Health dyeing and fine dyeing have different dyeing effects, different quality and different prices. Usually fine dyeing has good effect and high price, which is more harmful to hair.
Attention should be paid to the harm of hair dyeing: secondary amine is easy to react with epoxy, aldehyde and acid gas, and can be used as dye fixative to stabilize the adhesion effect of dye. It can penetrate into skin and hair and stay for weeks, months or even years, and react with tobacco smoke or waste gas in the air to generate nitrosamines, which are a strong carcinogenic chemical. Once it enters the human body, it is difficult to excrete it, and it will accumulate in the body for a long time, which will cause poisoning.