Was there a moment when you were young? At that time, a brand of anti-dandruff shampoo specially designed for the Asian market was patented with zinc pyrithione (ZPT), because the anti-dandruff effect was really good and it earned a lot of money.
But! ZPT was recently banned from the European Union. What the hell is going on?
65438+1On October 22nd, the European Commission formally submitted the circular G/TBT/N/EU/773 to the World Trade Organization. This notice is like thunder, and it is expected to affect most dandruff shampoos on the market. The circular lists ZPT, a commonly used anti-dandruff ingredient, as CMR 1B substance (based on animal research, it is assumed that it has carcinogenic, mutagenic and teratogenic effects on human body).
Although the European Union Scientific Committee on Consumer Safety (SCCS) stated in its conclusion on ZPT in 2020 that shampoo with ZPT content below 1% is safe; However, because ZPT is not an irreplaceable anti-dandruff ingredient (what are the alternative ingredients), it cannot meet the requirement of "irreplaceable raw materials" in EU cosmetics regulations. Therefore, ZPT cannot meet the exemption conditions for using CMR in cosmetics (if it is irreplaceable, it should be used even if it is toxic, but ZPT is not).
Based on the above reasons, the European Commission plans to delete ZPT from the list of restricted substances in cosmetics and the list of preservatives allowed in cosmetics, and at the same time include it in the list of prohibited substances in cosmetics.
Dandruff is a large number of desquamation caused by excessive proliferation of scalp keratinocytes. A survey report in 20 13 years shows that about 60% of adults in China suffer from dandruff in different degrees, of which 15% is very serious [1]. In 20 13 years, dandruff shampoo has accounted for more than 35% of the total amount of shampoo (although I think dandruff shampoo will be king in the near future).
A large number of studies have proved that Malassezia is closely related to the occurrence and severity of dandruff. The proliferation of Malassezia on the scalp causes excessive proliferation of the stratum corneum of the scalp, which makes the stratum corneum cells fall off abnormally in the form of white or gray scales, which is dandruff.
ZPT has strong antibacterial ability, can effectively kill dandruff-producing fungi (such as Malassezia), and has good dandruff removal function. In addition, it is also widely used in coatings and other aspects. For more than 60 years, ZPT has been used as a chip remover. [2]
At first, the European Union thought that ZPT with the concentration of 1% was safe when used in rinse hair products, and it could also be used as a preservative or a restricted substance for non-antiseptic use in cosmetics. The US Food and Drug Administration also believes that when ZPT is used in small amounts as a component of daily necessities, it is harmless to the human body. China's Technical Specification for Cosmetic Safety (20 15) also says that ZPT is suitable for dandruff removal and shampoo products, but the maximum concentration is 1.5%.
When ZPT is used externally, most of it can only stay in the outer layer of stratum corneum, some of it can be deposited in epidermis, or sebum dissolved in hair follicles remains in hair follicles, and almost no transdermal absorption occurs. ZPT can only decrease with the metabolism of stratum corneum, so it can play a lasting and safe antibacterial role.
Because of the poor skin permeability of ZPT, ZPT for external use in human body basically does not produce acute toxicity, and it is safe to use in the range of 65438 0% ~ 2%.
However, ZPT is embryotoxic to aquatic organisms.
ZPT will be discharged into water environment such as rivers together with domestic water. As a pollutant that may bring environmental risks, studies show that ZPT has acute toxicity to marine polychaetes at sublethal concentrations [3]. Studies by the National Institute of Environment of Japan show that shampoo containing ZPT can induce wave-like deformity in the back bone of fry [4].
In mammals, the embryotoxicity of ZPT has not been reported. In the 60 years since ZPT was used as an anti-dandruff ingredient, there has been no report on the toxicity of human embryos.
Octopirox (OCT) is a relatively new anti-dandruff agent, and no cytotoxicity has been reported in the past 30 years. It also achieves the purpose of removing dandruff by killing fungi, and the low concentration (0. 1%-0.75%) is effective. At present, this kind of anti-dandruff agent is often used in high-end anti-dandruff shampoo on the market because of its relatively high cost.
Clomibazole (CLM), also known as Garcinia cambogia, has a history of over 40 years. It is an antifungal compound, which can fight fungi by inhibiting the synthesis of fungal cell membrane. The EU limits the use of clomizole as a preservative in shampoo to 0.5% and as other ingredients to 2%. However, its anti-dandruff and antipruritic effect is far from that of ZPT and OCT, and its dosage has been decreasing in recent years.
Others, such as salicylic acid, sulfur, coal tar, selenium disulfide, etc. They can often be seen in anti-dandruff shampoos, but their sense of use is often not as good as that of shampoos that focus on the above two ingredients. Ketoconazole is also a common ingredient in anti-dandruff shampoo in pharmacies, but it needs to be used as a medicine under the guidance of a doctor.
Even though ZPT seems to be safe for human body at present, the earth has really reached the point where everyone needs to care. Many aquatic organisms are sensitive to the toxicity of ZPT. I don't think it is a bad thing to ban the use of ZPT in cosmetics.
Of course, it is still necessary to keep it in the medicine and use it under the supervision of a dermatologist, rather than diagnose it yourself. Severe dandruff can't be solved by shampoo. Leave the professional affairs to the professionals, and you can worry about it yourself.
If necessary, please contact sns@guokr.com.