HYDROXYPROPYL BIS(N-HYDROXYETHYL-P-PHENYLENEDIAMINE) HCL [HYDROXYPROPYL BIS(N-HYDROXYETHYL-P-PHENYLENEDIAMINE) HCL]
Hydoxypropyl bis(N-hydroxyethyl-P-phenylenediamine HCl is a colour precursor found in permanent oxidative dyes (oxidation base in the diamine family). In combination with oxidation couplers, it adds background colour (natural and ash shades) and covers grey hair. It is a high tenacity dye, patented by L'Oréal.