Nowadays, people have more and more demand for hair coloring, and young people are pursuing fashionable hair colors, such as cherry blossom pink, denim blue, and polar star green. Older people also yearn for a younger appearance, dyed black and white hair, and the years are not scary.
(Source: soogif)
Due to the popularity of self-service hair dyes, more and more people are starting to dye their hair at home. In addition to the convenience of use, the frequency of hair dyeing is also increasing. So how much do you know about the physical impact of hair dyeing on your body, who have dyed your hair all the year round?
In the cognition of many elders, there are a lot of heavy metals in hair dye products. In fact, hair dyes made of heavy metals have basically withdrawn from the stage of history because of the accumulation of toxins in the human body.
Currentlymost hair coloring products on the market are oxidative hair coloring products, the hair coloring agents commonly used in such hair coloring products are phenylenediamines, among which Phenylenediamine is one of the important dyeing raw materials in oxidative hair dyes because of its firm dyeing and long-lasting coloring.
But p-phenylenediamine is considered to be a Class III carcinogen, that is, a substance with “insufficient evidence of carcinogenicity”. Tea and coffee are also classified as Class III carcinogens.
It is worth noting that although the carcinogenic evidence of p-phenylenediamine is insufficient, it is susceptible to sensitization. Studies have also shown that due to the occupational nature of hairdressers, long-term exposure to phenylenediamine-based oxidative hair dyes will lead to an increased risk of cancer.
Here is “occupational exposure”, that is, due to occupational factors, daily exposure to hair dye products, most people dye their hair two or three times a year, the risk of cancer is far from reaching” Occupational Exposure” requirements[1].
Although hair dyes are safe for most ordinary people, the country still has strict regulations on this. Among the 75 kinds of hair dyes that are allowed to be used, the maximum allowed The concentration is in the range of 0.05%~4%. It can be said that as long as it is a qualified product, there is no problem in daily use [2].
In addition to hair dyes, “color developers” are also important in hair color products, often including strong oxidizing agents such as hydrogen peroxide and sodium perborate. These ingredients can not only oxidize the melanin in the hair to colorless, but also cause strong irritation to the skin, so many people feel that the scalp is “thorny” when they dye their hair.
Nowadays, many people like to buy hair coloring products from shopping websites, so there is a problem, the products bought are not necessarily regular, so It is recommended to buy from the brand’s official online store to buy, or you can buy products with anti-counterfeiting codes.
In addition, if you buy products produced abroad, some of the ingredient standards are likely to be different from the national standards, but as long as they are formal, there is generally no problem. So be sure to choose a reliable purchasing channel!
(Source: Internet)
1. Does dyeing hair cause cancer?
To be sure, the occasional coloring of your hair will not cause cancer.
However, it is not ruled out that frequent hair dyeing may increase the risk of cancer, so it is recommended to dye hair at most 2~3 times a year [1].
2. Is the lighter the color of the hair dye more harmful to the body?
In theory, all shades of hair dye have the same effect on the body. The key is that if you want to dye light-colored hair, in order to better color, you must first “bleach” the melanin in the hair. So the lighter you dye your hair, the longer it will take to bleach your hair.
For bleaching hair, a highly oxidative color developer is used. The longer the scalp and hair are exposed to the environment of strong oxidants, the more irritation and damage they will naturally suffer. The risk of allergy also increases [3].
3. About the pit of hair dyeing in barbershops
Tony, the teacher at the barber shop, always recommends a treatment before dyeing, or recommends more expensive pure plant hair dyes.
Is this an IQ tax?
In fact, there is a certain basis for scalp care before hair dyeing. As mentioned earlier, the color-developing agent in hair dyeing products will cause strong irritation to the scalp. If you apply it on the scalp properly beforehand products, which can play a certain role in isolation.
In the hairdressing circle, there is still a legend that it is best not to wash your hair before dyeing. This also makes sense. The oil secreted on the scalp and the metabolized keratin can play a certain role. [4].
While pure vegetable hair dyes are better than regular hair dyes, there is no convincing that the active ingredients in all hair dyes are similar to the chemicals mentioned above,
strong>If additional plant extracts with unknown contents are added, it may increase the risk of allergy[3].
4. Which is more suitable for home hair coloring or barber hair coloring
From an economic point of view, it is definitely more suitable to dye hair at home. The disadvantage is that it is time-consuming and labor-intensive, especially if the novice is not standardized and unskilled, not only the hair dyeing effect may be greatly reduced, but also the hair dye is easily contaminated Scalp, may cause bodily harm.
And the benefits of choosing a barber shop are also obvious. Professional barbers can better control hair color, decolorization time, and evenness of hair dye application. You only need to sit Just wait there to become beautiful, the disadvantage is that it costs a lot and is not very friendly to patients with social phobia…
1. Do not dye your hair if the scalp is inflamed or damaged.
2. Do not wash your hair two days before coloring.
3. Take protective measures before dyeing, apply Vaseline and other creams in advance on the ears, neck, hairline, etc., and do a good job of isolation.
4. Test for allergies 48 hours before dyeing, take a little hair dye, apply it to inconspicuous places such as behind the ears, and observe for a few minutes to see if there are allergy symptoms, if there is tingling , redness, peeling, please stop using.
5. Wash your hair several times after dyeing to remove the residual chemical ingredients.
If you’re at homedye, be extra careful:
1. It is best not to mix different brands and models of hair dye.
2. Confirm whether the amount of good hair coloring products is sufficient, so as to avoid the embarrassment that half of the hair coloring cream is gone.
3. Pay attention to timing. After applying hair dye, you can forget the time while playing with your phone!
If you dye your hair at a barbershop, be careful:
1. Before dyeing hair, ask about the brand of hair dyeing products and confirm that they are regular products.
2. Communicate clearly with the hairdresser in advance on the color of the dyed hair to avoid disagreements later.
3. Choose hair coloring products that suit your financial ability and consume rationally.
Okay, that’s it for today’s article, I hope it can help you who love beauty.
Reviewer: Shi Shuxian| Associate Professor, Laboratory of Bio-Environmental Materials, Beijing University of Chemical Technology
References
[1] He Congfen, Wei Shiyu. “Color Meter” directed by p-phenylenediamine [N]. China Medical News, 2019-12-18(003).
[2] “Technical Specifications for Cosmetics Safety” (2015 Edition), CFDA Announcement No. 268 of 2015. http:https://www.sda.gov.cn/WS01 /CL0087/140161.html . 2015.
[3] Chu Hong. Those things about hair dyeing [J]. Jiangsu Health Care, 2020(09):44-45.
[4] It is best not to wash your hair before dyeing [J]. Invention and Innovation (Big Tech), 2019(01):46.
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