Unlike the U.S. EPA, Maine defines PFAS to include some fluorinated refrigerants, including TFA-producing HFO-1234yf.

The U.S. Environmental Protection Agency (EPA) does not consider f-gases or their degradation product trifluoroacetic acid (TFA) to be part of PFAS (per- and polyfluoroalkyl substances), or forever chemicals, a category of environmental pollutants.

However, the state of Maine takes a different view. It plans to ban the sale of certain refrigerants, foams and aerosol propellants as well as cooling, heating, ventilation, air-conditioning and refrigeration equipment that contain “intentionally added PFAS” beginning in 2040.

The bans fall under Maine’s updated PFAS law, which went into effect in August 2024. The law is one of the most aggressive state PFAS laws in the U.S., with prohibitions of PFAS in a wide range of consumer products starting in 2026, including cleaning products, cookware and cosmetics. It is the only U.S. state law known to schedule a ban for PFAS in HVAC&R products. The EU is in the process of considering PFAS restrictions that could include refrigerants.

Notably, Maine, like 22 other states, defines PFAS as “substances that include any member of the class of fluorinated organic chemicals containing at least one fully fluorinated carbon atom.” This definition, endorsed by more than 150 scientists, covers certain f-gases, including HFCs and HFOs, as well as TFA.  The “at least one fully fluorinated carbon atom” definition is nearly identical to one developed for the OECD (Organisation for Economic Co-operation and Development) in 2021 and used around the world.

However, Maine’s PFAS definition is not being used by the EPA’s Office of Pollution Prevention and Toxics (OPPT), which has taken a number of approaches in recent years. Most recently, in its PFAS reporting rule, the EPA acknowledged that its definition “does not include substances that only have a single fluorinated carbon.”

Intentionally added PFAS

Maine further defines “intentionally added PFAS” as “PFAS added to a product or one of its product components to provide a specific characteristic, appearance or quality or to perform a specific function.” In addition to refrigerants, small amounts of PFAS are found in HVAC&R equipment in components like O-rings, the seal of the expansion valve and in electronics.

Products containing intentionally added PFAS also include products that consist solely of PFAS under the law, meaning certain HFC and HFO refrigerants by themselves would be covered by the law, including HFC-125, HFC-134a, HFC-143a, HFO-1234yf, HFO-1234ze(E), HFO-1336mzz(Z) and HFO-1336mzz(E). It would not cover HFC-32, which is not a PFAS.

Maine’s 2024 PFAS law also applies to HVAC&R equipment sold “in a fluorinated container or in a container that otherwise contains intentionally added PFAS.” However, the prohibition does not apply to products sold “in used condition” or to “parts and other servicing needs for cooling, heating, ventilation, air-conditioning or refrigeration equipment, including refrigerants used in the servicing of such equipment” as long as the refrigerant is approved under the EPA’s Significant New Alternatives Policy (SNAP) program.

Maine’s updated PFAS law also establishes a “PFAS source reduction program” based on available funding. This will aim at reducing “the presence of PFAS in discharges to air, water and land by encouraging the use of safer alternatives to, and the proper management of materials containing, PFAS.” The program may include information targeted to industrial or commercial users of PFAS and the education of the general public. It would support the adoption of natural refrigerants as an alternative to f-gases.

Maine has established a PFAS in Products program that can address questions about the new law at PFASproducts@Maine.gov.

TFA Not Covered as Byproduct

Maine’s law notes that Intentionally added PFAS includes “any degradation byproducts serving a functional purpose or technical effect within the product or its components.” That would not apply to TFA, which forms in the atmosphere from the oxidation of certain f-gases, particularly HFO-1234yf, and comes down to earth in rainfall. However, HFO-1234yf itself would be covered, thereby preventing the formation of TFA in the atmosphere.

TFA, which is used in industrial and pharmaceutical applications, may be prohibited as a PFAS by the Maine law in 2032, when bans of PFAS not already banned (except for refrigerants and HVAC&R equipment) go into effect. “The law does not provide exemptions for any specific categories of PFAS,” said Blazka Zgec, Environmental Specialist in the Office of the Commissioner for the Maine Department of Environmental Protection (DEP). But proliferation of TFA in the environment – in surface water, drinking water, soil, human blood serum, plants and plant-based foods – stems mostly from the breakdown of refrigerants and other products like certain pesticides, pharmaceuticals and other PFAS. Last August, the Bangor Daily News, a major Maine publication, reported on the growth of TFA in the environment, noting that neither Maine nor the federal government is regulating or testing for TFA.

TFA’s toxicity is still being assessed but one study has called it a “planetary boundary threat” and Germany has linked it to reproductive toxicity.

The chemical industry addressed the environmental deposition of TFA in an October 2021 study funded by the Global Forum for Advanced Climate Technologies (globalFACT), which represents f-gas producers Chemours, Honeywell, Arkema and Koura. The study concluded that “with the current knowledge of the effects of TFA on humans and ecosystems, the projected emissions through 2040 would not be detrimental.” But the study also acknowledged that “the major uncertainty in the knowledge of the TFA concentrations and their spatial distributions is due to uncertainties in the future projected emissions.

Currently Unavoidable Use

The Maine DEP provides exemptions for any products “for which it has determined the use of PFAS in the product is a currently unavoidable use (CUU)” meaning it is “essential for health, safety or the functioning of society and for which alternatives are not reasonably available. The time period of the exemption is either five years from the date the state rules the use is unavoidable, or five years of the date of prohibition (January 1, 2040, for refrigerants and refrigerant-based equipment), whichever provides a longer period of exemption.

In August 2024, Maine also released a “Concept Draft Language for PFAS in Products Rule” (Chapter 90) that provides the requirements for CUU proposals that would be applied to upcoming sales prohibitions. Under the concept draft the Maine DEP will only consider CUU proposals submitted between 18 and 36 months in advance of an applicable sales prohibition. For refrigerants and refrigerant-based equipment that would be between January 1, 2037 and June 30, 2038.

The concept draft rule also says that beginning January 1, 2032, manufacturers with greater than 100 employees that make exempted CUU products would be required to report information about the product, such as the amount of PFAS in the product and an estimate of the total number of units of the product sold annually in the state or nationally. This requirement was originally set for January 1, 2025. There will be fees for manufacturers that are covered by a CUU determination.

Rulemaking for the concept draft rule is taking place through the winter of 2025. Public comments may be submitted through January 28, 2025, by email at rulecomments.dep@maine.gov. There will be a public hearing on the rule on January 16, 2025, 9:00 am, Deering Building, Room 101, 90 Blossom Lane (Use Main Entrance, D1), Augusta, Maine.

“The law does not provide exemptions for any specific categories of PFAS.”

Blazka Zgec, Environmental Specialist in the Office of the Commissioner for the Maine Department of Environmental Protection