Other names for the additive (synonyms)
General Information
Hexamethylenetetramine or urotropine is a food additive E239 used in products as a preservative.
The action of additive E239 is based on its ability to slowly decompose in an acidic environment, forming formaldehyde, which exhibits strong antimicrobial effects: it denatures microbial proteins, inactivates enzymes, and disrupts cell membrane structures. As a result, bacterial and fungal growth is suppressed, providing a preservative effect.
This substance does not occur naturally in pure form – it is obtained synthetically. Additive E239 was first synthesized in 1859 during studies on the reactions of formaldehyde with ammonia. The initial purpose of the synthesis was not to create a food additive. Only by the late 19th century were its practical properties discovered — its ability to decompose in acidic environments to form formaldehyde, which led to its use as an antiseptic in medicine and a preservative in certain food and technical applications.
As additive E239, hexamethylenetetramine has been used in the food industry for over half a century.
The chemical formula of additive E239 is C6H12N4. It is a white crystalline substance with a slightly sweet taste. Urotropine is highly soluble in water and, as mentioned above, decomposes into formaldehyde and ammonia under acidic conditions.
For the food industry, additive E239 is obtained by reacting formaldehyde with ammonia under controlled conditions. This allows the creation of a stable additive suitable for food applications.
Effects on the Body
Benefit of Additive E239
Food additive E239 is not a natural substance for the human body and does not provide direct nutritional benefits. Its main role is to prevent bacterial growth and extend the shelf life of products.
Risks of Additive E239
In the stomach, additive E239 decomposes under acidic conditions into formaldehyde and ammonia. The body can partially metabolize these substances: formaldehyde is quickly converted to formic acid and excreted in urine, while excess ammonia is converted into urea.
Hexamethylenetetramine (additive E239) has been evaluated by international expert organizations, including JECFA, which in 1974 established an ADI of 0.15 mg/kg body weight per day.
A later EFSA assessment confirmed that under the current limited use of additive E239 (only in Provolone cheese) at 25 mg/kg residual level (as formaldehyde), there is no safety concern, although any expansion of use or increase in the permissible level would require a new detailed evaluation.
Exceeding the acceptable daily intake (ADI) for additive E239, set at 0.15 mg/kg body weight, may cause gastrointestinal irritation and increased liver load.
At high doses or with prolonged use, urotropine may cause nausea, abdominal pain, vomiting, diarrhea, dyspepsia, dysuria, hematuria.
Additive E239 also may trigger allergic reactions: skin rashes, itching, urticaria, contact dermatitis, and other similar symptoms in sensitive individuals.
Leading expert organizations (EFSA, JECFA, and FDA) note that when used only in cheese within regulatory limits, the risk of side effects is minimal.
Uses
In the food industry, additive E239 is used as a preservative in hard and soft cheeses (such as Provolone) and sometimes in meat products.
Previously, additive E239 was actively used in the production of red caviar. However, it is now being replaced by safer preservatives.
Hexamethylenetetramine is used not only in the food industry but also in several other fields:
- Medicine and Pharmaceuticals - as a drug (methenamine) for the prevention and treatment of urinary tract infections, where its action is due to the release of formaldehyde in an acidic environment.
- Chemical Industry - as a raw material for the synthesis of phenol-formaldehyde resins, plasticizers, explosives, and special polymers.
- Fuel and Technical Applications - component of solid dry fuel (“solid alcohol” tablets) for camping and emergency stoves.
- Rubber and Textile Industry - as a vulcanization accelerator and stabilizer in rubber and latex production.
- Analytical and Laboratory Practice - reagent in chemical and microbiological studies.
Legal Status
In the EU, food additive E239 is allowed only in Provolone cheese according to Regulation (EEU) No 1333/2008 on food additives, with a maximum residual amount of 25 mg/kg as formaldehyde.
In Ukraine and most European countries, similar restrictions apply.
In the USA, the FDA permits additive E239 for food use but restricts product categories.
In Canada and Japan, E239 use is also regulated and allowed only in specific cheese products. The ADI is set at 0.15 mg/kg body weight.