2-Butoxyethanol

2-Butoxyethanol is an organic compound with the chemical formula BuOC2H4OH (Bu = CH3CH2CH2CH2). This colorless liquid has a sweet, ether-like odor, as it derives from the family of glycol ethers, and is a butyl ether of ethylene glycol. As a relatively nonvolatile, inexpensive solvent of low toxicity, it is used in many domestic and industrial products because of its properties as a surfactant. 2-Butoxyethanol is an organic compound with the chemical formula BuOC2H4OH (Bu = CH3CH2CH2CH2). This colorless liquid has a sweet, ether-like odor, as it derives from the family of glycol ethers, and is a butyl ether of ethylene glycol. As a relatively nonvolatile, inexpensive solvent of low toxicity, it is used in many domestic and industrial products because of its properties as a surfactant. 2-Butoxyethanol is commonly obtained through two processes; the ethoxylation reaction of butanol and ethylene oxide in the presence of a catalyst: or the etherification of butanol with 2-chloroethanol. 2-butoxyethanol can be obtained in the laboratory by performing a ring opening of 2-propyl-1,3-dioxolane with boron trichloride. It is often produced industrially by combining ethylene glycol and butyraldehyde in a Parr reactor with palladium on carbon. In 2006, the European production of butyl glycol ethers amounted to 181 kilotons, of which approximately 50% (90 kt/a) was 2-Butoxyethanol. World production is estimated to be 200 to 500 kt/a, of which 75% is for paints and coatings and 18% for metal cleaners and household cleaners. In the US, it is considered a High Production Volume Chemical because greater than 100 million pounds of this chemical is produced per year. 2-Butoxyethanol is a glycol ether with modest surfactant properties (and it can be used as a mutual solvent). In use since the 1930s, glycol ethers are solvents that dissolve both water-soluble and hydrophobic substances. Glycol ethers consist of two components, an alcohol and ether. According to the nature of alcohol, molecules of this class can be divided into two groups: E series and P series which correspond to ethylene and propylene respectively. Glycol ethers are selected for specific purposes, such as solubility, inflammability, and volatility. 2-Butoxyethanol is a solvent for paints and surface coatings, as well as cleaning products and inks. Products that contain 2-butoxyethanol include acrylic resin formulations, asphalt release agents, firefighting foam, leather protectors, oil spill dispersants, degreaser applications, photographic strip solutions, whiteboard cleaners, liquid soaps, cosmetics, dry cleaning solutions, lacquers, varnishes, herbicides, latex paints, enamels, printing paste, and varnish removers, and silicone caulk. Products containing this compound are commonly found at construction sites, automobile repair shops, print shops, and facilities that produce sterilizing and cleaning products. It is the main ingredient of many home, commercial and industrial cleaning solutions. Since the molecule has both non-polar and polar ends, butoxyethanol is useful for removing both polar and non-polar substances, like grease and oils. It is also approved by the U.S. FDA to be used as direct and indirect food additives, which include antimicrobial agents, defoamers, stabilizers, and adhesives. 2-Butoxyethanol is commonly produced for the oil industry because of its surfactant properties. In the petroleum industry, 2-butoxyethanol is a component of fracturing fluids, drilling stabilizers, and oil slick dispersants for both water-based and oil-based hydraulic fracturing When liquid is pumped into the well, the fracturing fluids are pumped under extreme pressure, so 2-butoxyethanol is used to stabilize them by lowering the surface tension. As a surfactant, 2-butoxyethanol adsorbs at the oil-water interface of the fracture. The compound is also used to facilitate the release of the gas by preventing congealing. It is also used as a crude oil-water coupling solvent for more general oil well workovers. Because of its surfactant properties, it is a major constituent (30–60% w/w) in the oil spill dispersant Corexit 9527, which was widely used in the aftermath of the 2010 Deepwater Horizon oil spill. 2-Butoxyethanol has a low acute toxicity, with LD50 of 2.5 g/kg in rats. Laboratory tests by the U. S. National Toxicology Program have shown that only sustained exposure to high concentrations (100-500 ppm) of 2-butoxyethanol can cause adrenal tumors in animals. American Conference of Governmental Industrial Hygienists (ACGIH) reports that 2-butoxyethanol is carcinogenic in rodents. These rodent tests may not directly translate to carcinogenicity in humans, as the observed mechanism of cancer involves the rodents' forestomach, which humans lack. OSHA does not regulate 2-butoxyethanol as a carcinogen. 2-butoxyethanol has not been shown to penetrate shale rock in a study conducted by Manz.As a regularly encountered chemical in the home, 2-butoxyethanol may be a human endocrine disruptor.