A: Hair dyes contain bleaching chemicals such as hydrogen peroxide and some brands of mixtures. Paraphenydiamine (P-Phenylenediamine, PPD) and Paratollluene Dimine (P-Touenediamine, PTD) In which all the substances mentioned above It is a substance that can cause allergies, irritation and residues easily on the scalp. Noticed from the time the hair dye is finished Often there is a chemical smell on the scalp and the cloth to set up for another 1-2 days, which if you have used it regularly. It may cause the hair roots to become weak And hair fall off easily For those who dye their hair, it is necessary to keep the scalp healthy. Reducing the residue of chemicals is an important component too.