E239 is a food additive approved by the European Union (EU) and used as an antibacterial and antifungal synthetic preservative in food products, especially cheese.
The common name for E239 is hexamethylene tetramine. It may also be known as hexamine or methenamine.
E239 becomes metabolised by the liver to then be excreted. It can be used to treat urinary tract infections, due to the low (acidic) pH of the urine in which E239 is hydrolysed. The resulting chemical, formaldehyde, works as an antiseptic when outside the body (in vitro).
E239 has been suspected of causing stomach upsets with long term ingestion. Hexamine may also be carcinogenic and is currently banned in Australia. It is thought to irritate skin and worsen asthma, as well as provoking headaches and bronchitis.
Examples of food and drink products that sometimes include E239:
- marinated fish