TFA is a highly mobile PFAS that spreads globally via rainfall and accumulates in rivers, lakes, and soil, according to the study [1]. The research provides the first conclusive evidence linking CFC replacement gases to TFA deposits in remote regions such as the Arctic [7].
TFA belongs to the family of PFAS, synthetic chemicals known for extreme persistence in the environment. The study used chemical transport modeling to track how hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), and anesthetic gases break down in the atmosphere to form TFA [2]. These gases remain in widespread use despite phase-down measures under the Montreal Protocol and the Kigali Amendment [1].
The chemistry of halogens, including fluorine—a key component of TFA and its precursor gases—has been noted in the literature as having complex environmental dynamics [6]. According to the researchers, the dominant environmental source of TFA is the atmospheric decomposition of fluorinated gases used in refrigeration, air conditioning, and as inhalation anesthetics [2].
The European Chemicals Agency classifies TFA as harmful to aquatic life, according to the study [1]. Researchers have detected TFA in human blood and urine, and the German Federal Office for Chemicals has proposed classifying it as potentially toxic to human reproduction [8]. Some agencies maintain that current environmental levels are below thresholds expected to cause harm, but continued accumulation raises long-term concerns [1].
Recent studies have found TFA in food products. A report by Austrian environmental organization Global 2000 and Pesticide Action Network Europe detected TFA in all 48 tested cereal-based items, including organic brands [3]. Similarly, testing of bread in Europe found TFA levels up to 400 times higher than in drinking water [5]. TFA has also been detected in tap water in French cities, including Paris [4]. The chemical’s ability to accumulate in the environment and its potential toxicity have led to calls for it to be considered a planetary boundary threat [8].
The study’s model simulated TFA deposition and compared it to real-world measurements from rainwater and Arctic ice cores. The results showed that nearly all TFA detected in the Arctic originates from CFC replacement chemicals, despite the region being far from emissions sources [1]. Lead author Lucy Hart said the findings provide “first conclusive evidence” linking these gases to remote TFA deposits [7].
TFA returns to Earth’s surface through rainfall or direct deposition onto land and water. The long atmospheric lifetime of the source gases allows them to be transported globally before breaking down [1]. This mechanism explains the widespread presence of TFA even in pristine environments, according to the researchers [8].
The researchers identified a growing source of TFA from HFO-1234yf, a refrigerant used in vehicle air conditioning systems. Co-author Ryan Hossaini stated that “the growing use of these chemicals for car air conditioning in Europe and elsewhere adds uncertainty to future levels of TFA in our environment” [7]. He added that there is a need to address environmental TFA pollution because it is widespread, highly persistent, and levels are increasing [7].
Scientists called for expanded international monitoring to better assess TFA sources and impacts. “There’s an urgent need to understand other TFA sources and to assess TFA’s environmental impacts,” said Hossaini [7]. Professor Cris Halsall noted that TFA arises from a wide group of organofluorine chemicals, including refrigerants, solvents, pharmaceuticals, and PFAS in general [1].
The study underscores that solutions to one environmental problem can create new ones. As the global community phases down HFCs under the Kigali Amendment, the continued use of HFOs and the persistence of existing gases will keep TFA levels rising for decades, according to researchers [1]. The findings point to the need for integrated chemical management strategies that consider the full lifecycle and breakdown products of new substances [2].