Polysorbate 20 is a common ingredient in many everyday products, often leading to questions about its function, particularly whether it acts as a preservative. Found in numerous personal care and food products, its specific role is often misunderstood. This article clarifies what Polysorbate 20 truly does and its purpose.
What is Polysorbate 20?
Polysorbate 20 is a nonionic surfactant, meaning it reduces the surface tension between liquids or between a liquid and a solid. Chemically, it is an ethoxylated sorbitan monolaurate, derived from sorbitol, a sugar alcohol, and lauric acid, a fatty acid often sourced from coconut oil. The “20” in its name indicates the average number of polyethylene glycol units attached to the molecule.
This compound typically appears as a clear to yellowish viscous liquid. It is highly soluble in water and alcohol. Its molecular structure allows it to effectively interact with both oil and water components in a mixture.
The Role of Preservatives
Preservatives are substances added to products to prevent or slow down spoilage. Their primary function is to inhibit the growth of microorganisms such as bacteria, fungi, and yeast. This microbial growth can lead to product degradation, changes in appearance, texture, and odor, and potentially pose health risks to consumers.
Preservatives are necessary to extend the shelf life of various products, including cosmetics, foods, and pharmaceuticals. By controlling microbial contamination, they help maintain product quality and ensure safety. Chemical preservatives achieve this by directly interfering with microbial processes or creating an environment unsuitable for their proliferation.
Polysorbate 20: Beyond Preservation
Polysorbate 20 is not a preservative; it does not possess inherent antimicrobial properties to kill or inhibit microbial growth. Its mechanism of action differs significantly from that of true preservatives, which actively combat spoilage organisms. While Polysorbate 20 does not directly preserve products, its presence can indirectly contribute to product stability by preventing ingredient separation.
Its main functions are as an emulsifier, a solubilizer, and a wetting agent. As an emulsifier, it allows oil and water to mix and remain blended, forming stable emulsions, much like an ingredient in mayonnaise keeps oil and vinegar combined. As a solubilizer, it helps dissolve oil-soluble ingredients, such as fragrances or essential oils, into water-based formulations, ensuring clarity and even distribution. It also acts as a wetting agent, reducing surface tension to help liquids spread more easily or powders disperse better in a solution.
Common Uses and Safety Considerations
Polysorbate 20 is widely used across multiple industries due to its versatile properties. In cosmetics, it is found in products such as lotions, shampoos, facial cleansers, and body washes, where it helps combine water and oil phases and solubilize fragrances. In the food industry, it acts as an emulsifier in items like ice cream, baked goods, and salad dressings, preventing separation and improving texture. Pharmaceuticals also utilize Polysorbate 20 as an excipient to stabilize emulsions and suspensions.
Regulatory bodies like the U.S. Food and Drug Administration (FDA) have designated Polysorbate 20 as Generally Recognized As Safe (GRAS) for its intended uses in food. When used in typical product concentrations, it is considered safe for the average consumer. While some individuals might have sensitivities, Polysorbate 20 does not pose significant safety concerns for the vast majority in consumer products.