The term dibutyl refers to a type of butyl ester classified as an aqueous hydrocarbon and member of the alkanes family, which means it is composed of carbon and hydrogen. As an alkane, dibutyl forms single bonds exclusively, giving the organic compound the generic chemical formula of CnH2n+2. However, this substance is also an isomer of octane, which means it is highly combustible and yields carbon dioxide and water when burned.
Once bonded, dibutyl esters may take various forms. For instance, dibutyl sebacate (DBS) is an ester of sebacic acid, a naturally occurring substance obtained from the volatile oil of the castor bean. DBS is a yellowish liquid that is insoluble in water but soluble in some solvents, including acetone, ethanol, and toluene. Its chemical composition renders a low combustion rating and helps it to preserve its properties when heated below certain temperatures. As such, DBS has an application as a plasticizer and is primarily used in the manufacture of plastic packaging and coatings, as well as to produce synthetic rubber.
DBS is also found in various consumable products. For instance, it is a food additive in many kinds of baked goods, hard candies, ice creams, and non-alcoholic beverages. It is also used to make the enteric coating on oral medications. DBS is also used as an emulsifying agent in skin lotions, hair conditioners, and shaving creams. In addition, DBS is added as a solvent to extract fragrance from various oils used to make perfumes, colognes, after shave lotions, and body splashes.
Another common type of ester is dibutyl phthalate (DBP), which is synthesized from butanol and phthalic anhydride. Like DBS, this substance is also used in the plastics industry as well as in the manufacturing of many types of cosmetics. In fact, its characteristics as a plasticizer made it a common ingredient in nail polish at one time. However, DBS has been found to have adverse effects on the endocrine system in animals and is suspected of posing similar risks in humans. Therefore, US manufacturers of nail polish began phasing out the use of DPB in 2006, while the European Union banned its use altogether thirty years earlier.
Unfortunately, DBP exposure may come from a variety of unexpected sources other than nail polish. In fact, one of the largest sources of exposure comes from food since it may leach out from containers and packaging used to wrap certain perishable goods. Since DBP can survive in the environment as a particle or gas, it is also found in varying concentrations in the air, soil, and water supply in industrial areas. Since DBP biodegrades rather quickly in water and soil, it is not likely to be transported to other regions. However, it can migrate in marine life since it accumulates in the fatty tissue of fish and shellfish.