Hexamethylene Tetramine
The short version
A formaldehyde-releasing antimicrobial — restricted to traditional provolone cheese in EU.
A preservative that releases formaldehyde, allowed in the EU only for traditional provolone. In 2014 EFSA found the data too limited to set an ADI, which is why we flag it.
Safety profile
JECFA allocated an ADI of 0–0.15 mg/kg body weight (1973). EFSA's 2014 re-evaluation found the toxicity data too limited to derive an ADI. Formaldehyde is classified by IARC as carcinogenic to humans (Group 1) — the food exposure from provolone is well below population-thresholds for the inhalational route that drives the carcinogen classification, but the narrow EU permission reflects the tension.
Sources
- WHO JECFA database — Hexamethylenetetramine (INS 239), evaluation 1973 — World Health Organization / JECFA, 1973. safety: JECFA ADI 0–0.15 mg/kg bw
- EFSA FEEDAP — Safety of hexamethylene tetramine for pigs, poultry, bovines, sheep, goats, rabbits and horses (2020), summarising the 2014 ANS re-evaluation of E 239 — European Food Safety Authority (EFSA Journal), 2020. safety: EFSA 2014 could not derive an ADI
- EU — Regulation (EC) No 1333/2008 on food additives, consolidated version of 18 August 2026 — Publications Office of the European Union (EUR-Lex), 2026. regulation: only Provolone, 25 mg/kg as formaldehyde
- IARC Monographs Volume 100F — Chemical Agents and Related Occupations (2012) — International Agency for Research on Cancer, 2012. safety: formaldehyde is a Group 1 carcinogen
Checked against these sources on .
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