I've alluded to the fact that I spent many years working on a nation-wide(US) water testing project once and that I don't own the results, they were never published, and I can't specifically give away those results that I don't own. All of this recent talk about PFAs in water is absolutely killing me. This new water testing is going to take place over the next three years, and it's important to note that it's *only* talking about a handful of chemicals.

I've found that particularly US-based people really think their water is great and vastly overestimate how great it is. It comes out of the tap, you drink it and you don't die of waterborne illnesses. Woohoo. Really, it's an accomplishment.

But until you spend time in a water testing lab you don't really begin to realize how much isn't tested for in that water you drink and bathe in. It's just not possible.

People would ask me all the time "How do I get my water tested for everything?" You can't. Think of the story recently about how many chemicals are in plastics, for instance. 16,000-ish and over 4,000 that are potentially hazardous. Basically zero of those are tested for in any way whatsoever. To get something tested, someone has to care enough that it's there in the first place. Then someone has to create testing procedures and standards. Then there has to be a market for that test.

Let's JUST talk about PFAs. You know how many there are? Ballpark is ~15,000 different PFAs. You know how many are tested in this new EPA program? 25.

Now that we've established that, just how likely is it that testing will find PFAs in YOUR water in the US?

https://www.ewg.org/interactive-maps/pfas_contamination/

Pretty likely.

While I can't really talk about what states are likely to find if they honestly look, what I do talk about, and have for probably 20 years now, is what I did when I realized what's really in your water. I put in a whole home filter outside of our home to filter out a lot of stuff for showering and hand washing. No one so much as cleans vegetables here unless the water comes from the reverse osmosis system in our kitchen. Drinking water, ice, pasta water, fruit and veggie washing water, etc all comes from that.

I'm very sensitive to the fact that not everyone can do all of that. It's a step in the right direction that the EPA is beginning to do something about this, but it's far later than it should be and doesn't go nearly far enough. All I can say is that you should demand better, and not just about PFAs, but all contaminants in your water supply.

And before anyone asks, yes, the spring water on the homestead is about as clean as you can find anymore. Under 10 TDS and no contaminants that I've found to date. Again, can't test for everything even if you wanted to and had a million dollars to throw at it. It was a major selling point on the property for us.

I've got a few DMs overnight asking about PFAs in masks, and so rather than discuss it all in private, here's my thoughts.

In short:

Yes. Some masks will test positive for PFAs.

No. I don't think it's a big concern.

Here's why. The spreadsheet going around about 3M products, at least the version I've seen, absolutely does list the Aura and some of their filters for some of their reusable masks like the 6503, which I own and use, but in extremely tiny amounts. A cup of water from your sink, unfiltered, probably has more than your mask.

You're, probably, talking tiny amounts that are due to manufacturing. Do I trust 3M about that? No. From professional and personal experience I wouldn't trust 3M if they told me the sky was blue. Don't trust them about anything. Would it surprise me if I later found out that they soaked the Aura in PFAs for a week to make sure it didn't get wet? No. There are some true believers in PFAs in that company who think they're the greatest thing and should be on everything. Do I think that's what's going on? No.

If I found out that they did, in fact, soak them, would I avoid them? Of course. But that doesn't mean you stop masking. Even if EVERY mask in the world tested positive for PFAs, I'd pick my poison and mask up when I needed to.

But, really, manufacturing is a real problem for trace amounts of PFAs. They're everywhere. I once knew a guy who fixed manufacturing machines. He worked for a big company and had a multi-state region where he just travelled around and fixed machines on manufacturing lines when they went down. Back before people worried about PFAs much, he had an SOP he followed, and the last step on most things was to spray the parts he replaced down with a PFA spray. Why? Because it kept grease out of the product on the line. Everything coming off of those manufacturing lines would have some trace of PFAs on them, even though the company who was responsible for the products had no idea.

This hasn't really gotten any better since. Supply chains are absolutely riddled with PFAs. Even companies trying their absolute best have very little control over it in the end.

The paper that's often cited about masks and PFAs is the following, and I believe it's really the only one.

https://pubs.acs.org/doi/10.1021/acs.estlett.2c00019

What you have to realize about this is that if you dig into the supplementary info, there was *some* PFA contamination on the N95 they tested. But the vast majority of it was on "RC-1" through "RC-6", and "FF". RC here stands for reusable cloth, and the FF is a mask designed for, and marketed to, firefighters.

Let's deal with the firefighter's one first. Firefighters are, unfortunately, laden with PFAs. Firefighting foams for Class B fires are basically PFA foams. While they're being phased out, they still exist. Firefighting equipment then is often soaked in PFAs. I assume the mask in the study for firefighters is soaked in PFAs for some fire resistance.

Now, the reusable cloth masks. I hope no one's using those today. But, let's stop and think this through for a moment. If cloth masks have PFAs, what does that say about my clothes? I hate to tell you, but, a lot of clothes have PFAs.

Yes, so does bedding. Carpets. Paints. The seats in your car.

I've had a series of revelations in my life through my research. In the 90's and the following decades I removed everything that I could that off gassed VOCs. Then I removed plastics. Then I got rid of everything that I could find that had PFAs.

Proportionally, the first two weren't that hard. PFAs are damn near impossible.

So what do you really need to focus on? *Not ingesting them*. I think that's intuitively clear. Sure, you don't want to touch poison, but you REALLY don't want to pour a glass of it and drink it, right?

In order of most important:

Clean your water. I think I've discussed this ad nauseam and everyone's probably tired of it.

Remove it from your food sources. Yes, the FDA banned it from food packaging in February, but that doesn't take effect until around 2026. When I worked in the national lab system you know what we called that? Not today's problem. Because anything that was funded or unfunded during the next presidential administration was just as likely to happen as not happen in the end.

Look out for cosmetics. If not ingesting it is the main goal, not rubbing it on yourself everyday is the next goal.

Math time!

The paper cited above about PFAs in masks was designed to study their accumulation in dumps. I don't want to gloss over that, but, I'm going to anyway.

On an individual mask basis, you have to do some math to figure out how much PFA contamination you're talking about, because they were looking at it per square meter of mask materials.

The N95 in the study tested out at 15.2 micrograms per square meter. Your mask is obviously not a square meter.

I'm going to make an assumption and do some rounding here, just to get a ballpark number.

I pulled a 3M Aura off of a hook by our door(my wife wears one to get the mail, or slap on if the FedEx guy keeps knocking and won't go away) and a quick measurement tells me it's around ~6" x 8" or about 300 square centimeters. There's 10,000 square centimeters in a square meter, so, one Aura mask is roughly 3% of a square meter.

15 * 0.03 = 0.45 micrograms of 3 PFAs combined on a single mask. Most limits for PFAs are listed in ppt(ng/L) or ng/kg body weight. So, 0.45 micrograms is 450 nanograms.

So, in that same ballpark, what does it mean?

*I am not saying that there is a "healthy" PFA dose. Your body struggles to get rid of it and it doesn't ever break down.*

The European Food Safety Authority says that the tolerable weekly intake of PFAs is 4.4ng/kg of body mass. That would mean ~220 pound person could eat their N95 every week and stay within the limits(please don't).

The state of Virginia says that your water can legally contain 150,000 ng/L. In Virginia you could drink 333 N95's worth of PFAs continually(please don't).

Under the new EPA guidelines that will go into effect, maybe, years from now water must be under 4ppt. So, one N95 might contain the amount of PFAs in a month's worth of your drinking water if you drank 3L a day, and if that goes into effect and is enforced.

What does it mean for what you're actually exposed to already?

In a study some paints had upwards of 700 ppm total Fluorine. If, as expected, the PFA in the paint formulation was 6:2 FTOH, that would be around 50 ppm of that PFA, or 50,000,000 ppt. Thank goodness we don't ingest paint, but, I'm willing to bet we're all surrounded by it. How well encapsulated is it?

https://habitablefuture.org/wp-content/uploads/2024/03/97-pfas-in-paints.pdf

In a bad scenario, my friend who is now facing kidney failure has been drinking neighborhood water that was tested at ~59,000 ppt in 2016 for a couple of decades, or so. He may have been drinking upwards of 180,000 nanograms a day. That's the same as ingesting 400 masks worth A DAY. I do not recommend this.

https://www.ewg.org/interactive-maps/pfas_contamination/#about

Even in rain water, tested amounts of PFAs were between 1 and 40 nanograms per liter in urban environments, or, often upwards of an N95 masks worth of PFA for every 10L of rain water.

https://pubs.acs.org/doi/10.1021/acs.est.2c02765

Yes, there's studies that absorbing PFAs through the skin is similar to ingesting them.

https://www.sciencedirect.com/science/article/abs/pii/S0278691520300016

If the data we have on N95's is in the right ballpark, it's just not high on the spectrum of PFA concerns in my opinion.