Hair coloring and health
The use of hair dyes has been used for thousands of years, and legend has it that ancient Egypt, ancient Greece and ancient China had the habit of dyeing hair, using extracts of plants such as henna, which women used to cover gray hair.
At present, the hair dyeing water currently produced in China is mainly white dyeing black (beauty supplies), and there are also a small amount of black dyeing yellow (art supplies) for actors to wear makeup. The dyes of hair dyes can be divided into three types: plant-based, mineral and synthetic hair dyes. Mineral hair dyes are doped with oxides of lead, iron, copper, bismuth, nickel, cobalt and other metals.
Among them, lead, copper, nickel, cobalt and other metals are toxic and have been banned in many countries. Plant-based hair dyes use henna leaves, chamomile flowers, walnut shells, betel nuts, etc. as raw materials, and the more commonly used are henna leaves. Henna leaves are not toxic and irritating to the whole body or locally.
Synthetic hair dyes contain a variety of chemical components, the main components of which are p-phenylenediamine, sodium edta, p-aminophenol, resorcinol, o-aminophenol, etc., they have different degrees of toxicity, can cause local dermatitis. Animal experiments have carcinogenic, teratogenic, mutagenic and other effects.
For health and safety, it is best to choose plant-based hair dyes, and it is best not to use hair dyes during pregnancy. Hair dye potion is also not suitable for people with allergic reactions or skin diseases.
