Toluene-2,5-Diamine Sulfate
Toluene-2,5-Diamine Sulfate is a common oxidative hair dye ingredient used in permanent and semi-permanent hair colours sold in the UK. It helps create natural-looking shades from brown to black by reacting with hydrogen peroxide and couplers during the colouring process. It is strictly regulated in the UK and EU, with usage limits and mandatory patch-testing instructions on every pack.
How it works in skincare
In cosmetics, Toluene-2,5-Diamine Sulfate functions as a primary intermediate in oxidative hair dyeing systems. When mixed with an alkaline developer containing hydrogen peroxide, it oxidises and couples with other dye precursors to form large colour molecules that remain trapped inside the hair shaft, delivering long-lasting colour. It is almost exclusively used in hair colourants rather than skincare, where it is valued for its ability to produce stable, natural-looking brown and dark tones with good coverage of grey hair.
Key benefits
- Delivers long-lasting permanent hair colour
- Provides excellent coverage of grey hair
- Creates natural-looking brown to black shades
- Works effectively within standard home and salon colour formulas
- Offers good colour stability and fade resistance
- Allows precise shade matching when combined with couplers
Best for
not used on skin, hair colouring products only
Where it comes from
Toluene-2,5-Diamine Sulfate is a synthetic aromatic amine produced through chemical synthesis from petrochemical sources. It does not occur naturally in plants, minerals or other raw botanical materials.
Products with Toluene-2,5-Diamine Sulfate
Not every product on UK Lips lists a full ingredient breakdown — so there may be many more formulas that contain Toluene-2,5-Diamine Sulfate than we can show here. These are the comparisons where we’ve confirmed it in the listed ingredients.