What is methyldibromo glutaronitrile and where is it found?

Methyldibromo glutaronitrile (MDBGN) is a bromine-containing preservative that has been used in cosmetic and toiletry preparations as well as in some industrial products. A maximum concentration of 0.1% MDBGN in stay-on and rinse-off cosmetics was approved for use in the mid-1980s and animal tests showed it to be a weak sensitiser compared to other preservatives used at the time. By the 1990’s it became a commonly used preservative, particularly in cosmetic and self-hygiene products.

However, methyldibromo glutaronitrile was soon discovered to cause allergic contact dermatitis reactions in eczema patients. Rates of sensitisation to MDBGN increased from 0.7% in 1991 to 3.5% in 2000 in patch test studies from 16 European centres. In the United States, sensitivity rates were up to 11.7%. In 2005, the European Union banned the use of MDBGN in stay-on products, and then later in 2007 also in rinse-off products. Recent data from Europe observed a significant decrease in positive patch test reactions since the ban of MDBGN.

What are the reactions to methyldibromo glutaronitrile allergy?

In methyldibromo glutaronitrile allergic individuals, contact with MDBGN produces classic allergic contact dermatitis.

The dermatitis is usually confined to the area of contact and may cause itching, burning, scaling, hives (urticaria), and blistering of the skin.

Am I allergic to methyldibromo glutaronitrile?

Methyldibromo glutaronitrile allergy is diagnosed by performing special allergy tests, i.e. patch testing. Concentrations of 0.5% methyldibromo glutaronitrile in petrolatum can be used for patch testing. It is part of the European Standard Series in the baseline series of patch test allergens.

Treatment of methyldibromo glutaronitrile allergy

Confirmation of methyldibromo glutaronitrile allergy requires the removal of the causative agent and then management as for any acute dermatitis/eczema; this may include treatment with topical corticosteroids and emollients.

What should I do to avoid methyldibromo glutaronitrile allergy?

Patients with methyldibromo glutaronitrile allergy should avoid direct skin contact with products containing this preservative. If you have a sensitivity be sure to read product labels in all personal care products before you use them. Be aware of alternative names for MDBGN. If unsure, ask your pharmacist for advice or a suitable alternative.

Alert your doctor, pharmacist, dentist, veterinarian, beautician, and hairdresser to the fact that you have an allergy to MDBGN.

If MDBGN is used in your workplace, use heavy-duty gloves and/or protective clothing to prevent contact.

Your dermatologist may have further specific advice, particularly if you are highly sensitive to MDBGN.

Alternative names for methyldibromo glutaronitrile

• 2-Bromo-2-(bromomethyl)pentanedinitrile
• 1,2-dibromo-2,4-dicyanobutane
• 1-Bromo-1-(bromomethyl)-1,3-propanedicarbonitrile
• 2-Bromo-2-(bromomethyl) glutaronitrile
• Dibromodicyanobutane
• Bromothalonil
• Euxyl K400
• Tektamer 38
• Merquat 2200
• Metacide 38

Further information

Formula: C₆H₆Br₂N

CAS number: 35691-65-7

Cross-reactions: none of major concern

Appearance: white to yellow crystals

Sensitiser: methyldibromo glutaronitrile

Patch test: 0.5% methyldibromo glutaronitrile in petrolatum