Cosmetic ingredient

TOLUENE-2,5-DIAMINE

TOLUENE-2,5-DIAMINE, also called 2,5-diaminotoluene, is an aromatic amine used in oxidative hair-colouring products. Its structure has an aromatic ring, a methyl group and two amino groups. It may appear on a label under the INCI name or under the closely related chemical name.

INCITO1 products
CAS number
95-70-5
EC number
202-442-1
Chemical name
2-Methyl-p-phenylenediamine (CI 76042)

TOLUENE-2,5-DIAMINE: what it is

TOLUENE-2,5-DIAMINE, also called 2,5-diaminotoluene, is an aromatic amine used in oxidative hair-colouring products. Its structure has an aromatic ring, a methyl group and two amino groups. It may appear on a label under the INCI name or under the closely related chemical name.

It is not another name for p-phenylenediamine, even though both are aromatic amines used in hair dyes. Their groups occupy different positions in the molecule. Hair-colour products may use the free compound or a related salt, such as the sulfate, as part of the colourant system.

TOLUENE-2,5-DIAMINE: what it does in cosmetics

TOLUENE-2,5-DIAMINE is used to develop colour in oxidative hair dyes. When the product is used, it takes part in colour-forming reactions with the developer and other ingredients; the practical result is a change in hair shade, rather than a conditioning or treatment effect.

The finished shade does not come from this ingredient alone. It depends on the other colour precursors, couplers, oxidant and application time in the dye. Clinical patch-test research identifies it among allergens examined in reactions linked to hair colour products, but studies of referred patients do not show how often reactions occur among all users.

TOLUENE-2,5-DIAMINE: conditions and care

Hair dyes containing TOLUENE-2,5-DIAMINE can trigger an allergic reaction in people who are sensitised. A previous reaction to hair dye warrants professional advice before using another product; follow the product instructions and warnings closely.

Use limits

Restrictions and conditions of use

Cosmetic restriction
III/9a
Catalogue presence

Products containing this ingredient

See which products include it and the name used in each composition.