Hexamethylene tetramine

E number E239INS 239CAS 100-97-0

Used as a preservative.

Hexamethylene tetramine is a preservative with one narrow permitted use in the European Union: provolone cheese. It works by releasing formaldehyde slowly.

Where it is and isn’t permitted

Status of Hexamethylene tetramine by jurisdiction. Every jurisdiction this site covers is listed, including those where the substance does not appear.
JurisdictionStatusScope and limitsCitation
United StatesFood and Drug AdministrationNot listedDoes not appear on this jurisdiction’s permitted list. That is not the same as being prohibited.
Codex AlimentariusCodex Alimentarius Commission / JECFAPermitted, with conditions

1 food category

highest permitted level 25 mg/kg

CXS 192-1995 Table One, INS 239, food category 01.6.2.1retrieved 2026-09-07

What it is made from

Made by reacting formaldehyde with ammonia. Its use is restricted to a single named cheese, which is unusual even among the narrow listings in this standard.

  • Vegan
  • Vegetarian
CAS registry number
100-97-0
InChIKey
VKYKSIONXSXAKP-UHFFFAOYSA-N
PubChem
CID 4101

Every name it appears under

64 recorded names. A label may use any of them.

E number

  • E239

INS number

  • 239

CAS registry number

  • 100-97-0

Other names

  • 1,3,5,7-Tetraazaadamantane
  • 1,3,5,7-Tetraazatricyclo[3.3.1.1(3,7)]decane
  • 1,3,5,7-Tetraazatricyclo[3.3.1.13,7]decane
  • Aceto HMT
  • Aminoformaldehyde
  • Ammoform
  • Ammonioformaldehyde
  • Antihydral
  • Cystamin
  • Cystogen
  • Duirexol
  • E 239
  • Ekagom H
  • Esametilentetramina
  • Formamine
  • Formin
  • Formin (heterocycle)
  • Formine
  • Herax UTS
  • Heterin
  • Hexa (vulcanization accelerator)
  • Hexa-Flo-Pulver
  • Hexaform
  • Hexamethylenamine
  • HEXAMETHYLENE TETRAMINE
  • Hexamethyleneamine
  • Hexamethylenetetraamine
  • Hexamethylenetetramine
  • Hexamethylenetetraminum
  • Hexamethylentetramin
  • Hexamethylentetraminum
  • Hexamine
  • Hexamine (heterocycle)
  • Hexaminum
  • Hexilmethylenamine
  • HMTA
  • INS NO.239
  • INS-239
  • J50OIX95QV
  • Metenamina
  • Methamin
  • Methenamin
  • Methenamine
  • Methenamine, Silver
  • methenaminum
  • Nocceler H
  • Preparation AF
  • Resotropin
  • S 4 (heterocycle)
  • Sanceler H
  • Silver, Hexamine
  • Uramin
  • Uratrine
  • Urisol
  • Uritone
  • Urodeine
  • Urotropin
  • Urotropine
  • Vulkacit H 30
  • Xametrin

Systematic names

  • 1,3,5,7-tetraazatricyclo[3.3.1.1]-decane

Hazard reference values

No reference value for this substance in the sources we hold.

Evidence and how bodies read it

Studies, and the differing conclusions regulators drew from them, are curated by hand rather than machine-read, and none has been written for this substance yet.

Sources for this page

  • gsfa retrieved 2026-09-07

Full licence terms and publisher details on Sources. How this page is built and updated: Method.

Machine-readable:/api/v1/additives/hexamethylene-tetramine.json