Methyldibromo glutaronitrile (MDBGN) is a widely used preservative.
It is made by reacting bromine with 2-methyleneglutaronitrile below 30 °C. An allergy to the chemical can be discovered by performing a patch test.
In the mid-1980s, a maximum concentration of 0.1% in stay-on and rinse-off cosmetics was allowed.[1] It was discovered soon afterwards that it caused allergic contact dermatitis to people with eczema.
It has been in use since the 1990s as a preservative in skin care products such as lotions, wet wipes, shampoo, and liquid soaps. Industrial applications include its use in preserving oils, glues, and medical gels.[2]
In 2005, the EU banned its use in stay-on products,[3] and in 2007 banned it in rinse-off products.
In 2005–06, methyldibromoglutaronitrile/ phenoxyethanol was the ninth-most-prevalent allergen in patch tests (5.8%).[4]