Chlorofluorocarbon Alternatives Linked to Widespread ‘Forever Chemical’ Contamination: Study Findings
Trifluoroacetic acid (TFA) is a breakdown product of various chemicals, including CFC replacement gases utilized in refrigeration and air conditioning, as well as pharmaceuticals, pesticides, solvents, and other persistent chemicals classified as per-and polyfluoroalkyl substances (PFAS).
Over the past two decades, concentrations of TFA have been rising in rainwater, drinking water, soil, and plants. The environmental removal of the thousands of different PFAS chemicals poses significant challenges, as existing technologies are difficult to scale effectively.
If emissions remain unregulated, the projected cost of PFAS removal could reach €100 billion (£86 billion) annually in Europe. Some researchers have identified TFA as a “planetary boundary threat,” indicating that it could disrupt Earth’s natural systems irreparably and jeopardize our survival.
While certain PFAS have been associated with various cancers and fertility issues, the long-term health effects of TFA on humans and wildlife remain largely unknown. However, it has been detected in human blood, breast milk, and urine, and is under consideration for classification as toxic to reproduction by German government agencies.
As our understanding of TFA’s consequences evolves, the urgent need to address increasing TFA pollution becomes clear. A comprehensive understanding of the various sources of TFA and their contributions to environmental levels is essential for informing targeted policy.
Evidence from ice cores can provide insights into these sources. TFA concentrations in Arctic ice over recent decades correlate with their rising usage. In 2020, Canadian researchers proposed that some CFC replacement gases, known to break down into TFA in the atmosphere, could be significant contributors.
These CFC replacements—hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs)—are commonly used in refrigeration, air conditioning, and the production of insulating foams. They eventually leak into the atmosphere, where they can travel vast distances. Upon breaking down, they form TFA and other gases, which can either dissolve in clouds and be washed out through rain or deposit directly from the air onto the Earth’s surface.
Our recent study, published in Geophysical Research Letters, quantified the contributions of these CFC replacements and inhalation anesthetics to global TFA production. We found that approximately one-third of a million tonnes of TFA (335,500 tonnes) has been deposited on the Earth’s surface from these sources between 2000 and 2022.
Although HCFCs and HFCs have been phased down under various amendments to the 1987 Montreal Protocol, TFA production has continued to rise, with peak production projected between 2025 and 2100.
By comparing our model’s TFA amounts to Arctic ice core records, we determined that these sources could explain nearly all TFA deposited in the Arctic. This is particularly concerning, as it underscores the global spread of TFA pollution. Emissions from densely populated northern hemisphere regions can significantly impact remote areas, such as the Arctic, once deemed pristine.
Peak TFA
However, when we compared our model results to rainwater concentrations near emission regions in developed countries with extensive infrastructure, we found that our model could not account for all observed TFA. We speculated that this discrepancy might be due to a refrigerant known as HFO-1234yf, increasingly used in vehicle air conditioning due to its low global warming potential.
While marketed as a sustainable alternative to HFCs, hydrofluoroolefins (HFOs) can produce TFA much more rapidly than HFCs—days for HFOs compared to years for HFCs. This may result in HFOs not traveling as far in the atmosphere before breaking down, leading to more TFA being deposited closer to emission sources.
By incorporating estimated emissions of HFO-1234yf into our model, we were able to significantly bridge the gap between predicted and actual TFA measurements.
Given the uncertainty surrounding HFO emissions, other unknown sources may also contribute to TFA levels observed in rainwater. However, with the increasing use of HFOs, TFA will likely continue to accumulate in the environment. If left unregulated, peak TFA emissions from these sources will extend well into the future.
Considering the risk of irreversible accumulation in the environment, affecting both wildlife and human health, preventing pollution at the source remains the safest and healthiest approach.
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This article is republished from The Conversation under a Creative Commons license. The Conversation is an independent and nonprofit source of news, analysis, and commentary from academic experts. The original article can be accessed here.
Trifluoroacetic acid (TFA) is a breakdown product of various chemicals, including CFC replacement gases utilized in refrigeration and air conditioning, as well as pharmaceuticals, pesticides, solvents, and other persistent chemicals classified as per-and polyfluoroalkyl substances (PFAS).
Over the past two decades, concentrations of TFA have been rising in rainwater, drinking water, soil, and plants. The environmental removal of the thousands of different PFAS chemicals poses significant challenges, as existing technologies are difficult to scale effectively.
If emissions remain unregulated, the projected cost of PFAS removal could reach €100 billion (£86 billion) annually in Europe. Some researchers have identified TFA as a “planetary boundary threat,” indicating that it could disrupt Earth’s natural systems irreparably and jeopardize our survival.
While certain PFAS have been associated with various cancers and fertility issues, the long-term health effects of TFA on humans and wildlife remain largely unknown. However, it has been detected in human blood, breast milk, and urine, and is under consideration for classification as toxic to reproduction by German government agencies.
As our understanding of TFA’s consequences evolves, the urgent need to address increasing TFA pollution becomes clear. A comprehensive understanding of the various sources of TFA and their contributions to environmental levels is essential for informing targeted policy.
Evidence from ice cores can provide insights into these sources. TFA concentrations in Arctic ice over recent decades correlate with their rising usage. In 2020, Canadian researchers proposed that some CFC replacement gases, known to break down into TFA in the atmosphere, could be significant contributors.
These CFC replacements—hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs)—are commonly used in refrigeration, air conditioning, and the production of insulating foams. They eventually leak into the atmosphere, where they can travel vast distances. Upon breaking down, they form TFA and other gases, which can either dissolve in clouds and be washed out through rain or deposit directly from the air onto the Earth’s surface.
Our recent study, published in Geophysical Research Letters, quantified the contributions of these CFC replacements and inhalation anesthetics to global TFA production. We found that approximately one-third of a million tonnes of TFA (335,500 tonnes) has been deposited on the Earth’s surface from these sources between 2000 and 2022.
Although HCFCs and HFCs have been phased down under various amendments to the 1987 Montreal Protocol, TFA production has continued to rise, with peak production projected between 2025 and 2100.
By comparing our model’s TFA amounts to Arctic ice core records, we determined that these sources could explain nearly all TFA deposited in the Arctic. This is particularly concerning, as it underscores the global spread of TFA pollution. Emissions from densely populated northern hemisphere regions can significantly impact remote areas, such as the Arctic, once deemed pristine.
Peak TFA
However, when we compared our model results to rainwater concentrations near emission regions in developed countries with extensive infrastructure, we found that our model could not account for all observed TFA. We speculated that this discrepancy might be due to a refrigerant known as HFO-1234yf, increasingly used in vehicle air conditioning due to its low global warming potential.
While marketed as a sustainable alternative to HFCs, hydrofluoroolefins (HFOs) can produce TFA much more rapidly than HFCs—days for HFOs compared to years for HFCs. This may result in HFOs not traveling as far in the atmosphere before breaking down, leading to more TFA being deposited closer to emission sources.
By incorporating estimated emissions of HFO-1234yf into our model, we were able to significantly bridge the gap between predicted and actual TFA measurements.
Given the uncertainty surrounding HFO emissions, other unknown sources may also contribute to TFA levels observed in rainwater. However, with the increasing use of HFOs, TFA will likely continue to accumulate in the environment. If left unregulated, peak TFA emissions from these sources will extend well into the future.
Considering the risk of irreversible accumulation in the environment, affecting both wildlife and human health, preventing pollution at the source remains the safest and healthiest approach.
Don’t have time to read about climate change as much as you’d like?
Get a weekly roundup in your inbox instead. Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that delves deeper into a specific climate issue. Join the 47,000+ readers who’ve subscribed so far.
This article is republished from The Conversation under a Creative Commons license. The Conversation is an independent and nonprofit source of news, analysis, and commentary from academic experts. The original article can be accessed here.
