Home / Additive Table / Hexamethylene tetramine (E239)

Hexamethylene tetramine (E239)

Table v1.3 (data as of 14 Aug 2026), page updated 26 Sep 2026

Hexamethylene tetramine is the preservative the food industry lists as E239. In our table it is moderate risk: it takes 15 points off the additive subscore, a third of a product's score (about 5 of the 100).

In short
  • The key finding, from EFSA: 'Due to the limitations in the database the Panel could not identify a critical study and therefore to derive an ADI.' Child exposure to formaldehyde from HMT could reach 87 µg/kg bw/day under a conservative assumption; the Panel nonetheless concluded the Provolone-only use at 25 mg/kg is not of safety concern, and that any extension of use would need new toxicity data (10.2903/j.efsa.2014.3696 (EFSA Journal 2014;12(6):3696))
  • No child flag. The class, and the points it costs, are the same for a child of any age.
  • Where you meet it. None of the 10,000 packaged foods scanned most on Open Food Facts list it. Nine in ten of those foods are sold in Europe (counted 26 Sep 2026).
  • 3 citations from EFSA, IARC and the FDA, each one below.

What Hexamethylene tetramine does to a score

A packaged food's additive subscore starts at 100 and loses points for each additive on the label; that subscore is a third of the final score. Hexamethylene tetramine takes 15 points off the additive subscore, a third of a product's score (about 5 of the 100). Scan the pack in Sito and the score you get is the one for your own child's age, with this additive named in the reasons. How we score has the whole method.

See what is in your own cupboard

Scan a packaged food and Sito names the additives in it, then scores the product out of 100 for your child's age.

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Sito app: a cereal scored 30 out of 100 for a child's age Sito app: logging a child's meal from a photo

What the sources found

Every classification in our table comes from the citations below, and nothing else. Each finding is our one-line summary of what the source concluded, with the source and reference beside it.

  • EFSA 10.2903/j.efsa.2014.3696 (EFSA Journal 2014;12(6):3696)
    'Due to the limitations in the database the Panel could not identify a critical study and therefore to derive an ADI.' Child exposure to formaldehyde from HMT could reach 87 µg/kg bw/day under a conservative assumption; the Panel nonetheless concluded the Provolone-only use at 25 mg/kg is not of safety concern, and that any extension of use would need new toxicity data.
  • IARC classification list — Formaldehyde, CAS 50-00-0, Group 1
    The breakdown product is Group 1, but on inhalation evidence; there is no IARC classification of hexamethylene tetramine itself and no dietary-route Group 1 finding.
  • FDA eCFR search of 21 CFR — no listing for hexamethylenetetramine/hexamethylene tetramine as a food additive
    Not permitted in US food.

Why this class

IARC Group 2B; or an EFSA re-evaluation that flagged genotoxicity data gaps, found safety could not be assessed on the available data, or cut the ADI citing child exposure; or an EU harmonised classification of the substance as a reproductive or developmental hazard; or an EU withdrawal of one authorised food use while others remain; or an OEHHA/Proposition 65 listing; or membership of the Southampton-six colourants.

Our confidence in this row's classification is medium. Medium or low does not mean the evidence is weak; it means something about the row is still being pinned down, usually a regulatory status confirmed from one source rather than two.

Questions parents ask

Is Hexamethylene tetramine (E239) safe for kids?

Moderate risk. In Sito it takes 15 points off the additive subscore, a third of a product's score (about 5 of the 100). The finding we rely on: 'Due to the limitations in the database the Panel could not identify a critical study and therefore to derive an ADI.' Child exposure to formaldehyde from HMT could reach 87 µg/kg bw/day under a conservative assumption; the Panel nonetheless concluded the Provolone-only use at 25 mg/kg is not of safety concern, and that any extension of use would need new toxicity data (EFSA, 10.2903/j.efsa.2014.3696 (EFSA Journal 2014;12(6):3696)).

What is E239?

E239 is the E number for Hexamethylene tetramine, a preservative. Open Food Facts tags it en:e239.

Next to it on the label

The E numbers either side of E239 in our table, then the closest preservatives by number.

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