The transition to refrigerants and blowing agents using F-gases with lower global warming potential may have reduced climate impacts but the inconvenient truth is that these F-gases are themselves or degrade into mobile and highly persistent PFAS, that are rapidly building up in rainwater, groundwater, ocean water, human blood and vegetation – with no effective remediation. The good news is climate friendly and F-gas free natural alternatives are widely available which is why the EU Restriction on PFAS must be urgently adopted to hasten the transition away from F-gases to natural, PFAS-free alternatives. 

F-gases are used in many applications including the electricity grid for insulation, in refrigeration, air conditioning, heat pumps, and even anaesthetics. Other uses include blowing agents in insulating foam, fire suppressants, and propellants. Of these end-uses, 75% of the volumes go into refrigeration, air conditioning and heat transfer fluids. Besides these end-uses, fluorinated gases are also used in the production of fluoropolymers as feedstock.  

F-gases are a significant climate issue because they trap heat in the Earth’s atmosphere. The global warming potential of F-gases (not all of them being PFAS) is up to 24,300 times worse than CO2 over a 100-year period.1 Emissions to the air occur through leaks, and other irregular releases during manufacturing, use and end of life. 

“F-gases which are PFAS constitute the largest proportion of PFAS by quantity and emissions in Europe, accounting for 63% of all PFAS emissions.2 F-gases are the lowest hanging fruit to minimize PFAS emissions since their substitution with sustainable, favourable and available alternatives is a WIN, WIN, WIN for people, planet and profit.” Christine Luetzkendorf (Policy Advisor F-Gases at DUH, Germany)  

The story of F-gases is a story of regrettable substitution. Climate-damaging F-gases were introduced as ozone-friendly replacements in response to the 1987 Montreal Protocol agreement to phase out CFCs due to their destructive effect on earth’s stratospheric ozone layer. In response to the CFC restriction, the chemical industry introduced hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) as replacements. These gases have respectively very low or no ozone depleting potential but high global warming potential. Through the F-gas regulation, the EU introduced a system to phase down HFCs in 2014, followed by the parties to the Montreal Protocol agreeing to phase-down HFCs in the Kigali Amendment in 2016 on the global level.  

“The F-gas regulation is the most ambitious legislation in the world when it comes to climate wrecking refrigerants and foams and needs to be now taken at the global scale. It represents a major step forward in tackling the climate crisis. We welcome the ban on some PFAS refrigerants, but it is clearly not enough to properly address the continuing problem of PFAS emissions from F-gases: that’s why a complementary restriction of fluorinated gases under REACH regulation is essential to stop the chemical pollution crisis fueled by enormous PFAS emissions from F-gases.”  Davide Sabbadin (Acting Policy Manager for Climate and Energy, EEB) 

As alarm bells rang about the global warming potential of HFCs, the chemical industry produced the next F-gas generation (HFOs) with very low global warming potential, and they have been steadily growing in use from 6% to 24% of total fluorinated gas volumes between 2016 and 2019.3 PFAS producers claim that the use of HFOs in refrigeration is safe and can be responsibly manufactured and used with strict emissions control.4  

But the inconvenient truth is that F-gases are creating widespread, persistent and growing global PFAS pollution. When these gases are released into the air, they degrade to trifluoroacetic acid (TFA), a highly persistent and mobile PFAS. TFA concentrations are now rapidly increasing in rainwater, groundwater and ocean water, and were also detected in vegetation. Since TFA is also widely found in indoor and outdoor dust, as well as in bottled water, it comes as no surprise that TFA is now commonly found in human blood5,6 and urine.7 No other substance has been found in so many environmental media, in these high concentrations and with such a fast increase. TFA is highly persistent and under environmental conditions, there are no known degradation processes, meaning TFA’s lifetime is practically indefinite8. This leads to the assumption that every molecule of TFA we put into the environment now, will remain there for centuries. So the more TFA is produced from F-gas degradation, the more it will build up in the environment for generations to come.  

“My concern is mainly in line with TFA ringing all the alarm bells we had with previous global pollutants that are (still) causing problems, like DDT, ozone depleting chlorofluorocarbons, plastic litter.”  Hans Peter Arp (Professor II at NTNU Trondheim, NO) 

TFA was recently measured as the dominant PFAS in Germany’s drinking water.9 The bad news is that TFA is impossible to remove using standard filtration and remediation technologies.10 Estimated costs to even attempt to remove TFA would run to 200 billion euros per year for industrial wastewater and 38 billion euros per year for drinking water to be cleaned with reverse osmosis, the only one of two techniques that can remove TFA from the water. But it would be almost impossible to clean all drinking and wastewater with this technique as the infrastructure upgrade would not be realistic.11 Time is of the essence to halt more TFA build-up from F-gases because the levels of TFA have already increased 250-fold across Europe12 and this trend will continue unless companies transition to PFAS-free, environmentally preferable alternatives.  

“What people need to realize about TFA are three things. First, its ubiquitous presence in the environment and in human blood is essentially irreversible. Second, TFA concentrations will continue to increase even more rapidly than they have been doing unless action is taken on F-gases and other sources. Third, we cannot assume this will be benign if we are ignorant of impacts, this was the mistake made with CFCs depleting the ozone layer. Once impacts are realized they will be as irreversible as the concentrations of TFA.” Hans Peter Arp (Professor II at NTNU Trondheim, NO) 

The good news is that alternatives, such as natural refrigerants, are on the market and proven to be energy efficient and available at reasonable cost. Natural refrigerants include ammonia, carbon dioxide, and hydrocarbons such as propane and isobutane. These refrigerants are “natural” in that they are based on substances found in nature, rather than synthetic molecules. Inherently, they have properties like higher flammability, but their risks are well manageable, and they are already deployed with safety protocols in place. According to industry analysts, energy efficiency of natural refrigerants can rival or exceed efficiency of fluorinated gases currently used as refrigerants13 and the market share for natural refrigerants is rising steadily.14 

“Safer alternatives to F-gases are available for virtually every application. It’s time to get moving and make the switch to these safer options, which have been around for a long time and proven effective in maintaining performance standards while being eco-friendly.” Jonatan Kleimark, PhD (Senior Chemicals and Business Advisor, ChemSec) 

Based on extensive research and consultation, five member states have proposed an EU Restriction on PFAS including time-limited derogations to F-gases to allow to move this transition forward. They note the high substitution potential for domestic, commercial and industrial refrigeration and the growing acceptance of the use of natural refrigerants in the commercial and industrial markets which indicates that they are cost-competitive with fluorinated gas systems.   

We owe it to future generations to ensure that we advocate for and implement real climate solutions without increasing the PFAS burden on ourselves and future generations. We need to detoxify and decarbonize. Therefore, the EU restriction on PFAS must be successfully adopted as soon as possible in order to have a clear roadmap for phasing out all PFAS, including fluorinated gases. Christine Hermann (Associate Policy Officer for Chemicals, EEB) 

The author, Beverley Thorp, thanks Dolores Romano and Christine Hermann for their contributions to the article.

1 About F-gases. European Commission. https://climate.ec.europa.eu/eu-action/fluorinated-greenhouse-gases/about-f-gases_en 

2 ANNEX XV RESTRICTION REPORT – Per- and polyfluoroalkyl substances (PFASs). Table 1. Estimated annual emissions from the use phase for PFAS manufacture and major PFAS use sectors in 2020. ECHA. 

3 New EU regulation on refrigerant gases can accelerate the PFAS pollution crisis. ChemSec Press Release. 11 Mar 2024. https://chemsec.org/new-eu-regulation-on-refrigerant-gases-can-accelerate-the-pfas-pollution-crisis/ 

4 The World Needs F-gases. Chemours. https://www.chemours.com/en/chemistry-in-action/world-needs-f-gases 

5 Zheng, G. et al. (2023) “Elevated levels of ultrashort-and short-chain perfluoroalkyl acids in US homes and people.” Environmental Science & Technology 57.42 (2023): 15782-15793 

6 Duan, Y., Sun, H., Yao, Y., Meng, Y., & Li, Y. (2020). Distribution of novel and legacy per-/polyfluoroalkyl substances in serum and its associations with two glycemic biomarkers among Chinese adult men and women with normal blood glucose levels. Environment international, 134, 105295. 

7 Zheng, Guomao. Elevated Levels of Ultrashort- and Short-Chain Perfluoroalkyl Acids in US Homes and People. Environ Sci Technol. 2023 Oct 24; 57(42): 15782–15793. doi: 10.1021/acs.est.2c06715  

8 UBA, 2022: Reducing the input of chemicals into waters: trifluoroacetate (TFA) as a persistent and mobile substance with many sources. 

9 Isabelle J. Neuwald et al. (2022) Ultra-Short-Chain PFASs in the Sources of German Drinking Water: Prevalent, Overlooked, Difficult to Remove, and Unregulated. Environ. Sci. Technol. 2022, 56, 10, 6380–6390. May 4, 2022. https://doi.org/10.1021/acs.est.1c07949

10 Behringer et al. (2021) Final Report Persistent degradation products of halogenated blowing agents in the environment 

type, environmental concentrations and fate with particular regard to new halogenated substitutes with low global warming potential, German Environment Agency, 2021, at: 

https://www.umweltbundesamt.de/sites/default/files/medien/5750/publikationen/2021-05-06_texte_73-2021_persistent_degradation_products.pdf, p. 119. and Scheurer M, et al.  “Small, mobile, persistent: Trifluoroacetate in the water cycle – Overlooked sources, pathways, and consequences for drinking water supply, ”Water Resources, 2017 Dec 1;126:460-471 at: https://pubmed.ncbi.nlm.nih.gov/28992593/

11 SETAC Europe 2022 Keynote- Hans Peter H. Arp: Reducing Pollution of PMT Substances to Protect Water. https://www.youtube.com/watch?v=s6_O6MBpE8k&t=1648s  

12 Rayne Holland et al. (2021) Investigation of the Production of Trifluoroacetic Acid from Two Halocarbons, HFC-134a and HFO-1234yf and Its Fates Using a Global Three-Dimensional Chemical Transport Model. ACS Earth Space Chem. 2021, 5, 4, 849–857. March 10, 2021. https://doi.org/10.1021/acsearthspacechem.0c00355 

13 https://cooltechnologies.org 

14 Natural Refrigerants: State of the Industry Report: Commercial and Industrial Refrigeration  in Europe, North America and Japan. 2022 Edition. ATMOsphere. February 2023. 

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