The current concept of daily chemical consumption is increasingly concerned with the naturalness of products and the safety of raw materials. Consumers often raise concerns and questions about silicon-containing daily chemicals, such as "Does silicon-containing chemicals break pores, ruin skin, damage the body?" Because people have a little understanding of the "silicone", coupled with the concept of "silicone-free oil" and other marketing hype, let some consumers talk about "silicon" discoloration.
What is the "silicon" in the daily chemicals?


The word "silicon" in daily chemicals is basically polysiloxane, or silicon dioxide (less frequently). The English composition table is also very simple. The components ending in -cone or -siloxane are polysiloxanes, such as Cyclopentasiloxane, Dimethicone, Polysilicone-11, etc., and silica is silica.




In recent years, silicone rubber products have been recognized by many people, and good products that contact human skin. At present, more people choose to use silicone daily necessities, daily chemicals, etc. At present, silicone custom processing technology has matured, and organic silicone products are in the field of daily chemical industry. The application has developed rapidly and has become one of the main areas of silicone applications. Almost all personal care products contain silicone-containing products, and such highly functional functional materials continue to expand their applications with the advent of new products. Due to its easy-to-adjust functional properties and excellent sensory properties, and its use in environmental and consumer safety, it is increasingly being used to partially or completely replace organic materials in cosmetics and toiletries. Useful ingredients








Why add "silicon"


In order to make the makeup look beautiful, most of the makeup products in the makeup cream, foundation and other make-up products contain “silicon”. Many essences and oil-free creams in skin care products will also be added to “silicon”, especially the well-known department stores. Shop brand. Because these big brands usually attach great importance to skin feel, while "silicon" is not absorbed by the skin at all, it will not bring about any substantial skin care effect other than moisturizing, but it can provide immediate effect, such as smoothing, filling the pores. And wrinkles, as well as a refreshing and non-greasy upper face feel, so very popular with these brands. At the same time, because "silicon" will provide a smooth feeling, there are also in shampoo products. Mainly because polysiloxane is very safe and stable in the chemical field, it is not absorbed into the body, and it can be used safely for most people.








Silicone was first used in cosmetics since 1950, when the processing technology of silicone products was not mature. Dow Corning began to develop compounds in silicone content from latex, which can be integrated into the hand cream without affecting it. This product has an excellent effect on protecting the skin, which has caused people to pay attention to silicone oil cosmetics.




It was not until the 1980s that silicone surfactants developed rapidly and extensively. These surfactants have many unique advantages, such as low surface tension, good wetting and spreading properties, strong thermal stability, large emulsification, good compatibility, foaming, foam stabilization and foam suppression. It is non-toxic and has no side effects. It has been widely used in various industries and has become a widely used additive in cosmetics.




Silicone surfactants are a relatively large amount of surfactants used in the daily chemical industry and can be used in various cosmetics. It is used as an emulsifier in flavors and shampoos. It has the functions of emulsification, foaming, dispersing and solubilizing, which makes the shampoo foam rich, fine and stable, and has antistatic effect. Silicone surfactant has no side effects on the human body. It can form a protective film of fat layer on the skin surface to prevent dry skin. It is an excellent skin lubricant and moisturizer. It is especially suitable for formulating emulsifiers and emulsion stabilizers for facial and eye cosmetics. .








Common silicone ingredients for skin care products in China




The polyether type silicone surfactant is mainly composed, and the combined structure of the polysiloxane segment (A) and the polyether segment (B) is block AB type, block ABA or BAB type, block (AB) There are five types of n-type, branched-chain and side-chain types. There are two ways for the connection between the polyether segment and the silicon oxide segment, namely si-o-c type and s-c type. The former is unstable and belongs to hydrolysis type, and the latter is stable to water, which is called non-hydrolysis type.




The polyether silicone oil has the characteristics of water solubility, emulsifying property, surface activity and physiological inertness, and can be prepared into a personal protective product to obtain a colorless, odorless, non-irritating to the human body, and does not affect the normal breathing and sweating of the skin. Product. It also reduces the surface tension of cosmetics, helps spread on skin and hair, has moisturizing and retention properties, makes hair shiny, antistatic, and has good inhibition to bacteria. It is an excellent cosmetic auxiliaries.








The surface activity of the modified polysiloxane in the aqueous or oil phase depends on the type and amount of the modified gene. Oil-soluble silicones improve the diffusion of oils and paraffins and can be directly applied to cosmetic and skin care formulations: Modified hydrophilic silicones are mainly used in shampoo and foam solutions. In addition to the above silicone surfactants, folk alkyl-modified polysiloxanes, polysiloxane sulfonic acids, polysiloxane thiosulfates, and aminosilicones have also been used in cosmetics. The role of silicone surfactants in daily cosmetics has become more and more prominent, and it has become a kind of silicone products that are developing rapidly and worthy of attention. Cationic, anionic or nonionic silicone microemulsions can be used to produce cosmetics.




Is the "silicon" in the chemical products harmful?


First, the safety discussion


Since the application of silicone oil, research and discussion on its safety has been carried out. At present, there are a lot of research reports related to the safety of silicone oil, covering the impact on the environment, animals, plants and human body, from natural decomposition, biological metabolism, and Sensitivity, physical safety, chemical safety, toxicology and other aspects were analyzed. In 1976, the United States established the Cosmetic Ingredients Review (CIR), a systematic analysis and evaluation of silicone raw materials, which was released in 2003, 2011, 2014 and 2016, including linear polydimethylene. Safety reports on various silicone raw materials such as siloxanes indicate that silicone oil is a safe substance and can be used as a cosmetic raw material. In 2011, the European Chemical Industry Ecology and Toxicology Center (ECETOC) released a safety assessment report on linear polydimethylsiloxane, pointing out the safety risks of such silicone oil products to the environment, animals, plants and human body. Very low.








In January 2018, the EU Communiqué announced the amendment of European Commission 2018/35, which officially revised the Appendix XVII of the REACH Regulation, stipulating the rinsing cosmetics octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane. The content of the alkane (D5) component must be less than 0.1%. The revision of this regulation ends the dispute over the use of D4 and D5 for up to 10 years. The establishment of a concentration limit of 0.1% can effectively terminate the behavior of adding D4 and D5. No D4, D5" will become the standard for European-style rinse-off cosmetics. It can be seen that although there is no clear research data to prove the harm of D4 and D5, we can not deny its potential safety hazards.




Second, the safety of the human body


Human skin is not sensitive to various silicone oil materials, and the stimulating effect of silicone oil is weak. Some ring clustering silicone oil can be slightly absorbed by the skin, but it will not cause skin irritation and allergic reactions. Through clinical experiments, it was found that silicone oil had no significant effect on the human urinary system, digestive system and circulatory system. Longer-term clinical observation studies have shown that silicone oil does not increase the risk of cancer. The impact of current silicone on human immune stress is still inconclusive, but so far there is no clear evidence that silicone oil will affect the immune system. So far there is no experimental evidence that silicone oil materials have a significant negative impact on the human body.








Third, the impact on the environment


Linear silicone oil is difficult to degrade by microorganisms in nature, but it can be hydrolyzed in moist sand. The water-soluble oligomer can be further biodegraded into environmentally friendly substances such as carbon dioxide, water and inorganic silicate, indicating that it cannot be permanently in nature. presence. At the same time, China is carrying out environmental risk assessment for D4, D5 and D6, and silicone will follow the report.








Consumers choose daily chemicals, no need to talk about "silicon" color change


Silicone oil is very stable in the chemical field and can be used with confidence for most people. Although the safety of silicone oil has long been widely recognized and widely used in the industry, the market-oriented products with “silicone-free oil” as a marketing concept have also achieved a certain share.




Some consumers have misunderstandings about the daily chemical products containing silicone oil. They believe that the use of pores may cause blockage of the pores, which may hinder the body's water vapor discharge, which may cause symptoms such as hair loss, allergies and acne. However, the data shows that although the oil film formed by various silicone oils is waterproof, it does not significantly hinder the penetration of water vapor and air. On the contrary, it is recognized that the safe Vaseline is almost airtight. The specific data is shown in Table 2.








Table 2: In vitro test water vapor transmission rate data


The unique molecular structure of silicone oils determines the excellent physicochemical properties of such polymers. Advances in synthesis, purification and characterization techniques have greatly promoted the application of silicone oil in the chemical industry for decades. At the same time, research institutes, third-party institutions, silicone oil producers, and industry associations have conducted extensive research and evaluation on the safety of silicone oils in daily chemicals. According to the existing safety test data, the evaluation report of international authoritative organizations and the practical application of silicone oil in the pharmaceutical and food industries, it is indicated that silicone oil is safe in the existing use of daily chemicals.




Greening and mildening are the hotspots of silicone surfactants used in daily chemicals. Nowadays, people are increasingly demanding daily chemicals. For users, the lower the stimulation of silicone products, the better. It has such advantages. If it is properly modified, it will exhibit milder and more environmentally friendly characteristics, such as modification with bioactive groups such as sugar bases and amino acids, making silicone surfactants more susceptible to degradation and no skin. Side effects have even reached the standard requirements of the food grade.