At present, the daily consumer goods concept pays more and more attention to the naturalness of products and the safety of raw materials. Consumers often raise various concerns and doubts about silicon-containing daily chemicals, such as "Does silicon-containing daily chemicals block the pores, damage the skin, and damage the body?" And so on. As people's understanding of "organic silicon" is poorly understood, coupled with the hype of conceptual marketing such as "silicone-free", some consumers are talking about the "silicon" discoloration.






What is "silicon" in daily chemicals


The daily chemical products with the word "silicon" are basically polysiloxane or silicon dioxide (less common). The English composition table is also very simple. The components ending with -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 are good products that touch the human skin. At present, more people choose to use silicone daily necessities, daily chemicals, etc. At present, the custom processing technology of silicone has matured, and organic silicone products have been used in the field of daily chemicals The rapid development of applications has become one of the main areas of organic silicon applications. Almost all personal care products have siloxane-containing products, and such widely applicable functional raw materials have been expanding their application fields with the advent of new products. Because siloxane has easy-to-adjust functional properties and excellent sensory properties, and its use is beneficial to the environment and consumer safety, it is increasingly being used to partially or completely replace organic raw materials in cosmetics and cleaning products. Useful ingredients








Why add "silicon"


In order to make the makeup beautiful, most of the base makeup products in makeup such as creams and foundations contain "silicone". Many essences and oil-free creams in skin care products will also be added with "silicon", especially the well-known department stores. Shop brand. Because these big brands usually attach great importance to skin feel, and although "silicon" will not be absorbed by the skin at all, it will not bring any substantial skin care effects other than moisturizing, but it can provide immediate results such as smoothness and fill pores And wrinkles, as well as refreshing and non-greasy feeling on the face, so they are very popular with these brands. At the same time, because "silicon" will provide a smooth feel, it is also available in shampoos. Mainly because polysiloxane is very safe and stable in the chemical field, and it is not easily absorbed into the body, it can be used safely for most people.








Silicone was first used in cosmetics from 1950, that is, the processing technology of silicone products has not yet matured. Dow Corning has gradually developed compounds in silicone content from latex, which can be integrated with hand cream without affecting. This product has an excellent effect on protecting the skin, which has aroused people's attention to silicone oil cosmetics.




It was not until the 1980s that silicone surfactants developed rapidly and on a large scale. Such surfactants have many unique advantages, such as low surface tension, good wetting and spreadability, strong thermal stability, large emulsification, good compatibility, and foaming, foam stabilization, and foam suppression, and 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 surfactant is a large amount of surfactant in the daily chemical industry, which can be used in various cosmetics. Used as an emulsifier in perfumes and shampoos. It has the effects of emulsification, foaming, dispersion and solubilization, can make the shampoo foam rich, finely stable, and has antistatic effect. Silicone surfactants have no side effects on the human body. They can form a protective layer of fatty layers on the surface of the skin and prevent skin dryness. They are excellent skin lubricants and humectants. They are especially suitable for formulating emulsifiers and emulsion stabilizers for facial and eye cosmetics .








Silicone ingredients commonly used in skin care products in China




Mainly polyether silicone surfactants, the combined structure of polysiloxane segment (A) and polyether segment (B) includes block AB type, block ABA or BAB type, and block (AB) 5 types including n-type, branch-chain type and side-chain type. There are two ways to connect the polyether segment and the silicone segment, namely the si-o-c type and the s-c type. The former is unstable and belongs to the hydrolysis type, while the latter is stable to water and is called non-hydrolyzed type.




Using polyether silicone oil with the characteristics of water solubility, emulsification, surface activity and physiological inertness, it can be formulated into personal protection products to be colorless, tasteless, non-irritating to the human body, and does not affect the normal breathing and sweating of the skin. Product. It can also reduce the surface tension of cosmetics, which is conducive to spread on the skin and hair. It has moisturizing and retention properties, makes the hair shiny, antistatic, and has good antibacterial activity. It is an excellent cosmetic additive.








The surface activity of modified polysiloxane in water phase or oil phase depends on the type and number of modified genes. Oil-soluble polysiloxanes can improve the diffusion ability of oil and paraffin, and can be directly applied to cosmetics and skin care formulations: modified hydrophilic polysiloxanes are mainly used in the formulation of shampoos and foam solutions. In addition to the above-mentioned silicone surfactants, civilian-chain alkyl-modified polysiloxanes, polysiloxane sulfonic acids, polysiloxane thiosulfates, and aminosiloxanes have also been used in cosmetics. Polysiloxane surfactants have become more and more prominent in daily cosmetics, and have become a class of silicone products that are developing rapidly and are worthy of attention. Cationic, anionic or non-ionic silicone microemulsions can be used in the production of cosmetics.




The "silicon" in daily chemicals is harmful?


I. Security Discussion


Since the application of silicone oil, research and discussion on its safety have been ongoing. At present, there have been a large number of research reports related to the safety of silicone oil, covering the impact on the environment, animals and plants, and the human body. Sensitivity, physical safety, chemical safety, toxicology and other perspectives were analyzed. The United States established the Cosmetic Ingredient Evaluation Expert Group (CIR) in 1976. The Evaluation Expert Group conducted a systematic analysis and evaluation of silicone raw materials. In 2003, 2011, 2014, and 2016, it released linear polydimethylamines. Silicone and other silicone raw material safety reports include that silicone oil is a safe substance and can be used as a raw material for cosmetics. In 2011, European Chemical Industry Ecology and Toxicology Center (ECETOC) released a safety assessment report on linear polydimethylsiloxane, pointing out the safety risks of this type of silicone oil products to the environment, animals and plants, and humans Very low.








In January 2018, the EU Gazette promulgated the European Commission's amendment 2018/35, which officially revised the appendix XVII of the REACH regulation to provide octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane for rinse-off cosmetics. The content of alkane (D5) must be less than 0.1%. This revision of the law ended the dispute over the use of D4 and D5 for up to 10 years. At the same time, the establishment of a concentration limit of 0.1% can effectively terminate the addition of D4 and D5. " "D4, D5" will become the standard for rinsing cosmetics in Europe. It can be seen that although there is no clear research data to prove the harm of D4 and D5, we cannot deny its potential safety hazard.




Human safety impact


Human skin is not sensitive to various silicone oil materials, and the stimulating effect of silicone oil is weak. Part of the ring cluster silicone oil can be absorbed percutaneously, but it will not cause skin irritation and allergic reactions. It has been found through clinical experiments that silicone oil has 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. At present, the effect of silicone on human immune stress is inconclusive, but 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.








Impact on the environment


Linear silicone oil is difficult to be degraded by microorganisms in nature, but can be hydrolyzed in moist sandy soil. This water-soluble oligomer can be further biodegraded into environmentally friendly substances such as carbon dioxide, water and inorganic silicates, indicating that it cannot be permanent in nature. presence. At the same time, China is conducting an environmental risk assessment of D4, D5, and D6, and organic silicon will follow-up reports.








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


Silicone oil is very stable in the chemical field, and it can be used safely for most people. Although the safety of silicone oil has been widely recognized and widely used in the industry, products with a marketing concept of "silicone-free" in the market have also reached a certain share.




Some consumers have misunderstandings about silicone oil-containing daily chemicals. They believe that after use, it will cause pores to be blocked, hinder the discharge of water vapor from the body, and 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 will not cause significant obstruction to the penetration of water vapor and air. On the contrary, the petroleum jelly, which is generally recognized as safe, is almost impermeable to air. See Table 2 for specific data.








Table 2: Data of water vapor transmission rate in vitro test


The unique molecular structure of silicone oil determines the excellent physical and chemical properties of these polymers. For decades, advances in synthesis, purification, and characterization technologies have greatly promoted the application of silicone oils in the daily chemical industry. At the same time, worldwide research institutes, third-party institutions, silicone oil manufacturers, and industry associations have done a lot of research and evaluation on the safety of silicone oil in daily chemical applications. According to the existing safety experimental data, the evaluation reports of international authoritative organizations, and the practical application of silicone oil in the pharmaceutical and food industries, it has been shown that silicone oil is safe in the current use of daily chemicals.




Greening and mildening is a hot spot in the application of silicone surfactants in daily chemical industry. Nowadays, people have increasingly higher requirements for daily chemicals. For users, the lower the stimulation of silicone products, the better. It has such advantages. If it is properly modified, it will show more mild and environmentally friendly characteristics, such as modification with biologically active groups such as sugar groups and amino acids, making the silicone surfactant more easily degraded and without any effect on the skin. Side effects have even reached the requirements of food grade standards.