|Jmol-3D images||Image 1|
|Molar mass||118.17 g mol−1|
|Appearance||Clear, colourless liquid|
|Density||0.90 g/cm³, liquid|
|Melting point||−77 °C; −107 °F; 196 K|
|Boiling point||171 °C; 340 °F; 444 K|
|Solubility in water||Miscible|
|Acidity (pKa)||high pKa for -OH group|
|Viscosity||2.9 cP at 25 °C (77 °F)|
|MSDS||MSDS by Mallinckrodt Baker|
|EU classification||Harmful (Xn)|
|S-phrases||(S2), S36/37, S46|
|Flash point||67 °C; 153 °F; 340 K|
|Autoignition temperature||245 °C; 473 °F; 518 K|
|Related compounds||Ethylene glycol|
| (what is: / ?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C or 77 °F, 100 kPa)
2-Butoxyethanol is an organic compound with the formula BuOC2H4OH (Bu = CH3CH2CH2CH2). It is a colorless liquid with a sweet, ether-like odour. It is a butyl ether of ethylene glycol. It is a relatively nonvolatile, inexpensive solvent with modest surfactant properties.
- C2H4O + BuOH → BuOC2H4OH
In 2006, the European production of butyl glycol ethers amounted to 181 kilotons. Approximately 50% (90 kt/a) of which was 2-butoxyethanol. World production is estimated to be 200 to 500 kt/a, of which 75% is for paints and coatings.
2-Butoxyethanol is a solvent in paints and surface coatings, as well as cleaning products and inks. Other products that contain 2-butoxyethanol include acrylic resin formulations, asphalt release agents, firefighting foam, leather protectors, oil spill dispersants, degreaser applications, and photographic strip solutions. Other products containing 2-butoxyethanol as a primary ingredient include some whiteboard cleaners, liquid soaps, cosmetics, dry cleaning solutions, lacquers, varnishes, herbicides, and latex paints.
2-Butoxyethanol is frequently found in popular cleaning products. It is the main ingredient of many home, commercial and industrial cleaning solutions. Since it has both a non-polar and a polar end, it is useful for removing both polar and non-polar substances, like grease and oils.
Butoxyethanol has an LD50 of 2.5g/kg in rats. Laboratory tests by the United States 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) also reports that 2-butoxyethanol is carcinogenic in animals. However, these rodent tests may not directly translate to carcinogenicity in humans, as the observed mechanism of cancer involves the rodents' forestomach, which humans do not have.  OSHA does not regulate 2-butoxyethanol as a carcinogen; however, it should be handled as a carcinogen with extreme caution.
Moderate respiratory exposure to 2-butoxyethanol often results in irritation of mucous membranes of the eyes, nose and throat. Heavy exposure via respiratory, dermal or oral routes can lead to hypotension, metabolic acidosis, hemolysis, pulmonary edema and coma. The current ACGIH threshold limit value (TLV) for worker exposure is 20 ppm in the industrial atmosphere, which is well above the odor threshold of 0.4 ppm. 2-butoxyethanol is metabolized in animals by the enzyme alcohol dehydrogenase. Blood or urine concentrations of 2-butoxyethanol or its major toxic metabolite, 2-butoxyacetic acid, may be measured using chromatographic techniques to monitor worker exposure or to confirm a diagnosis of poisoning in hospitalized patients. A biological exposure index of 200 mg 2-butoxyacetic acid per g creatinine has been established in an end-of-shift urine specimen for exposed U.S. employees. 2-butoxyethanol and its metabolites fall to undetectable levels in urine after about 30 hours in human males.
U.S. Employers are required to inform employees when they are working with this substance.
Butoxyethanol is listed in the U.S. state of California as a hazardous substance, though it was removed from the U.S. Environmental Protection Agency's list of hazardous air pollutants in 1994.
2-Butoxyethanol has come under scrutiny in Canada, and Environment and Health Canada recommended that it be added to Schedule 1 of the Canadian Environmental Protection Act (CEPA). These products are not required to list it on the label when diluted to a certain point. The safety of the products as normally used is defended by the American Chemistry Council and the Soap and Detergent Association, industry trade groups.
2-Butoxyethanol usually decomposes in the presence of air within a few days by reacting with oxygen radicals. It has not been identified as a major environmental contaminant, nor is it known to bio-accumulate.
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