4,6-BIS-(2-HYDROXYETHOXY)-M-PHENYLENEDIAMINE HCL

About 4,6-BIS-(2-HYDROXYETHOXY)-M-PHENYLENEDIAMINE HCL

A permanent-hair-dye coupler in the phenylenediamine family. Effective for colour formation but a known sensitiser — EU-restricted, patch test required.

Detailed Analysis

4,6-bis-(2-Hydroxyethoxy)-m-phenylenediamine HCl (CAS 94082-85-6) is an aromatic diamine used as a coupler in oxidative (permanent) hair dyes. It reacts with primary intermediates such as p-phenylenediamine (PPD) and hydrogen peroxide to generate coloured indo-dye molecules in the hair shaft. The SCCS has evaluated several m-phenylenediamine derivatives and classed them as moderate to strong sensitisers; EU Regulation 1223/2009 Annex III sets strict concentration limits and mandatory warning labels for this chemical family. It is never used in leave-on cosmetics — only in short-contact oxidative dye systems, and manufacturers require patch testing.

Skin Benefits

• ✓ Acts as an oxidative hair-dye coupler
• ✓ Enables a wide colour spectrum in permanent dye systems
• ✓ Used only in small intermediate concentrations

Known Concerns

• ⚠ Aromatic amine hair-dye intermediate — known contact sensitiser class
• ⚠ EU regulates PPD-family intermediates in Annex III with use limits
• ⚠ Requires patch testing before application
• ⚠ Not suitable for leave-on or skin contact beyond dyeing session

References