Guthrie blackening agent, blackening at normal temperature, completely blackening without electricity, the same as alkaline high temperature.

Hair dye is a cosmetic for dyeing hair. Divided into temporary, semi-permanent and permanent hair dyes. Hair dyes generally contain carcinogen p-phenylenediamine. Experts say that p-phenylenediamine is a colorant that must be used in hair dyes and is an internationally recognized carcinogen.