical tax return".



spsalso

 

[TugboatEng]

The surgical mask appears to be one of those assumptions that seems logical but doesn't necessarily have any evidence to back the conclusion as of 1997.

https://pubmed.ncbi.nlm.nih.gov/9013247/

I wish I could access this article from 1960:

https://jamanetwork.com/journals/jamasurgery/article-abstract/558661

But, these questions are outside of our expertise as engineers. I am happy to see some engineers finally speaking up about fake standards. That was my intention by starting this topic.

 

[dik]

I've used tanks in chlorine rich environments and facial hair and fit are extremely important...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[Alistair_Heaton]

I think the use of "surgical" mask is purely descriptive method of describing them and not an actual standard.

I am told by those that use them while cutting that they are only worn to stop splashes going into their mouths, and fluids coming out of theirs dropping into the open surgical area. In the UK at least the gas pusher wouldn't be wearing one normally, they would be behind a cloth shield at the neck.

They apparently do have a quantifiable effect on post-surgical infection rates. To add they are the first stage of a tree of prevention methods. And they are dual purpose protecting the user, they all wear safety glasses these days as well. Only some procedures require them in the protocol but it's pretty standard for everything.

And they need to be able to smell while working in most cases.

I wouldn't say the kn95 is a fake standard, it's more a fake claim that the product complies with it. Which in some cultures is normal and no repercussions will result from doing it. We have the same issues in europe with certain standards, the fire resistance of products is a big topic at the moment especially with building cladding.

 

[FacEngrPE]

The 3m Technical bulletin stated

https://multimedia.3m.com/mws/media/1831871O/respirators-from-asia-imported-and-distributed-by-fema-technical-bulletin.pdf[/URL]]...it is reasonable to consider China KN95, AS/NZ P2, Korea 1st Class, and Japan DS2 FFRs as “similar” to US NIOSH N95 and European FFP2 respirators, for filtering non-oil-based particles such as those resulting from wildfires, PM 2.5 air pollution, volcanic eruptions, or bioaerosols (e.g. viruses).

3M did not claim the KN95 was NIOSH compliant.

A note on the science. early in the pandemic, the medical community was holding on to bad science
The 60-Year-Old Scientific Screwup That Helped Covid Kill All pandemic long, scientists brawled over how the virus spreads. Droplets! No, aerosols!
Once the medical community started to listen to environmental scientists about how particles of various sizes move in the air, the game changed dramatically.

Do I think the masks work? With the importance of mask fit, and the uncontrolled manner in which many users applied them are considered, the capabilities of the mask filtering material are less important. For many users the "Bypass Ratio" significantly reduced any masks effectiveness, this is why we do mask fit tests in industry. New NIOSH Study Supports the OSHA Annual Fit Testing Requirements for Filtering Facepiece Respirators, Posted on January 5, 2016

Early on there was a line of thought that we would all eventually get covid, and that the purpose of masking was to reduce the rate of transmission so that the medical community has time to figure out treatments. By now - symptoms or no symptoms, most have been exposed.

https://www.cdc.gov/mmwr/volumes/71/wr/mm7117e3.htm

 

[TugboatEng]

The reason I use the word fake is that using the time window search function in Google "before:2020 KN-95" yields no results. The KN-95 term was coined in 2020 to mimic the US sounding standard to sell masks.

Note that Google has adjusted their algorithm a bit since I discovered this. You will get search results with spurious dates but if you follow the links they all make references to post 2020 references.

 

[Alistair_Heaton]

well, a google search from outside the USA shows it was brought out in 2019 and replaced the GB 2626-2006 standard.

https://www.chinesestandard.net/PDF/English.aspx/GB2626-2019

And looking at the 2006 standard it also referenced KN and KP product standard classes.

https://www.chinesestandard.net/PDF.aspx/GB2626-2006

It has the previous standards listed so you can trace back the usage, I seem to remember back in the Uk in the 90's we called them N95 masks as well and it was 2005 ish they started calling them FFP, presumably that means something in French.

I don't think the N means American I think N95 is something to do with the particle size it stops.

 

[RedSnake]

Not so sure about that Tug, this mimicking thing.

According to the Chines standard GB2626-2006

https://www.chinesestandard.net/PDF.aspx/GB2626-2006

KN stands for

4.2 Classification of filter element
Filter elements, according to the filtration performance, are divided into two
categories: KN and KP. Category KN is only suitable for filtering non-oily
particles. Category KP is suitable for filtering oily and non-oily particles.

And 95 is the grade of filtering capacity in % during the circumstances required.

c) Number of this Standard and year number. The filter element shall be
marked with the filter material’s grade, which is marked with the
combination of this Standard number and the grade of the filter element,
such as GB 2626-2006 KN90, or GB 2626-2006 KP100.

I wouldn't be surprised if the same Chines manufacturer where manufacturing mask for both China, EU and US just labeling them differently KN95, PFF2 or N95 depending which market they are delivered to.
For EU there is no need for a third party validation it is enough that the company say they are upholding the EU standard.
Of course there can be test made if there is complaints or if a company wants to be sure, or by some medical board doing sample tests just to be sure the quality is what it says it is.


“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[TugboatEng]

Ok, I concede that KN-95 was a pre-existing standard. Here is a document from 3M listing their masks that meet KN-95. Interesting to note, the flat fold masks that became dominant were always KN-90, none were 95. 3M does have a flat fold mask that is N-95.

https://multimedia.3m.com/mws/media/929854O/respiratory-protection-for-airborne-exposures.pdf

 

[Alistair_Heaton]

But Tug your concerns about if the actual products labelled as such were capable of that standard are more than valid and I agree with your concerns. 3m I think you would be safe enough trusting, most of the other suppliers not so much

 

[TugboatEng]

I will also note that I am using English characters to search for Chinese references which may limit my returns. That also raises the question, why are the Chinese using English characters for their own standards? Maybe it's common practice?