Polysorbate 80 is a synthetic ingredient that is used in cosmetics and personal care products as a surfactant, emulsifier, and solubilizer.
Polysorbate 80 is produced by the ethoxylation of sorbitan. Sorbitan is the dehydrated form of sorbitol, a sugar alcohol that can naturally be found in some fruits. Ethoxylation is a chemical reaction in which ethylene oxide is added to a substrate (in this case, sorbitan). Sorbitan is reacted with 80 units of ethylene oxide (hence the 80 in the ingredient name). The final step is the addition of one oleic acid group esterified as the hydrophobic tail. Polysorbate 80 exists as a viscous, water-soluble yellow liquid.
In addition to its function in cosmetics, polysorbate 80 can be used to prepare a wide variety of products in the food, drug, textile, and metalworking industries.
In cosmetics and personal care products, polysorbate 80 functions as a surfactant, emulsifier, and solubilizer.
Polysorbate 80 is a nonionic surfactant, which means it has a neutral charge. A surfactant, or surface active agent, works by lowering the surface tension between two substances, such as two liquids or a liquid and a solid. A surfactant molecule contains one end that is hydrophilic (attracted to water) and one end that is lipophilic (attracted to oil). This allows surfactants to attract and suspends oils, dirt, and other impurities that have accumulated on the skin and wash them away. Due to these properties, polysorbate 80 can be found in many different cleansers and body washes.
Polysorbate 80 is also an emulsifier with an HLB value of 15. HLB (Hydrophile-Lipophile Balance) is an empirical expression for the relationship of the hydrophilic and lipophilic groups of a surfactant. An HLB of greater than 10 means that the substance is soluble in water.
As an emulsifier, polysorbate 80 is often used in formulations that contain both water and oil components. Mixing water and oil together creates a dispersion of oil droplets in water (and vice versa). However, these two phases can separate if the product is left to settle. To address this problem, an emulsifier like polysorbate 80 can be added to the system to help the droplets remain dispersed. Emulsifiers improve the consistency of a product, which enables an even distribution of topical skin care benefits.
Polysorbate 80 also functions as a solubilizer with a wide range of hydrophilic characteristics. It can be used individually, or in combination with a variety of other hydrophobic emulsifiers, to produce many different types of oil-in-water, and water-in-oil emulsion systems. When used alone, polysorbate 80 is an excellent solubilizer for essential oils and has good function as a wetting agent, viscosity modifier, anti-static agent, stabilizer, and dispersing agent. Polysorbate 80 can also improve the rinse off of anhydrous scrubs and cleansing oils.
The United States Food and Drug Administration (FDA) allows polysorbate 80 to be directly added to food as adjuvants of flavoring agents or as multipurpose additives. Additionally, polysorbate 80 has FDA approval as an ophthalmic demulcent and may be used in over-the-counter (OTC) ophthalmic drug products.
The safety of polysorbate 80 has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. The Panel evaluated the scientific data and concluded that polysorbate 80 was safe as cosmetic ingredients.
Despite the approval of polysorbate 80 by the CIR Expert Panel, there are concerns about the presence of ethylene oxide in this ingredient. This is because the process of ethoxylation may lead to contamination with 1,4-dioxane, a potentially dangerous by-product. In fact, 1,4-dioxane is a known animal carcinogen that penetrates readily into the skin. This ingredient has also been linked with skin allergies.
The Organic Consumers Organization released a fact sheet on 1,4-dioxane based on information from the Campaign for Safe Cosmetics. The fact sheet outlines facts versus myths regarding 1,4-dioxane in personal care products. One concerning fact is that the levels of 1,4-dioxane found in many personal care products are 1,000 times higher than those found to cause cancer in animal studies. They add that according to the FDA, “Skin absorption studies demonstrated that dioxane readily penetrates animal and human skin from various types of vehicles.”
References: Wikipedia, “Polysorbate 80”, Food Safety Commission, “Polysorbates”, 2007, Cosmetics Info, “Polysorbate 80”, Organic Consumers Organization, “1,4-Dioxane and Cosmetic Safety”.