May 30, 2024

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Will phenylenediamine in hair dye cause cancer?

Will phenylenediamine in hair dye cause cancer?


Will phenylenediamine in hair dye cause cancer? The reason why hair dye is rumored to be carcinogenic is because it contains an ingredient called phenylenediamine!

Will phenylenediamine in hair dye cause cancer?
For people who often dye their hair, they should have heard the statement that “hair dyes cause cancer”, and even when the Internet was underdeveloped decades ago, there were rumors that hair dyes caused cancer!

The reason why hair dyes are rumored to be carcinogenic is because it contains an ingredient called phenylenediamine!


Broadly speaking, any hair dye product that can change hair color can be called a hair dye. However, in daily life, most of the hair dyes we use are permanent hair dyes.

This is an oxidative hair dye product. The process of dyeing the hair is to first allow the small molecule aniline colorant pre-sport coupling agent to penetrate into the inside of the hair, and then under the action of the oxidant, oxidative polymerization reaction gradually occurs to produce macromolecular pigment , And seal it in the hair fiber!


However, phenylenediamine, a coloring agent, is an internationally recognized carcinogen. During the hair dyeing process, the hair dye can not only contact the skin, mucous membranes and other areas, but some hair dye products need to be heated repeatedly in order to maintain better color retention . In the process of heating, harmful substances may enter the blood vessels with the scalp, increasing the risk of cancer!

A related research paper published in the authoritative medical journal “BMJ” also confirmed the connection between hair dye and cancer!

Researchers conducted a follow-up survey of 117,200 women for 36 years. The results of the study confirmed that women who use hair dyes have no risk of cancers such as blood cancer, kidney cancer, and melanoma compared with women who have never dyed their hair. increase.

However, there is a kind of cancer that is indeed related to permanent hair dye. It is basal cell carcinoma of the skin. The more light-haired women, the higher the possibility of cancer later;


In addition, a research report published in the International Journal of Cancer has conducted surveys on 46,709 women in the United States. After 8 years of follow-up investigation, 2794 of these women have developed breast cancer, and 55% of them are participating In the experiment, they all clearly indicated that they have the experience of using permanent hair dye. The results show that permanent hair dye will increase the risk of breast cancer by 45%!

Various research investigations have shown that permanent hair dye is indeed related to cancer, but this does not mean that you cannot dye your hair!


You know, these experimental conclusions do not explain the problem, and they are not aimed at the Chinese. Moreover, there are too many uncertain factors in the emergence of cancer. Research for several years and decades has shown that women’s cancerous changes may be affected by other factors, such as exposure to carcinogens, genes, age, Chronic diseases, etc., so this does not fully explain the problem;

Moreover, some countries has clear regulations on cosmetics that the concentration of phenylenediamines in hair dye products cannot exceed 6%. In other words, buying qualified hair dyes will not increase your own risk of cancer.

You know, any talk about toxicity directly beyond the dose is actually hooliganism. However, frequent hair dyeing does increase the chance of contact with carcinogens and damage the hair quality and scalp. Therefore, it is scientifically recommended that you should not dye your hair more than twice a year.



(source:internet, reference only)

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