US EPA Proposal to list 9 PFAS as Hazardous Constituents under RCRA

PFAS, also known as “forever chemicals,” are a class of manufactured chemicals that have been widely used in many industrial and consumer products since the 1940s, and they are still being used today. PFAS have been or are currently being manufactured for a variety of different uses, ranging from adhesives, coatings for clothes and furniture, fire-fighting foam, and other uses. Scientific studies show that exposure to some PFAS in the environment is linked to harmful health effects in humans and animals.

In June 2021, the Governor of New Mexico petitioned EPA to list PFAS, either individually or as a class, as hazardous wastes under RCRA.  New Mexico’s petition incorporated two earlier petitions submitted to EPA by reference, which also requested EPA to regulate PFAS under RCRA. EPA acted upon the Governor of New Mexico’s petition with a letter in October 2021.  EPA indicated in the letter that it would initiate a rulemaking process to propose adding PFOA, PFOS, PFBS and GenX (Hexafluoropropylene oxide-dimer acid) as RCRA hazardous constituents under 40 CFR Part 261 Appendix VIII. Listing as a hazardous constituent is a building block for any future work to regulate PFAS as a RCRA listed hazardous waste.

On February 8, 2024, US EPA proposed changes to the Resource Conservation and Recovery Act (RCRA) regulations by adding nine particular per- and polyfluoroalkyl compounds, their salts, and their structural isomers, to its list of hazardous constituents in Title 40 of the Code of Federal Regulations Part 261 Appendix VIII. 

Proposed list of 9 PFAS:-

1. Perfluorooctanoic acid.
2. Perfluorooctanesulfonic acid.
3. Perfluorobutanesulfonic acid.
4. Hexafluoropropylene oxide-dimer acid.
5. Perfluorononanoic acid.
6. Perfluorohexane Sulfonic acid.
7. Perfluorodecanoic acid.
8. Perfluorohexanoic acid.
9. Perfluorobutanoic acid.

1. Perfluorooctanoic acid (PFOA):- PFOA is an eight-carbon molecule with seven fully fluorinated carbon atoms and one carboxylic acid functional group. It has been used as a processing aid to produce fluoropolymers and has been found in cleaning agents, waxes, aqueous film-forming foam(AFFF), and other products.’

2. Perfluorooctanesulfonic acid (PFOS):- PFOS is a fully fluorinated eight-carbon molecule with one sulfonic acid functional group. It has been used in aqueous film-forming foam(AFFF), in surface treatments of textiles to provide oil and water resistance, in metal plating, and other uses and industries.

3. Perfluorobutanesulfonic acid (PFBS):- PFBS is a fully fluorinated four-carbon molecule with one sulfonic acid group. It has been used as a replacement for PFOS and has been used in the manufacture of paints and cleaning agents, metal plating, AFFF, to provide oil and water resistance, and other uses and industries.

4. Hexafluoropropylene oxide-dimer acid (HFPO-DA or GenX):- HFPO-DA is a six-carbon molecule consisting of five fully fluorinated carbon atoms, one either functional group, and one carboxylic acid functional group. HFPO-DA is a chemical associated with GenX processing aid technology used to make fluoropolymers without the use of PFOA.

5. Perfluorononanoic acid (PFNA):- PFNA is a nine-carbon molecule with eight fully fluorinated carbon atoms and one carboxylic acid functional group. It has been used as a processing aid to produce fluoropolymers and has been used or found in metal plating, cleaning agents, waxes, AFFF, energetic materials, and other products

6. Perfluorohexane Sulfonic acid (PFHxS):- PFHxS is a fully fluorinated six-carbon molecule with one sulfonic acid functional group. It has been used in AFFF, in surface treatments of textiles to provide oil and water resistance, in metal plating and other uses and industries.

7. Perfluorodecanoic acid (PFDA):- PFDA is a ten-carbon molecule with nine fully fluorinated carbon atoms and a carboxylic acid functional group. It has been used as a processing aid to produce fluoropolymers and has been used or found in metal plating, cleaning agents, waxes, AFFF, energetic materials, and other products. 

8. Perfluorohexanoic acid (PFHxA):- PFHxA is a six-carbon molecule with five fully fluorinated atoms and a carboxylic acid functional group. It has been used or found in metal plating solutions, cleaning agents, waxes, AFFF and other products.

9. Perfluorobutanoic acid (PFBA):- PFBA is a four-carbon molecule with three fully fluorinated atoms and one carboxylic acid functional group. It has been used or found in metal plating solutions, cleaning agents, waxes, AFFF, energetic materials and other products.

Scientific research must demonstrate that a chemical has poisonous, carcinogenic, mutagenic, or teratogenic effects on people or other living things in order for it to be classified as a hazardous ingredient under the RCRA. The EPA concluded that these nine PFAS compounds meet the requirements to be listed as an RCRA hazardous ingredient after reviewing the toxicity and epidemiology data for these substances.

By enhancing its capacity to handle PFAS pollution under the RCRA Corrective Action Programme, the cleanup programme, the EPA is attempting to safeguard communities with this plan. This modification would make it easier to take further remedial action to deal with PFAS leaks at RCRA hazardous waste treatment, storage, and disposal sites. The set of cradle to grave management controls connected to an RCRA hazardous waste would not be necessary.

EPA has certified that this proposed rule will not have a significant impact on a substantial number of small entities. However, EPA is also specifically soliciting comments on its conclusion that the proposed rule would not result in any additional costs, including to small entities.