Polysorbate 20

About This Product

Polysorbate 20 (CAS 9005-64-5), also called polyoxyethylene (20) sorbitan monolaurate, is a nonionic surfactant made by ethoxylating sorbitan monolaurate with an average of about 20 moles of ethylene oxide. Lauric acid, a saturated C12 fatty acid, forms the hydrophobic part, and the polyoxyethylene chains the hydrophilic part. The result is a lemon to amber, oily liquid with an HLB of about 16.7, readily soluble in water, ethanol and many polar solvents. The short, saturated lauric chain is what distinguishes polysorbate 20 from polysorbate 80. It makes the molecule more hydrophilic, so polysorbate 20 is a stronger solubiliser for small amounts of light oils, essential oils and fragrances in clear aqueous products, while polysorbate 80 is preferred for emulsifying heavier oils. The saturated chain also makes polysorbate 20 less prone to oxidation, although peroxide formation can still occur from the polyoxyethylene chains on long storage. In cosmetics and personal care, polysorbate 20 solubilises fragrance and botanical oils in toners, body mists, micellar waters, gels and room sprays, and it is used as a mild co-surfactant in baby shampoos and facial cleansers. In laboratories and diagnostics, high-purity grades are used as a blocking and wash agent in immunoassay buffers and to reduce non-specific binding. In pharmaceuticals, pharmacopoeia grades act as solubilisers and stabilisers. Industrial uses include wetting agents for cleaning products and agrochemicals, and emulsifiers in inks and coatings. Food grade (E432) is a separate product; confirm the grade before any regulated use. The parameters buyers agree are acid value, saponification value, hydroxyl value, water content and sometimes viscosity, peroxide value, residue on ignition and fatty-acid composition. The lauric acid content confirms the identity. Pharmaceutical and laboratory grades add limits on ethylene oxide, dioxane and other impurities. Record the agreed grade and limits in the purchase specification and compare each batch certificate against them. Polysorbate 20 is generally not classified as hazardous under CLP and is not regulated as dangerous goods for transport, but check sections 2 and 14 of the safety data sheet. Like other polysorbates, it is generally treated as a polymer under EU REACH and UK REACH, so registration applies to the monomers and reactants; an importer should confirm how these are covered. For cosmetic use, keep grade documents on file for the product information file. Store polysorbate 20 in closed containers in a cool, dry place, protected from light and air. It may become more viscous or hazy at low temperatures; warm gently and mix before use. Close part-used containers promptly to limit water absorption and oxidation. When you enquire, state the grade (technical, cosmetic, pharmacopoeia or laboratory), the application, key limits such as acid value, hydroxyl value and water, the pack format, your annual volume and the destination.