HSE Launches Consultation on Classification of AGC's PFOA Replacement Chemical
The Health and Safety Executive has launched a public consultation (reference GBCLP 009) on the mandatory classification of EEA-NH4 — the PFAS chemical currently discharged from AGC's Hillhouse site into the River Wyre at approximately 793 kg per year. The proposed classifications include Category 1B reprotoxic and Category 2 carcinogen. The consultation closes 1 May 2026.
The Health and Safety Executive (HSE) has launched a public consultation on the mandatory classification and labelling of EEA-NH4 (ammonium difluoro-[1,1,2,2-tetrafluoro-2-(pentafluoroethoxy)-ethoxy]-acetate, CAS number 908020-52-0) under GB CLP regulations.
The consultation is listed as reference GBCLP 009 on the HSE Citizen Space consultation platform. It closes on 1 May 2026.
What Is EEA-NH4?
EEA-NH4 is a per- and polyfluoroalkyl substance (PFAS) used as a polymerisation aid in the manufacture of fluoropolymers such as PTFE. It is a member of the class of perfluoroether carboxylic acids (PFECAs).
At the Hillhouse site, EEA-NH4 is imported from Japan by AGC Chemicals Europe Ltd and used as a processing chemical in PTFE manufacturing. It is the chemical that replaced PFOA — perfluorooctanoic acid — when AGC voluntarily discontinued PFOA use around 2012.
The Environment Agency’s 2023 risk evaluation for EEA-NH4 estimated that approximately 793 kg per year of EEA-NH4 was being discharged from the Hillhouse site to the River Wyre at the time of that assessment. The same evaluation classified EEA-NH4 as likely very persistent (vP), toxic, and of unclear bioaccumulation status — meeting criteria for designation as persistent, mobile and toxic (PMT) and very persistent and very mobile (vPvM). These are categories indicating risk to groundwater and potential for long-distance environmental transport.
HSE’s Proposed Classifications
Based on rat study data, HSE has proposed two classifications for EEA-NH4:
Category 1B Reprotoxic — “May damage the unborn child”
This classification is supported by adverse effects on reproductive development observed in two separate rat studies. Category 1B is used where there is a presumption that a substance is a human reproductive toxicant, based on animal evidence.
Category 2 Carcinogen — “Suspected of causing cancer”
HSE describes this as a borderline case. Rat studies at 52 and 104 weeks showed:
- Liver effects in male rats at 4 mg/kg bodyweight/day
- Kidney effects in both sexes at 20 mg/kg bodyweight/day
A 28-day study also found statistically significant increases in liver weight in male rats at the highest dose tested, which HSE considers “of concern.”
HSE’s conclusion is that the combined liver and kidney findings support Category 2 carcinogen classification, while acknowledging the borderline nature of the evidence.
Context: The Replacement Chemical
PFOA was widely used in fluoropolymer manufacturing before its hazardous properties — including carcinogenicity and persistence — led to international regulatory restrictions. AGC’s own submission to the Parliamentary Environmental Audit Committee (May 2025) states that the company “voluntarily discontinued the manufacture and sale of PFOA prior to its inclusion in international regulatory frameworks.”
EEA-NH4 was part of the fluoropolymer industry’s transition away from PFOA. It was developed in part for having a shorter fluorinated chain than PFOA, which was expected to reduce environmental persistence and toxicity concerns.
The HSE consultation is the first formal classification process under GB CLP for EEA-NH4. If the proposed classifications are adopted following the consultation, EEA-NH4 will be designated in GB regulatory databases as a suspected carcinogen that may damage the unborn child. That classification would be relevant to assessments of occupational exposure, environmental permitting, and product risk characterisation.
Independent peer-reviewed research (Cousins, Dalmijn et al., Environmental Science & Technology, 2025) reported the first measured quantification of EEA-NH4 in any environmental matrix — with concentrations of up to 1,744 ng/L in surface water near the Hillhouse outfall.
How to Respond
The HSE consultation is open to responses from members of the public, businesses, and organisations. It is accessible via the HSE Citizen Space consultation platform: https://consultations.hse.gov.uk. Search for reference GBCLP 009.
The consultation closes on 1 May 2026.
Sources: HSE GB CLP Consultation GBCLP 009 — Article 37A mandatory classification and labelling proposal for ammonium difluoro-[1,1,2,2-tetrafluoro-2-(pentafluoroethoxy)-ethoxy]-acetate (EEA-NH4), CAS 908020-52-0. HSE Citizen Space: https://consultations.hse.gov.uk. Environment Agency Risk Evaluation for EEA-NH4, 2023. Cousins, Dalmijn et al., Environmental Science & Technology, 2025 (PMC12312159, DOI: 10.1021/acs.est.5c07856). AGC Chemicals Europe Parliamentary Written Evidence PFAS0059, Environmental Audit Committee, May 2025.