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E239 / Preservatives

Hexamethylenetetramine

Selected sources checked · Scope & sources

Safety in brief

Better avoided

Recorded EatMatrix rating, not a new clinical review. The amount, your sensitivities and country rules still matter.

Watch for
No allergen or sensitivity is recorded for this ingredient here. Check the whole product label; this is not an allergen-free guarantee.
Our advice
Read the whole food label and consider how often you eat the product. A name or E number does not tell you the amount, and an ingredient rating cannot assess the entire food.
What it is

Hexamethylenetetramine (also called methenamine or hexamine) is a preservative with limited, specific food use, most notably in some traditional provolone-type cheeses, where it slowly releases small amounts of formaldehyde to inhibit spoilage bacteria and molds. It has broader industrial uses in resins and adhesives, and is used in medicine as a urinary-tract antiseptic (at much higher, therapeutic doses). Its food use is tightly restricted by regulators because of the formaldehyde it releases, and it is banned or heavily limited in many jurisdictions outside its traditional cheese applications.

Also appears on labels as: E239, E 239, E-239, INS 239, Hexamethylenetetramine, Hexamine, Methenamine, Urotropine, Hexamethylene tetramine, Methenamin, Methenaminum, Formin.

Dietary information

Vegan
Yes
Halal
Yes
Gluten-free
Yes
Allergens
None recorded

Recorded ingredient information. Check the product label or certification: sources, other ingredients and cross-contact can vary.

Research & body effects

Health notes from our ingredient record

  • Releases formaldehyde, a substance with its own safety concerns (see E240); food use is restricted to specific traditional products and closely regulated maximum levels.
  • Prolonged or high-level exposure (mainly relevant to industrial, not food, contexts) may cause skin or respiratory irritation.

Other references from our ingredient record

These links come from the original ingredient record. They are separate from the source reviews above and have not all been checked for the exact ingredient, amount consumed or claim. Dates are shown newest first.

  1. Scientific Opinion on the re‐evaluation of hexamethylene tetramine (E 239) as a food additive — EFSA Panel on Food Additives, EFSA Journal (2014). Official EFSA scientific opinion (bibliographic reference, imported 2026-10-13). It covers the additive as a group assessment and is not an individual human study; read the opinion for its findings.
  2. Hexamethylene Tetramine (E239) – Preservative — EFSA Panel on Food Additives, EFSA Journal (2013). ADI withdrawn; decomposes to formaldehyde in acidic conditions; restricted to Provolone cheese; potential carcinogen at high exposure.[avoid]
Country rules

Country checks for E239

Permission depends on the market, type of food, amount and conditions. A scientific opinion or an E-number alone does not establish a legal use. These checks are separate from the stored EatMatrix rating.

Compare all eight markets and their sources
MarketWhat is checked
European Union

Regulation (EC) 1333/2008, Annex II Part B, version , contains the exact code E239: Hexamethylene tetramine.

Listing alone does not allow every food use. Part E food categories, limits, specifications and applicable later acts still need a product-specific check. Source read: .

Great Britain

The FSA register record for E239 (Hexamethylene tetramine) lists “Authorised” in England, Scotland and Wales.

Register updated: 01 April 2025; record checked: . Food-specific conditions and specifications still need a separate legal check.

United States

Complete current-use review pending. Any scoped provision in the label guide above applies only to the stated use. FDA explains the applicable food-additive and GRAS framework.

Northern Ireland

Review pending. Check the applicable EU rules and territory arrangements; the GB register alone does not establish this status. FSA guidance is a starting source, not a verified permission for this entry.

Canada

No exact named entry located in the reviewed additive lists

No exact named food-additive entry was located in the 15 current lists for Hexamethylenetetramine; Hexamine. Other preservatives cannot establish permission for hexamine.

EatMatrix reading: Do not claim a permitted additive use from this review. Exact preparation, intended use and any applicable separate legal provision need confirmation; this table result is not a toxicology verdict or proof of a universal ban.

Name and category review: . This describes the legal source check, not a finding that the ingredient is safe, unsafe or untested.

Sources and names checked

Names checked: Hexamethylenetetramine; Hexamine.

All 15 Health Canada permitted-additive lists were checked by exact name, with the reviewed alternatives above. E-numbers alone are not Canadian ingredient names.

The Justice Canada consolidation read was current to 21 September 2026. A complete product decision also requires its composition, specifications, intended food and use, quantities, applicable separate provisions and any later changes.

Australia

Review pending. Food Standards Code permissions and conditions need an additive-specific check. FSANZ food-additive rules is a starting source, not a verified permission for this entry.

New Zealand

Review pending. Food Standards Code permissions and conditions need an additive-specific check. FSANZ food-additive rules is a starting source, not a verified permission for this entry.

Japan

Review pending. The relevant list, identity and use standards need an additive-specific check. CAA food-additive lists is a starting source, not a verified permission for this entry.

Sources & review status

Check what each source covers: an authority’s conclusion, a research finding and a country’s legal permission answer different questions.

What this guide covers

Official assessment sources
Commission-listed EFSA references for E239. Bibliographic identity checked; latest findings and current use rules need separate review.
Original ingredient record
2 research links; newest recorded date: . Sources added separately to this guide are not included in this count.

This guide brings together our ingredient record and the dated sources shown here. Missing information describes a gap in this guide; it does not mean an ingredient is untested, safe or harmful. This is not a complete review of every study, preparation or current country rule. The amount in a product and how it is used still matter.

How to read the ratings, research and country checks
Agency labels recorded by EatMatrix

These are imported database classifications, not verified current statements from each authority. Use the dated official sources below for their actual scope and conclusions.

AuthorityDatabase label
FDABetter avoided
WHOBetter avoided
EFSABetter avoided
FSANZBetter avoided
JapanBetter avoided
UK FSABetter avoided
Health CanadaBetter avoided

Official assessment sources for E239

The European Commission’s re-evaluation table lists official EFSA documents for this additive. Their identifiers and subjects were checked against publisher bibliographic records. A missing research link in the EatMatrix database does not mean the additive has never been assessed.

Name in the Commission table: Hexamethylene tetramine.

These are assessment references, including historical or group assessments. They do not establish the latest scientific conclusion, a human health benefit or risk, or current permission to use the additive in a particular food. Later assessments, corrections and food-use conditions need separate review. The recorded EatMatrix rating above is unchanged.

European Commission re-evaluation table, status as of . EatMatrix checked this bibliography on .

Database updated: . What does an E number mean on a food label?

Common questions

Frequently asked questions

What is EatMatrix's recorded rating for E239?

The recorded EatMatrix rating for E239 (Hexamethylenetetramine) is “Better avoided”. It is calculated from labels stored in our ingredient database. These labels are not verified current regulator decisions or country permissions. A database update date is not a scientific review date.

Is E239 vegan, halal or gluten-free?

According to our ingredient data for Hexamethylenetetramine — vegan: yes, vegetarian: yes, halal: yes, kosher: yes, gluten-free: yes, dairy-free: yes. Manufacturing sources can vary between products; check the label if it matters to you.

What is E239 and why is it used?

Hexamethylenetetramine (also called methenamine or hexamine) is a preservative with limited, specific food use, most notably in some traditional provolone-type cheeses, where it slowly releases small amounts of formaldehyde to inhibit spoilage bacteria and molds. It has broader industrial uses in resins and adhesives, and is used in medicine as a urinary-tract antiseptic (at much higher, therapeutic doses). Its food use is tightly restricted by regulators because of the formaldehyde it releases, and it is banned or heavily limited in many jurisdictions outside its traditional cheese applications.

Does E239 contain allergens?

No known allergens are recorded for Hexamethylenetetramine.

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This page shows information and classifications recorded in our ingredient database. Current scientific and market-specific verification remains pending as described above. It is general information, not medical advice.