Egg Testing Near Hillhouse: PFOS Dominant, PFNA Above EU Limits — and Questions About Source

The PFAS4 Panel

EFSA’s PFAS4 panel — the four compounds assessed together for food safety purposes — consists of:

• PFOS (perfluorooctane sulfonic acid)
• PFOA (perfluorooctanoic acid)
• PFNA (perfluorononanoic acid)
• PFHxS (perfluorohexane sulfonic acid)

EU Regulation 2022/2388 sets maximum levels for the PFAS4 group in food, including eggs. The tolerable weekly intake established by EFSA is based on the combined sum of these four compounds.

What the Egg Testing Near Hillhouse Found

Egg testing conducted in proximity to the Hillhouse site [UNVERIFIED — full dataset, collection dates, and precise locations not confirmed against primary source] detected:

1. PFOS as the dominant compound — exceeding the concentrations of other PFAS4 components
2. PFNA above EU maximum limits for the PFAS4 sum
3. PFOA present — the compound with an established connection to fluoropolymer manufacturing of the type conducted at Hillhouse
4. PFHxS present

The source question: PFOA has documented pathways to AGC Chemicals Europe’s Hillhouse operations — the site historically used PFOA in fluoropolymer manufacturing and its successor compound EEA-NH4 is currently permitted. However, PFOS, PFNA, and PFHxS do not have documented connections to AGC’s permitted operations.

Why These Compounds Were Tested

The EFSA PFAS4 panel is standard — it is the regulatory framework for food PFAS monitoring across the EU and, through UK retained law, in Great Britain. When testing is commissioned under this framework, all four compounds are measured regardless of whether the local source is expected to produce them.

This means the egg testing would have detected PFOS, PFNA, and PFHxS even if the only purpose was to check for PFOA from the Hillhouse site. The presence of three compounds without a documented local source was an incidental finding of the standard panel.

What This Does and Does Not Establish

What the data shows (subject to verification of primary source):

• PFAS contamination is present in eggs in proximity to Hillhouse at levels of concern
• The dominant compound is PFOS, not PFOA
• At least one compound (PFNA) is present above EU food safety limits
• Three of four detected compounds lack documented connection to AGC Chemicals Europe

What this does not establish:

• The source of PFOS, PFNA, and PFHxS at this location
• Whether AGC’s operations are responsible for any of the non-PFOA compounds
• Whether the contamination is from Hillhouse specifically or other local sources
• Whether these findings have been reported to the FSA or EA

The Unanswered Source Question

PFOS was globally phased out under the Stockholm Convention by 2009. Its presence in the environment today typically reflects historical contamination — industrial sites, fire-fighting foam (AFFF), or legacy disposal. The Hillhouse area has a long industrial history and the Hillhouse site itself has had multiple occupants and uses.

The Part 2A assessment of the Hillhouse site produced mass spectrometry data. Whether that data was examined for a full PFAS panel — beyond the specific compounds named in the assessment scope — has not been confirmed. [UNVERIFIED]

The Regulatory Gap

PFNA above EU limits in eggs constitutes a food safety exceedance. The responsible authority for food contamination in England is the Food Standards Agency (FSA). Whether the FSA was notified of these findings, and what action was taken, is not known. [UNVERIFIED — FOI request to FSA recommended.]

[UNVERIFIED] items require confirmation against primary documents. The PFAS4 egg monitoring data referenced in this post needs to be confirmed against the primary laboratory report. This post will be updated when the primary source is obtained. See the Sources page for citation status.