Hair dye must be all. Does it contain m-phenylenediamine?

There are two kinds of phenylenediamines:

Phenylenediamine is an industrial dye, which is mainly used for some fur processing and dyeing. Because this kind of dye is cheap and fast, some unscrupulous merchants cheat consumers with its fast dyeing effect in order to make huge profits and add it to hair dye.

P-phenylenediamine, which is allowed to be used internationally, is also a toxic dye, but it is safe as long as the dosage is well controlled. Moreover, there are also hair dyes that do not contain p-phenylenediamine on the market, and the packaging will indicate that consumers can also pay attention to the ingredients of hair dyes during the purchase process.

How to detect whether the hair dye is safe;

Usually, after using the hair dye containing m-phenylenediamine, consumers will have allergic reactions within two hours, and one day later, they will have severe allergic symptoms on their faces and herpes on their scalp. Therefore, consumers are advised to do an after-ear allergy test before using hair dye products, and they can only use them after 48 hours without allergic reactions such as redness, swelling and tingling.

Moreover, when many consumers use hair dye products, there is a misunderstanding: using the same brand of hair dye, the allergy test only needs to be done for the first time, not for the second time. This idea is wrong. Because of the influence of seasons and weather, people's skin will have different allergic reactions, so it is safe to do allergic tests before dyeing hair every time.