With new research recently published in the Environmental Science & Technology Letters on the continuing issue of PFAS laden Fire Gear. We reach out to Professor Graham Peaslee of Notre Dame, who co-authored the new paper, for a Question and Answer Session. His answers are unedited.
1. Due to the technical nature of the published study. How would you summarize the outcome in a one-minute elevator speech?
This is an extensive and complicated experimental study into what are the sources of fluorine found in new turnout gear…it is highly technical and represents a thorough study into where this fluorine originates in the gear. First, and foremost, the fluorine is coming from PFAS used in the manufacture of the gear. Every item studied had PFAS present, and often lots of it. As had been found earlier, the outer layer had so-called “side-chain” polymeric PFAS and these types of polymers were further investigated in this article. The moisture barrier was found to be a Teflon layer (a polymeric PFAS) mixed with other polymers. The amounts of identified PFAS found represent only a small fraction of the total fluorine used in the manufacture of turnout gear, which means most of the fluorine is locked up in the polymers, but even in this new gear there were free PFAS found in each layer as well (around 0.2 ppm), which represents an exposure risk to anybody in contact with the gear. More importantly, this study investigated volatile PFAS in turnout gear for the first time – these are molecules that more readily turn into gases – and found over 20 ppm in the gear (especially in the moisture barrier), and this could represent a much higher exposure risk.
2. How does this new study compare to your initial study? What were the similarities? What were the differences?
This study does confirm much of what we saw in the 2020 study of new and used turnout gear…in that the side-chain fluoropolymers were observed on the outer layer, and Teflon was found in the moisture barrier. The quantities of the free PFAS are similar, but lower in this study by about a factor of two, which could be because these are all new gear samples, while the earlier study had a mix of new and old gear, or it could be related to the type of extraction we used to remove the free PFAS. We used methanol with a base added to it, and this study just used methanol. The pure methanol will more closely represent what is available now to wash out of the gear, while the basic methanol will represent what is likely to come off the gear over time. Thus the two studies are encouragingly similar in these results. What is new about this recent study is that volatile PFAS were measured as well (which wasn’t done in the 2020 study) and more than 100 times more free PFAS was found in the volatile component. Since these PFAS will be even more available under environmental conditions firefighters experience, this may represent a more significant exposure risk than the earlier study. The conclusions of both studies are similar: more research is needed into these chemicals on the gear.
3. Was this study intended to qualify your initial study? Does this peer-reviewed study validate the initial study or complicate the result of the initial study?
No, this was an independent scientific study led by one of the leading PFAS research labs in the world – Jennifer Field’s lab at Oregon State University. She courteously invited me to contribute some analyses to this paper because she wanted to compare her results to our measurements on the same samples – to help tie the results to the earlier work. In my mind, this is a much more thorough study than our initial work but it does validate the most important points of the earlier paper in that there are measurable amounts of PFAS present in all layers of the gear – an this does represent an exposure risk to the firefighters who wear the gear. The complication of finding different types of PFAS at 100-fold higher concentrations is scary, but an important contribution to understanding how to evaluate the risks of exposure to PFAS.
4. Can you share any details on the method used compared to the method you used in the original study?
Yes, the identification of the individual PFAS in the original study was performed by a good commercial laboratory, while the individual PFAS in this study was done in the top academic laboratory in the world – so there were more PFAS included in this study. The instruments used are identical however and the conclusions about the amounts of PFAS found are similar. More importantly, a different experimental method to detect volatile PFAS was used in this study – and they were found in abundance in the moisture barrier. In addition of our original method for screening for total fluorine, several other new methods of total fluorine were used in this study as well, and they confirm the measurements well.
5. If you could bullet point some major takeaways from this study what would those bullet points be?
As was reported in the earlier study, PFAS are found in all layers of the turnout gear and this represents an exposure risk to firefighters. We do not know how much of an exposure risk yet, but if we can make gear without PFAS, this risk would be reduced. Also, there were many more PFAS observed in the moisture barrier (the Teflon layer) that are volatile, and could transfer out of the garment more readily – which represents a new exposure risk we didn’t have the tools to observe in the earlier study. This highlights the need to switch away from PFAS-based technologies for the moisture barrier as well as the rest of the gear.
6. With all of the studies being published on this topic, two Fire Gear PFAS studies, a Fire station dust study, blood serum study, skin absorption study… Is significant evidence beginning to pile up that PFAS is an occupational exposure that poses a significant risk to firefighter health?
You are correct in that there are a lot of studies beginning to come out. The original turnout gear paper showed that PFAS were used in the making of the gear, and that it comes off the gear over time. This paper confirmed that it was there even on new gear still, and identified a previously unknown source of volatile PFAS on the moisture barrier. All of these chemicals pose a risk of PFAS exposure to those who wear the gear. In addition, the discovery of PFAS in fire station dust (published in between these two studies) shows that it is coming off the gear where it is stored and is another way in which these chemicals could accidentally enter the body. Finally, there are several studies that now show elevated concentrations of PFAS in the blood sera of firefighters, which was previously thought to be entirely due to AFFF exposure but may indeed be a combination of exposures. Over the next few years several important studies on dermal sorption of PFAS and revised exposure assessments will be produced that will help quantify how much of a risk these chemicals in the gear may pose to the firefighter who wears the gear.
7. What comes next?
I hope these articles will get more of the scientific community to study this problem – especially from an exposure science perspective – as this will help define how much of a risk these textile sources of PFAS represent to the typical user of the gear. Everybody should continue to wear their gear to keep themselves safe occupationally – this gear is designed to reduce risk in a fire situation – but away from the times when it is needed, policies should be refined to reduce exposure to the gear for now. Similarly, manufacturing efforts to switch to safer NFPA-1971 compliant turnout gear without PFAS should be encouraged widely. Also, this study will renew our focus on why the moisture barrier needs to be made out of a fluoropolymer at all? In terms of providing a moisture barrier, several other polymers will work, and UV light resistance seems to be an odd test to use on a layer that never sees sunlight. Finally, more research is needed into the “data gaps” identified in this most recent publication, which include things like: how many of these PFAS can be absorbed through the skin under what conditions? Or how important is the dust inhalation or ingestion route of exposure for firefighters? Or how many of these PFAS continue to be released from the gear over time – both while in use, or when the gear is finally disposed of? Also, the effects of high-temperature and laundering on PFAS release has not been fully investigated on this gear. We will keep working on the issues, and it is good to see more scientists getting involved and helping to highlight where more answers are needed.
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