Toxicity in hair dyes is mainly due to paraphenylenediamine (PPD), a chemical substance which is widely used as an oxidisable hair dye. It is a permanent dye that gives a natural look.
The toxic effect of PPD depends on its oxidation and forms a base that is allergenic,(cause allergies) mutagenic (causes changes) and is highly toxic. Reactions in hypersensitive users when PPD comes in contact with the skin include dermatitis to the upper eyelids or ears and swelling of the scalp and face.
Allergic contact dermatitis may become widespread in the body as well. Severe allergy to PPD could result in swelling patches on the skin surface, (ST/KH)
