Scientists from Lancaster University have conducted the first assessment of the accumulated pollutant in the world. Their analysis showed that from 2000 to 2022, approximately 335,500 tons of trifluoroacetic acid (TFA) fell to the Earth's surface, a consequence of the replacement of HFCs and the use of certain anesthetic gases.
The study, published in the journal Geophysical Research Letters, emphasizes that the pollution situation is far from resolved. Many HFC substitutes can remain in the atmosphere for decades, leading to the continued influx of TFA into the environment. Researchers suggest that the peak annual production level of TFA may be reached between 2025 and 2100.
TFA is formed as a result of the breakdown in the atmosphere of hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs), which are widely used in refrigerators and as inhalation anesthetics. Despite a gradual reduction in their use (in accordance with the Montreal Protocol and the Kigali Amendment), their concentration in the atmosphere continues to rise.
Trifluoroacetic acid belongs to the class of per- and polyfluoroalkyl substances (PFAS), which are known for their incredible resistance to natural degradation and can remain in the ecosystem for extended periods.
According to the European Chemicals Agency, TFA poses a danger to aquatic organisms. This chemical has also been found in human blood and urine samples, leading the Federal Institute for Occupational Safety and Health in Germany to recommend classifying TFA as potentially toxic to reproduction.
"Our results show that HFC substitutes are likely the main source of TFA in the atmosphere," noted Lucy Hart, the lead author of the study. "This underscores the need to consider broader risks when replacing harmful chemicals."
The study data indicate that nearly all TFA found in the Arctic region originates from HFC substitutes, despite the region's remoteness from major emission sources. "Our results convincingly confirm for the first time that almost all TFA deposits in Arctic ice cores can be explained by these gases," explained Hart.
Furthermore, outside polar latitudes, modeling shows that HFO-1234yf, used in automotive air conditioning systems, is becoming a significant and likely growing source of atmospheric TFA.
"The increasing levels of TFA from fluorinated gases raise serious concerns. Although the use of HFCs is gradually decreasing, this source of TFA will remain relevant for decades. A deep understanding of other sources of TFA and their impact on the environment is necessary," added Professor Ryan Hosseini.
