Often dye hair, easy to cause cancer? Reminder: 3 points can be done before dyeing, which can reduce the damage of hair dyeing

Hair dyes are extracted from petroleum and have a pungent taste. Hair dyes contain some harmful substances, such as formaldehyde, phenols and benzene, which are classified as a class of carcinogens. If they are exposed for a long time, they will accumulate slowly in the body, thus increasing the risk of cancer. In addition, hair dyes also contain a 2-4-aminoanisole component, which also accumulates in the body, causing cell proliferation. If you use hair dye for more than 10 years, 1% of the skin absorption will cause cancer. In addition, there are secondary amines in hair dyes, which react with aldehydes and acid gases to stabilize the adhesion of dyes, but they will slowly penetrate into the skin and hair, staying for months or years. At the same time, it will react with the exhaust gas in the air to produce ammonium nitrite, which is a high-risk factor for cancer. < / P > < p > in general, allergic symptoms such as redness, itching and dandruff will appear in a few hours or days after hair dyeing, and edema or long blisters on the scalp and face of severely allergic people. If there is no improvement after 3-4 days, the regular hospital should be selected to use antihistamines reasonably. Before each hair dyeing, it is necessary to do experiments on weak skin such as wrists or ears, and apply a small amount of it. As long as there are no allergic symptoms after 2-3 days, hair dyeing can be carried out. < / P > < p > some components of hair dye can make hair scales open on the surface of hair, which can make the dye coloring. If you use hair dye frequently, it will make the hair thin and fragile, and the hair is easy to be injured and become dim and no luster. Hair dyeing effects can be divided into temporary, semi permanent and permanent. The first is to apply the dye directly to the outermost layer of the fur without any damage. The second kind can resist about 12 times of shampoo, and the damage to the hair is slightly smaller. But the last hair dye will oxidize with the hair, making the dye into the hair fiber, prolonging the retention time, and causing unexpected damage to the scalp. Therefore, try to choose semi permanent hair dye. < / P > < p > hair dyes produced by regular manufacturers contain less heavy metals, and have no effect on the body. But bad hair dye contains a lot of heavy metals, which will accumulate in the body and cause heavy metal poisoning. < / P > < p > hair dyes contain p-phenylenediamine, which is a dye intermediate and can promote hair coloring. However, in the process of hair dyeing and heating, such substances will enter the capillaries through the scalp, not only carcinogenic, but also sensitized. < / P > < p > since we have known the harm of hair dyeing, we should control the number of hair dyeing. The number of times of hair dyeing should not exceed two times in a year. We should not dye our hair when there is a wound or skin disease. < / P > < p > hair dyes produced by regular manufacturers must be selected instead of seeking temporary cheap. Skin test should be done before each hair dyeing to ensure that there is no allergic phenomenon in two days before hair dyeing. < / P > < p > wash your hair at least three to four times after dyeing, which can reduce hair dye residue. Hair repair should be done after hair dyeing, which can reduce the damage to hair quality. < / P > < p > when dyeing hair, the hair dyeing part should be at least 2 ~ 3cm away from the scalp. After hair dyeing, the hair should be cleaned thoroughly, and the scalp should not be scratched to avoid infection. Cai Shaofen stopped pregnancy for the first time. The 4 indexes on the B-ultrasound sheet in the early pregnancy were used to see whether the fetal development was good or not