2,7-NAPHTHALENEDIOL

2,7-Naphthalenediol is naphthalene-2,7-diol (CI 76645), an aromatic compound with two hydroxyl groups on a naphthalene ring. In oxidative hair colours it acts as a coupler that forms colour molecules together with dye precursors and an oxidising agent. CosIng lists it as a hair-dyeing ingredient. In the EU it is covered by an entry in Annex III (substances subject to restrictions), with mandatory label warnings.

Found in permanent (oxidative) hair colours and other hair colour products.

The INCI list shows which ingredients are present, not how much of each. Above 1%, ingredients are listed in descending order of weight; below 1% the order is free.

See the EU regulation section for the applicable limits, conditions and label warnings, which differ between oxidative and non-oxidative hair dye products. Its position on the list does not show the final shade, which depends on the combination of dyes in the product.