Butylated Hydroxytoluene (BHT)
BHT or butyl hydroxytoluene is a fat soluble synthetic compound which is commonly used to preserve foods and cosmetics to slow down the autoxidation rate of ingredients in a product that can cause changes in the taste or colour. As such, it is primarily used to prevent fats in foods from becoming rancid – but it is also used in cosmetics, pharmaceuticals, jet fuels, rubber, petroleum products, electrical transformer oil, and embalming fluid. BHT (butylated hydroxytoluene) is a lab-made chemical that is added to foods as a preservative. People also use it as medicine. BHT is used to treat genital herpes and acquired immunodeficiency syndrome (AIDS). Some people apply BHT directly to the skin for cold sores.
Butylated hydroxytoluene (BHT), also known as dibutylhydroxytoluene, is a lipophilic organic compound, chemically a derivative of phenol, that is useful for its antioxidant properties. European and U.S. regulations allow small amounts to be used as a food additive. In addition to this use, BHT is widely used to prevent oxidation in fluids (e.g. fuel, oil) and other materials where free radicals must be controlled.
Phytoplankton, including the green algae Botryococcus braunii, as well as three different cyanobacteria (Cylindrospermopsis raciborskii, Microcystis aeruginosa and Oscillatoria sp.) are capable of producing BHT. Confirmation was made via gas chromatography–mass spectrometry analysis.
BHT is listed under three categories in catalogues and databases, such as food additive, household product ingredient, industrial additive, personal care product/cosmetic ingredient, pesticide ingredient, plastic/Rubber ingredient and Medical/Veterinary/Research.
BHT is primarily used as an antioxidant food additive. In the United States, it is classified as generally recognized as safe (GRAS) based on a National Cancer Institute study from 1979 in rats and mice.It is approved for use in the U.S. by the Food and Drug.
BHT is also used as an antioxidant in products such as cosmetics, pharmaceuticals, rubber, electrical transformer oil (at 0.35%), and embalming fluid. In the petroleum industry, where BHT is known as the fuel additive AO-29, it is used in hydraulic fluids, turbine and gear oils, and jet fuels. BHT is also used to prevent peroxide formation in diethyl ether and other laboratory chemicals. Some additive products contain BHT as their primary ingredient, while others contain the chemical merely as a component of their formulation, sometimes alongside butylated hydroxyanisole (BHA).