Tug... I ordered three hundred kn95s two years ago in Feb from China and gave a whole bunch of them away... not as good as N95, but nearly... and they do help. They are much better than the disposable ones or wearing a bandana... Back at the time, there was a feature showing how the different protections were effective in stopping water droplets... Testing was done with a 'mechanical sneeze dummy' that provided a 'standard sneeze'. They were surprisingly good.

https://nypost.com/article/kn95-vs-n95-masks-exper...

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

-Dik

Water droplets is an obsolete argument, it's long since been proven that the transmission is aeresol. However that's irrelevant.

As engineers we have standards and testing methods to evaluate the performance of materials and products. Can anybody produce any documentation that relates to STANDARDIZED performance characteristics of the KN-95 masks? Especially, anything that predates 2020 or was the KN-95 simply invented to sell to the ignorant?

When taking filter performance, looking at particle size is one dimensional. Saran Wrap and N-95 can both filter particles but one filters particles with much less pressure differential. KN-95 masks bypass around the filter vs N-95. Anybody that wears glasses knows this.

sorry... aeresol... not water droplets. wrong word. The masks work a lot better than nothing and saved lives.

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

-Dik

The definitions are quite different. We are all learning how important definitions are lately.

How can you quantify their effectiveness when you can't quantify their performance?

the main problem with the KN in UK and europe is they are not certified as compliant to anything they are just declared KN standard without any certification.

The actual standard isn't much different to US or EU.

But because they are not certified or tested then they can be made out of recycled toilet roll. It's more a problem of non-existing import checks on the actual certification compliance than the actual KN standard it-self.

A properly compliant KN95 mask will perform much the same as a N95 or FFP2 in Europe.

The KN is not a standard. Nowhere is it documented what is required to achieve the standard, it only parrots the particle size value. You're right that a toilet roll can achieve the same standard of particle size filtration but you can't breath through one.

N-95 respirators utilize electrostatic filtration to achieve high filtration efficiency with back pressures that align with limitations of lung pressure and poor perimeter seals. The N-95 elements are much thicker and more loosely blown than the KN masks.

Regardless of your view of the importance of masking, the disaster is that the engineering community remained silent despite the clear spread of misinformation.

According to this website, there's almost nothing different between N95 and KN95 masks, just the standard by which they comply, but when it comes to the masks themselves, there is almost NO difference whatsoever:

https://smartairfilters.com/en/blog/whats-differen...

Also keep in mind that 3M is one of the largest manufactures of KN95 masks. And please watch the video and look at the chart comparing the various standards used around the world.

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

Who certifies those results. Why is there zero mention of KN-95 before 2020 if the GB2626 standard dates back to at least 2006? Why the sudden blind trust of Chinese suppliers?

3M's authorization to market non-NIOSH respirators was REVOKED well over a year ago:

Quote (3M)

On June 30, 2021, the US Food and Drug Administration (FDA) announced the revocation of the Emergency Use Authorizations (EUAs) for non-NIOSH approved respirators from China and other countries outside the US due to multiple factors including the increase in availability of NIOSH approved respirators. This revocation is effective July 6, 2021, and affects the emergency use authorization of such respirators by healthcare personnel in healthcare settings. Additional information is available on the FDA website at www.FDA.com.

https://www.3m.com/3M/en_US/worker-health-safety-u...

Revocation is hard denial... I wonder why they would use such a term?

Only 7 days from authorized to rejected? Those multiple factors must have been serious.

That's the problem with Chinese certification there isn't any real system there.

So with the way the emergency laws were they could bypass import checks.

EU still required CE certication which can't be done internally in China.

So you do get ffp2 kn masks in Europe but they carry the CE mark.

There seem to be alot of AliExpress products which are USA market which have some nonsense certication on them which is basically a company declared certificate.

I don't have a clue what the USA does for import safety checks.

The stuff that arrives by post has no checks in Europe. The properly imported does.

The kn95 standard itself isn't the issue. Its the lack of import control.

I know you have the UL standard but it's proberly a state function to do the rest of the quality checks. And people would not be happy if it was done federally.

If your face isn't clean shaven then it doesn't matter which one you wear.

Quote (Tug)

Can anybody produce any documentation that relates to STANDARDIZED performance characteristics of the KN-95 masks? Especially, anything that predates 2020 or was the KN-95 simply invented to sell to the ignorant?

It seems that the difference between N95 and KN95 is just the name of the class because one is Chines standard and the other American, in Europe it would have been named FFP2

Quote (MEDS Apotek)

These mouth guards/respirators are available in different protection classes.
In the European standard, these protection classes are called FFP1 filters (lowest level), FFP2 filters (intermediate level) and FFP3 filters (highest level).
During the corona pandemic, the WHO has come out by saying that they recommend FFP2 filters or FFP3 filters as protection for those who work in healthcare, belong to a risk group and for those who feel symptoms.
The FFP2 standard can be compared to KN95 (Chinese protection class) and N95 (American protection class).

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

Quote (Tug)

Why is there zero mention of KN-95 before 2020 if the GB2626 standard dates back to at least 2006? Why the sudden blind trust of Chinese suppliers?

Well it is as Alistair says it is a Chines standard and before 2020 they would have had to rename it either N95 in US or FFP2 in Europe and CE marked it before export.
But when the demand got high and people could buy through internet directly from Chines suppliers the KN95 turned up as an alternative before 2020 you wouldn't have seen it.

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

And how many imports were checked for being sterile?

Probably none.
But as far as I know there hasn't been any known outbakes from packages received either.
A package or product could have been contaminated by anyone that handles it, but the virus could only survive under optimal conditions for a week.
Package sent around the world rarely travels under such conditions.
To hot, to cold, to dry it would have been destroyed.

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

Quote (enginesrus)

And how many imports were checked for being sterile?

None of that grade in Europe. What they were hot on in Europe was contamination with various chemicals from the production process. Which is deemed to be a huge issue with imports from China and also a few other nations USA included. It's one of the big contentions with the trade wars between EU and USA there is all manner of crap which the USA allows for various reasons which is out right banned in the EU and UK. But to ensure its not present would require the complete manufacturing process to change.

We didn't actually use that grade much, there was only a couple of counties had a requirement for that grade hard and some soft. From memory from work, Germany, Austria and Switzerland. The rest of us just had to use surgeon mask style masks.

And there is research being done into the differences between different countries and virus spread depending on which type of masked used. Don't have a clue where it is leading.

There has been absolutely loads of quality data produced by the western healthcare systems which have been exposed to a variety of methods and actions with varying compliance rates.

Its going to take a few years though until the quality studys come out that aren't just for social media clickbait or political soundbites. Quite a lot of the political soundbite stuff the people involved I suspect will be long gone by the time it gets through the system.

I had thought the main difference in efficacy between the two is that N95 use head straps while KN95 uses ear loops. Bushy faces aside and with proper sizing, head straps are better even if the filter material is the same. Is that correct?

Quote (And how many imports were checked for being sterile?)

When I ordered them, I never considered that... funny. I still wear one when I go out and have several dozen left. I'm old and wobbly, overweight and have type2 diabetes... not taking any chances.
For my protection and the protection of others.

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

-Dik

I was going to mention that as well, the head straps verse ear-loops. We have purchased at least four boxes of KN95 masks as well as several boxes of the so-called 'surgical' masks (the blue ones) and they all use the ear loops. BTW, the good news is that they're coming down in price and are easier to find.

Getting back to the means of keeping them in place, I've always suspected that if the ONLY option had been head straps, that a lot less people would have ever worn masks. They can be a real pain, particularly for people with a full head of hair, like a lot of women. Granted, now if you are a man with a beard, perhaps you would be better off using an N95 with head straps, but for virtually everyone else, using a mask with ear loops should work just fine. With that in mind, of all the medical facilities that I've had to visit over the past 10 months or so with my cancer treatment and all, I've hardly ever seen anyone using a mask with head straps. Now most of the medical personnel were wearing the so-called 'surgical' (blue) masks with ear loops. Note that I always wore a KN95 with ear loops and no one ever asked me to swap it for something else or to wear something different the next time I came in.

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

I haven't worn a headband mask the whole time. And only wore the FFP2 masks flying into Germany and Austria, and they were ear loop.

And the ones we get are not sterile, they are though chlorine free and a few other thing's.

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

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

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/PMC80313...

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.

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

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

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)
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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.

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

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

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/artic...

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.

Quote (What about "fit" and "leakage"?)

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

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.

The 3m Technical bulletin stated

Quote (https://multimedia.3m.com/mws/media/1831871O/respi...)

...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.ht...

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.

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/G...

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

https://www.chinesestandard.net/PDF.aspx/GB2626-20...

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.

Not so sure about that Tug, this mimicking thing.

According to the Chines standard GB2626-2006 https://www.chinesestandard.net/PDF.aspx/GB2626-20...

KN stands for

Quote:

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.

Quote:

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

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/respir...

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

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?

It is not the standards that is the problem here, it is the same problem that always occurs when demand is higher than supply, that people and companies starts cutting corners.
And I would say that this will happen not only in China but more or less in all places of manufacturing and in the supply chain regardless of country.
But since China is also know for its replica market of course the concern is much higher when products comes from there and especially when bought by privet persons directly from there and not by medical companies with better resources to validate the products they buy.

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

Quote:

That also raises the question, why are the Chinese using English characters for their own standards? Maybe it's common practice?

English is a world language and Hongkong was "British" as many Asian countries, China sell there products to many none EU and US countries and then it is easier to also have the standards in English.

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

Quote (It is not the standards that is the problem here, it is the same problem that always occurs when demand is higher than supply, that people and companies starts cutting corners.)

and I think part of the problem was that they didn't suggest masks soon enough and the 'authorities' were concerned that they would cause a 'run on' masks, leaving first responders without them.
Tnen it became political.

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

-Dik

In a rational world, it depends on what hazard you're trying to mitigate.

If I want to avoid breathing in harmful particulate, I'll choose an appropriate level of protection, buy something to a standard I understand from somewhere I trust and look for CE or UKCA marking through an accreditation body I recognise.

If I want to minimise my chances of passing Covid onto anybody else, then I'm going to:

a. Go nowhere near the rest of the population if I have any reason to suspect I'm infectious

b. Avoid poorly ventilated public spaces and ventilate the ones I have control over, so that virus concentrations are diluted sufficiently in the far field

c. Stay far enough away from other people (and encourage other people to do the same) to ensure people stay in that diluted far-field.

d. Wear some sort of covering over mouth and nose (and encourage others to do the same) to suppress the plume from coughs, sneezes and sighs of frustration, making the near field/far field boundary more predictable.

e. Trust other people to protect me in the same way, and give those who visibly don't deserve that trust an extremely wide berth.

Within that suite of protections, it doesn't make a right lot of difference whether the face covering is a GSR, something that complies with your favoured EN 149 or NIOSH standard, a Soviet Lepestok mask or a Chinese rip-off of a Gucci bandana.

A.

I agree with Zeusfaber. I took to wearing a P100 respirator, with the exhalation valve covered in a surgical mask. Just as safe for everyone else as surgical masks (better than cloth), both safer and more comfortable for me. Edit: and it has the side benefit that I never have to smell cigarette smoke or other noxious smells when out around people.

Not many know about the R and P series masks. If we truely believe masks work it's truely troublesome we didn't inform those that needed to know that oily environments significantly reduce the effectiveness of the N rated masks. Coincidentally, food prep workers got hit by COVID the hardest and they work on an oily environment. They should have never been allowed to wear N rates masks

Dik's last sentence alludes to that problem.

This looks to be a snipe hunt; it's pretty clear that the CDC is concerned about counterfeit KN95 masks; given that N95 masks are in abundance, why take the risk with masks that might have a 60% probability of being fake?
https://www.newsnationnow.com/health/coronavirus/h...

TTFN (ta ta for now)
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Some time before Covid, my wife and I discovered that N95 masks did a pretty good job of filtering out the obnoxious smell of perfumes worn by people in public venues.

Perhaps I should spray myself with WD-40 and announce that it is MY choice of perfume.



spsalso

N-95 doesn't filter odor. I buy the 3M 6001 series cartridges for my painters. They're N-95 for particles but also filter odors. I also give these cartridges to our crews when it's time to clean out the sewage digesters.

Quote:

I think part of the problem was that they didn't suggest masks soon enough and the 'authorities' were concerned that they would cause a 'run on' masks, leaving first responders without them.

I suspect a large portion of govt simply realized that they had a runaway media faux-fire, knew any action would have little impact, and were afraid of liability bc of it. Personally I'm thankful that we were back in work/school/etc before masks became a popular media discussion point bc it saved a ton of grief and money. I'm also all for PPE and supporting the elderly/unwell, but given the tiny-yet-noticeable numbers of young/healthy folks wearing masks today I feel its time for govt to publicly call-out the paranoia and push those folks toward seeking mental healthcare.

As for mask standards otherwise, the wife and I generally prefer fitted respirators to dust masks and make a habit of reading/following both SDS and 3M/other manufacturer's cartridge recommendations so the details are rather inconsequential.

OSHA does not assign a protection factor unless mask fit test is performed. If you really want masks to be protective the annual fit test is essential.

• https://files.engineering.com/getfile.aspx?folder=e5c55eeb-9c0e-4c85-ab59-e

N95 DOES filter odors, since we noticed the lack of them after donning same.

They do not filter ALL odors, I notice. Again, experimental results.

From this, I reason that they filter some odors, but not all.


spsalso

May reduce the perception and/or penetration of odors, thereby being an effective countermeasure. But N95 masks are not designed to be adsorptive, and the size of typical fragrance molecules argue against a mechanical blocking (i.e. filtering) mechanism of action.

The fluff used to make N95 filters has a large surface area. It is possible that the large surface will attract some odor molecules (surface Adsorption), but the capacity is going to be quite limited.

A real N-95 mask filters by electrostatic charge so there may be more capacity to catch aerosols than we would initially assume. I don't know the answer.

Maybe this perception about things smelling less or odors disappearing when using these masks isn't because of the mask itself but a consequence of it.
Mainly that even though you can breath through it, there is a slight pressure rice on the inside and maybe people unintentionally starts breathing more through there mouth and less through there nose when wearing them, so more of the outgoing air from the mouth goes to the nose meaning less molecules that is detected as smell can get in through the mask from the outside and into the nose.
So less smell.

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

About 20 years ago, I was a hospital IT employee (Florida). Being we all worked in patient care areas, we all had the same safety training as the medical staff. This included PPE rules. (quite a few times, I had to work on equipment in the operating rooms, for instance, where we had to suit up just like the medical staff).

We had a rule that NOBODY was permitted to use an N95 mask unless we were properly fitted for it (the procedure included being put in a hood with some sort of super sweet smelling aerosol added, to confirm that we could not smell it).

When I saw people using N95's, of course this concerned me, as they had a false sense of security.

In terms of permissible exposure limits, an ill firing respirator must be better than no respirator at all. However, it's difficult to determine whether one's exposure is permissible without control of the fit.

With that said, there is no PEL for viruses. Theoretically, infection can start with a single virus exposure.

Quote:

Theoretically, infection can start with a single virus exposure.

Hmmm maybe if you are totally out of a immune system.
Otherwise one single virus would just boost your immune system, put it in the memory bank and wait for the next attack, better prepared.

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

The chances of a virus making it to a cell it can infect are small but once there, in the case of today's most relevant virus, 10^5 copies are produced from the first cell. Individually, I think those copies will have a much higher chance of being infectious because they are released directly in the vicinity of the first infectable cell and similar cells tend to be grouped together. The spread from a single infection may be considerably more than exponential.

I think this possibility is the reason there are no acceptable exposure limits to any pathogenic substances.

For masks that can be true.
But for humans you need to get exposed to get good immunity, and then one single virus ones and a while is the best.

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