Sodium dehydroacetate is a preservative that is used in the formulation of cosmetics and personal care products in order to extend the shelf-life by preventing microbial contamination.
Sodium dehydroacetate is the sodium salt of dehydroacetic acid, a fungicide and bactericide that is commonly used as a food preservative. Fungicides have the ability to kill parasitic fungi or their spores, whereas bactericides are capable of destroying bacteria. While dehydroacetic acid is an effective preservative, it is almost insoluble in water, which limits its use in cosmetics formulations. Sodium dehydroacetate has greater solubility in water, which is why it is often used in place of dehydroacetic acid in cosmetics and personal care products.
In addition to use in the cosmetic industry, sodium dehydroacetate can be used as a food preservative. It is used extensively in sauce, fruit, bread, cake, moon cake, margarine, and beverages. Sodium dehydroacetate has the E number E266. It is a white crystalline powder with no odor. It has good performance of light resistance and heat resistance.
In cosmetics and personal care products, sodium dehydroacetate functions as an antimicrobial preservative. It is used in a wide variety of products, including bath products, skin care products, sunscreens, fragrances, shaving products, hair and nail care products, as well as eye and facial makeup. Sodium dehydroacetate is an effective antimicrobial agent even at low concentrations (less than and equal to 0.6%) against both bacteria and fungi.
The use of preservatives in cosmetics is important because these types of products have a high potential for microbial contamination and growth. The most susceptible products are creams and lotions that are packaged in jars, opened frequently, and applied to the skin with the fingers. Inadvertent contamination may also occur after the use of makeup brushes around the eyes or other parts of the face that touch the skin and the cosmetic repeatedly. Each use increases the chance for contamination. Furthermore, contamination may occur if the consumer leaves a product container open for an extended period of time.
Storage conditions are also a major cause of microbial contamination in cosmetics and personal care products. Since the majority of products are stored at room temperature, the warm temperature can stimulate the growth of microorganisms. Plus, the ingredients used in cosmetic formulations, such as water, oils, peptides, and carbohydrates, create the perfect environment for microorganism growth.
Microbial contamination can lead to significant health problems, from skin irritation to infections. To avoid these problems, a strong yet non-irritating preservative must be added to the formulation of a product. Sodium dehydroacetate fits boths of these criteria. The use of sodium dehydroacetate in cosmetic formulations ensures that the product performs effectively over the time it takes the consumer to finish the product.
The safety of sodium dehydroacetate has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. Numerous clinical tests has demonstrated that sodium dehydroacetate is non-irritating, non-sensitizing, non-photosensitizing, and non-phototoxic. After evaluating the scientific data, the CIR Expert Panel concluded that sodium dehydroacetate was safe as a cosmetic ingredient in the present practices of use and concentration.
The safety of sodium dehydroacetate has also been evaluated and rated on EWG’s Skin Deep Cosmetic Database. According to the Cosmetic Database, sodium dehydroacetate is rated as a 1 on a scale of 1 to 10, with 1 being the lowest risk to health and 10 being the highest.
References: Wikipedia “Dehydroacetic acid”, Cosmetics Info “Sodium dehydroacetate”, EWG’s Skin Deep Cosmetic Database “Sodium dehydroacetate”