October 13, 2025 News As a "veteran ingredient" in the beauty and daily chemical industry, silicone oil has become a core helper for public hair care since Procter & Gamble introduced it into the shampoo field in the 1980s and launched revolutionary "2-in-1 shampoo and conditioner" products. Its hair care principles and safety have always attracted much attention. Silicone oil in shampoo is not a single substance, but a general term for polydimethylsiloxane and its derivatives. Common types include polydimethylsiloxane, polydimethylsiloxanol, amino-terminated polydimethylsiloxane, etc. Different types meet different hair care needs due to structural differences. Polydimethylsiloxane can quickly spread on hair strands and reduce friction; polydimethylsiloxanol can form hydrogen bonds with hair keratin through hydroxyl groups for firmer adhesion; amino silicone oil relies on positive and negative charge adsorption and becomes the preferred choice for repairing damaged hair. The hair care effect of silicone oil stems from its unique deposition and film-forming mechanism. When the natural protective film of the cuticle on the outer layer of hair is damaged, the hair will become frizzy and tangled. During shampooing, the flocculant formed after the shampoo is diluted will wrap the silicone oil and deposit it on the hair surface. The silicone oil then spreads to smooth the raised cuticles, fill the damaged gaps, and form a breathable protective film, which not only reduces water loss but also lowers hair friction, achieving the effect of smoothing and caring for hair. Regarding the safety concerns of consumers, professional institutions such as the US Cosmetic Ingredients Review (CIR) and the European Chemical Industry Ecology and Toxicology Center (ECETOC) have confirmed that silicone oil-based raw materials such as polydimethylsiloxane have extremely low safety risks and can be safely used in cosmetics. In the future, with technological upgrades, silicone oil will further meet personalized hair care needs and inject new vitality into the innovation of the shampoo and care industry.