There are also oxidation dye precursors, coupling agents, oxidants and substrates, most of which are synthetic small molecular compounds. Among them, dye precursors mainly include p-phenylenediamine, p-aminophenol, methyl phenylenediamine and their isomers and derivatives.
Coupling agents mainly include resorcinol, chlorinated resorcinol, methyl resorcinol and their homologues and derivatives; The oxidant is usually hydrogen peroxide, sodium perborate, urea hydrogen peroxide, etc. The matrix usually includes surfactants, solvents, etc.
Pay attention to dyeing hair:
Do an allergy test before dyeing hair, apply a small amount of hair dye behind the ear or inside the elbow, and stick it with breathable tape for 24 ~ 48 hours. If the skin is red, swollen and burning during the test, you are allergic to this hair dye and should avoid using it. If there is no response, it means safety. Phenylenediamine is more allergic. Once the hair dye is allergic to aniline, it will have symptoms such as headache and scalp swelling.
It is best for young people to dye their hair by highlighting, and try not to dye their hair near the hair roots, so as to avoid the contact between hair dye and scalp and reduce the risk of harmful substances infiltrating into the head.
Women during pregnancy and lactation should not dye their hair. People with head and neck trauma, skin diseases or skin test abnormalities, patients with allergic diseases such as asthma, boils, skin ulcers, hematological diseases and tumors should stay away from hair dyeing.