Cosmetic silicone oil: Scientific Consensus and Safety Analysis

1.The basic functions and applications of silicone oil
Silicone oil, as a widely used ingredient in cosmetics, plays an irreplaceable role in skin care and hair care due to its unique physical and chemical properties. Its molecular structure endows the product with a silky smooth touch. For instance, in sunscreen, it can reduce the stickiness of zinc oxide, and in foundation, it achieves a long-lasting, lightweight texture. Laboratory data shows that adding just 0.3% silicone oil can significantly enhance the extensibility of the lotion, which is also the key to the silk-like touch of high-end skin care products. In addition, silicone oil forms a nano-scale protective film in hair care products, effectively repairing damage to the cuticles, reducing the coefficient of friction, and enhancing the luster and anti-breakage ability of the hair.

2. The Origin of Disputes and Progress in Scientific Research
Silicone oil once raised consumers' concerns due to rumors such as "clogging pores" and "causing hair loss". However, scientific research indicates that silicone oils with larger molecular weights cannot penetrate the stratum corneum (pores with diameters of approximately 20-50μm), and a 10-year follow-up study by the Japanese Dermatology Association shows that the pore blockage rate of silicone oil users has actually decreased by 12%. Both the US FDA and the Cosmetic Ingredient Review (CIR) agency have confirmed that silicone oil has undergone strict toxicological tests and no carcinogenic, mutagenic or teratogenic risks have been found. Its median lethal dose is even higher than that of table salt. Professional pharmacists point out that hair loss is mainly related to stress and health issues. The trace amounts of silicone oil in shampoos are difficult to penetrate the scalp, and modern water-soluble silicone oil designs have significantly reduced residues.

3. The positions and standards of regulatory authorities
Global regulatory authorities hold a clear supportive attitude towards the safety of silicone oil. The FDA has included silicone oil in the list of cosmetic ingredients and allowed its use within the compliant scope. Although the European Union will comprehensively restrict the consumer application of volatile silicone oils D4, D5 and D6 by 2026, this move is more based on environmental considerations rather than health risks. It is worth noting that the non-volatile application of silicone oil in hair care products is still permitted, and the industry is reducing its environmental impact through technological upgrades (such as temperature-sensitive intelligent silicone oil and green preparation processes).

4. How should consumers rationally view the composition of silicone oil
For ordinary consumers, choosing products containing silicone oil should be based on their own needs. For hair damaged by perming and dyeing, hair care products containing silicone oil can be given priority. The repair effect has been confirmed by experiments. People with oily scalps or those who seek a fluffy look can try silicon-free products. Experts suggest that the selection of ingredients should be based on scientific understanding rather than marketing labels. For instance, the degree of hair damage can be evaluated through methods such as traction tests and static electricity detection, and then the type of silicone oil (such as amino-modified silicone oil and medium-chain silicone oil) can be selected specifically. After all, the value of silicone oil lies in its precise molecular-level repair ability, rather than simply being labeled as "silicon-containing" or "silicon-free".