On PFAS/PFOS

On The Right Filters Reading On PFAS/PFOS 5 minutes

(This article is also available as a podcast at https://therightfilter.substack.com/)

When we talk about PFAS/OS, what are we actually talking about? Let’s start with Wikipedia.

“[P]er- and polyfluoroalkyl substances (PFAS or PFASs) are a group of synthetic organofluorine chemical compounds that have multiple fluorine atoms attached to an alkyl chain”. PFOS are a type of PFAS which “is a chemical compound having an eight-carbon fluorocarbon chain and a sulfonic acid functional group, and thus it is a perfluorosulfonic acid and a perfluoroalkyl substance (PFAS)”

Okay that didn’t make anything clearer. Let’s try this.

PFAS is what you find in Teflon. PFOS is what you find in Scotchguard. And PFOS is a type of PFAS.

From firefighting foams to fabric protectors, to anti-reflective coatings to makeup to non-stick frying pans, PFASs are used when you want something to not get wet. And to make sure the thing stays not wet, PFASs have to be pretty strong. Otherwise, water could dissolve it right off.

And there’s the problem.

See, PFASs have an extremely strong chemical bond to hold it together. It’s so strong that even after 8 years, more than half of it would not fall apart.

But, to put that in context, it would take somewhere between 58 and 1200 years for a plastic gallon jug to decay halfway. PFASs are tough, but not as tough as plastic. So if we can find plastic at the bottom of the ocean and floating in the clouds, it shouldn’t be surprising that we can find PFASs all over the place.

Still, the scale of it is alarming. In 2024, 71 to 95 million people in the US “rely on groundwater with detectable concentrations of PFAS for their drinking-water supplies prior to any treatment.” Recent studies have suggested that it would take 40 years to flush out the contaminated groundwater in parts of North Carolina.

And in Europe, the byproduct of PFASs breaking down, called TFA (trifluoroacetic acid) was found in “in 34 of 36 tap water samples and in 12 of the 19 bottled mineral and spring waters.”

In Denmark, they found that TFA levels since 1960 have been going up 400% every 20 years. Before 1960, there were no measurable levels. Between 1960 to 1980 it was 0.06 ppb on average. Between 1980 to 2000 it jumped to 0.24 ppb. And between 2000 and 2020s, it contained 0.6 ppb on average. And it doesn’t look like it’s decreasing.

The worst part is we are still learning about how, exactly, PFASs affect something as big and complex as human beings. We know it can disrupt our microbiomes, but only recently found out that that disruption can affect our kidneys. We know that pregnant women, in general, are more sensitive to PFASs but only recently did we find out that “women with higher levels of PFAS …weighed more and had more body fat … than those with lower levels” We know that PFOS is correlated with several types of cancer, but we only recently found that “PFOS exposure caused lowered levels of a ketogenic enzyme in the intestines called HMGCS2, which plays an important preventive role in several cancers”

Luckily, we already know of three main ways to get rid of PFASs.

There’s thermal decomposition, where we cook it above 1000 degrees Celsius (1832 Fahrenheit). But that’s seriously energy intensive and hard to scale. There’s photocatalysis, which uses a catalyst that can be activated by light. But most PFAS removal has to be done in wastewater, which is cloudy, and prevents light from reaching every part.

Still, a team in Germany figured out a way to make PFOS completely break down in 24 hours with photocatalysis. Another group figured out how to break down PFAS by 36% in 30 minutes using, and I wish I was kidding, bubbles. Yet another group, not to be outdone by the Bubble Crew, figured out how to do it with glitter and high-pitched noises.

Finally, there’s adsorption, where you use a kind of sponge to soak up the PFAS. A University of British Columbia group found a way to “eliminate up to 90% of forever chemicals in water in as little as three hours” using an activated carbon filter with a twist

Activated carbon technology is not new or complex. There are no bubbles or glitter. It’s just boring, old fashioned, hundreds of years old technology.

So how well does activated carbon work? Previously, we covered how pitcher filters are fine, but can never hold a candle to an undersink filter. And yet, a pitcher filter with an activated carbon component removed 81%–96% of the PFASs in a given sample. So it shouldn't be a surprise that adding pressure to an activated carbon filter, should give you better results than just a pitcher filter.

Hopefully you now have a better understanding of what PFASs are, how we’re still learning about them, and the simplest way to remove them from your drinking water. If you're concerned about PFAS contamination in your home, consider investing in an undersink filter from The Right Filter.

At least until bubble-glitter filters become commercially available.

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