Air and rain samples in Detroit show high levels of TFA ‘forever chemical’

Rain and air samples collected in metro Detroit that researchers checked for toxic PFAS “forever chemicals” showed the highest levels of TFA, an alarming finding because the compound is a potent greenhouse gas and more toxic than previously thought, but not well-studied.

While PFAS are a chemical class known to be ubiquitous in the environment, the new research is part of growing evidence around the globe that points to TFA, commonly used in refrigeration, air conditioning and clean energy technology, accumulating at much higher levels than other well-studied compounds.

Industry is scaling up its use of TFA, or chemicals that turn into it once in the environment, claiming that it is a safe and nontoxic replacement to older greenhouse gases used in refrigeration, but TFA’s climate impacts to some degree negate the benefits of clean energy technology.

About 60% of all PFAS manufactured from 2019-2022 were fluorinated gas that turns into TFA in the environment and the research comes as industry is mounting a campaign to thwart regulation.

“It is an unregulated area that is getting a lot more attention and these industries are trying to figure out how to avoid that,” said Erica Bloom, a lead author on the paper with the ecology center in Michigan.

PFAS are a class of about 15,000 chemicals typically used to make products that resist water, stains and heat. They are called “forever chemicals” because they do not naturally break down; they accumulate and are linked to cancer, kidney disease, liver problems, immune disorders, birth defects and other serious health problems.

TFA is largely produced when fluorinated PFAS gas, or f-gases, break down in the atmosphere. The compound has a life of around 1,000 years – about as long as carbon dioxide. Its toxicity is far less understood than most common PFAS compounds, though recent research shows reproductive system harms similar to other forever chemicals.

The compound is especially problematic because it cannot be filtered out of water with traditional filtration methods, and it easily moves throughout the environment via water or in the atmosphere.

The Ecology Centers found high TFA levels in rain samples in Ann Arbor, which is not a heavily industrialized area, as well as Dearborn and Detroit, which are heavy manufacturing areas. The similar levels in all three suggest the chemicals are moving through the atmosphere and not solely from local industry, Bloom said.

All samples also contained PFOS and PFOA, two of the most common and highly toxic PFAS compounds. The environmental protection agency has found virtually no level of exposure to the two compounds in drinking water is safe and the levels found in Dearborn and Detroit exceed the federal limit.

Industry and the military is pushing to exclude TFA from the definition of PFAS so the chemicals face less scrutiny and oversight. The compounds have been found at concerning levels in the wastewater in chemical giant Chemours’ North Carolina plant. However, at least some divisions within the EPA do not consider TFA a PFAS, and are not requiring industry to monitor for it.

In the Netherlands, Chemours was effectively forced by the government to shut down part of its PFAS production plant because the company could not control TFA pollution, while the UK, Germany and Denmark are considering bans on the chemical.