Ingredient
METHENAMINE
Name / description
Methenamine; Hexamethylenetetramine, Hexamine, Urotropine, 1,3,5,7-Tetraazaadamantane; in food: E 239
Function(s) of this ingredient in cosmetic products
ANTIMICROBIAL
Helps control the growth of micro-organisms (eg bacteria and fungi)
PRESERVATIVE
Protects cosmetic products from microbial spoilage
Origin
synthetic
Occurrence in cosmetics
Preserved cosmetics
Occurrence in other products
Medicinal products and medical devices (more particularly dental and veterinary medicinal products), rubberware, wood colourants
Background information on use in cosmetics
Methenamine is a so-called formaldehyde releaser. Preservatives protect cosmetic products against microbial spoilage and hence make a major contribution to consumer health. Preservatives are particularly required in cosmetic formulations containing water, because microorganisms can colonise and reproduce in an aqueous (water-containing) environment. Cosmetics often contain more than one preservative substances and these preservative systems act simultaneously against different bacteria, yeasts or moulds. Each of these substances has been comprehensively tested and assessed for safety (individually and in combination). Manufacturers always use only the lowest possible effective concentration in a product so that an optimum shelf life and safe application are ensured. Formaldehyde releasers continuously release a low amount of formaldehyde in the finished cosmetic product and deploy their preservative effect in this way.
Information on safe use
In accordance with the EC Cosmetics Regulation (Regulation (EC) No. 1223/2009), which applies to the entire EU market, preservatives means substances which are exclusively or mainly intended to inhibit the development of microorganisms in the cosmetic product. Annex V of the Regulation defines the substances which may be used as preservatives in cosmetic products. In this so-called positive list of preservatives, maximum concentrations are defined for the use of these substances in cosmetic products as well as the permissible uses. Preservatives are examined in respect of their toxicological safety prior to their approval in Annex V and undergo extensive tests. Manufacturers must prove the health safety in extensive scientific studies.
Why are we talking about it?
These substances release formaldehyde which is classified as a carcinogen. Formaldehyde is also known to induce/elicit allergies (sensitisation). The facts: The use of Formaldehyde as such in cosmetic products has been banned. It is known to be a sensitiser (contact eczema) and is classified as a carcinogen. However, use of Formaldehyde-releasing preservatives is continued to be explicitly permitted. The latter are strictly regulated, like all preservatives, and the permitted maximum concentrations of releasers ensure that the content of free Formaldehyde in cosmetic products is limited to a very low level. This resulting free Formaldehyde level is considered safe by several expert committees (European, Danish, American) (1, 2, 3) especially as percutaneous penetration of Formaldehyde is insignificant. Key points to take away: In view of the severe restrictions imposed on the use of formaldehyde releasing preservatives in cosmetic products, the resulting concentrations of free formaldehyde in the final products are controlled to remain very low. These preservatives are therefore considered safe by the experts. As an additional legal restriction, all cosmetic products containing free Formaldehyde from formaldehyde releasers above a defined low threshold must be labelled "Releases formaldehyde". Thus, people who are allergic to Formaldehyde are advised to avoid exposure towards their allergen (1) by carefully reading the product labels. (1) Scientific Committee on Consumer Safety: Advice SCCS/1632/21 (2) Survey and health and environmental assessment of preservatives in cosmetic products - The Danish Environmental Protection Agency, 2015 Survey of chemical substances in consumer products No. 138, 2015: https://www2.mst.dk/Udgiv/publications/2015/05/978-87-93352-19-3.pdf (3) CIR - Amended Safety Assessment of Formaldehyde and Methylene Glycol as Used in Cosmetics - Ivan J et al. - International Journal of Toxicology 32(Suppl. 4):5-32, 2013
Further information
For the clarification of a suspicion of a contact allergy this substance can be routinely tested in the epicutaneous test at the dermatologist.
Belongs to the following substance groups
Regulating cosmetics
Cosmetics Ingredients are subject to regulation. Please note, different regulations may apply to cosmetic ingredients outside the EU.
Database
Cosmetics matter to people and play an important role in our everyday life. On average European consumers use over seven different cosmetics daily. You too? It’s only natural that you want to know more about the ingredients in those products.
In the digital world we live in, there’s a deluge of information on cosmetics. However, it can be difficult to know which sources are reliable. COSMILE Europe is a European cosmetic ingredient database that offers reliable, verified and scientifically supported information on almost 30,000 ingredients used in cosmetics.
This database will help you understand why certain ingredients are in your cosmetic products; which properties they have and much more. The database is currently available in fourteen languages with more to come.
