2-Butoxyethanol

2-Butoxyethanol
IUPAC name 2-Butoxyethanol
Other names butyl cellosolve butyl glycol ethylene glycol monobutyl ether Dowanol Bane-Clene Eastman EB solvent BH-33 industrial cleaner
Identifiers
CAS number	111-76-2 Y
ChemSpider	7841 Y
UNII	I0P9XEZ9WV Y
RTECS number	KJ8575000
Jmol-3D images	Image 1
SMILES OCCOCCCC
Properties
Molecular formula	C6H14O2
Molar mass	118.17 g mol−1
Appearance	Clear, colourless liquid
Density	0.90 g/cm³, liquid
Melting point	-77 °C, 196 K, -107 °F
Boiling point	171 °C, 444 K, 340 °F
Solubility in water	Miscible
Acidity (pKa)	high pKa for -OH group
Viscosity	2.9 cP at 25 °C (77 °F)
Hazards
MSDS	MSDS by Mallinckrodt Baker
EU classification	Harmful (Xn)
R-phrases	R20/21/22, R36/38
S-phrases	(S2), S36/37, S46
NFPA 704	2 2 0
Flash point	67 °C (153 °F)
Autoignition temperature	245 °C
Related compounds
Related ethers	2-Methoxyethanol 2-Ethoxyethanol
Related compounds	Ethylene glycol
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

2-Butoxyethanol is an organic solvent 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.

Production

2-Butoxyethanol is produced by monoethoxylation of butanol:

C₂H₄O + BuOH → BuOC₂H₄OH

In 2006, the total European production of all butyl glycol ethers amounted to 181 kilotons per annum (kt/a), 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.^{[citation needed]}

Uses

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.^[1][2] It is the main ingredient of many home, commercial and industrial cleaning solutions.

Safety

Butoxyethanol has an LD₅₀ of 2.5g/kg in rats.^[3] Laboratory tests by the United States National Toxicology Program have shown that sustained inhalation of high concentrations (100 - 500 ppm) of 2-butoxyethanol can cause adrenal tumors in animals.^[4] American Conference of Governmental Industrial Hygienists (ACGIH) reports that 2-butoxyethanol is carcinogenic in animals.^[5] OSHA does not regulate 2-butoxyethanol as a carcinogen,^{[citation needed]} however, it should be handled as a carcinogen with extreme caution. ^[6]

Human exposure

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. 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.^[7][8]

U.S. Employers are required to inform employees when they are working with this substance.^[9]

Butoxyethanol is listed in the U.S. state of California as a hazardous substance,^[10] though it was removed from the U.S. Environmental Protection Agency‎'s list of hazardous air pollutants in 1994.^[11]

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).^[12] The use of some common household cleaning products containing 2-butoxyethanol could expose people to levels 12 times greater than California's one-hour guideline, especially when indoor use is considered.^[1] 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.

Environment

2-Butoxyethanol usually decomposes in the presence of air within a few days and has not been identified as a major environmental contaminant. It is not known to bioaccumulate.^[13]

References

1. ^ ^{a b} Jane Kay (2007-07-24). "Hazard warning on home cleaners: Study says many use chemicals linked to fertility problems". San Francisco Chronicle. http://www.sfgate.com/cgi-bin/article.cgi?file=/c/a/2007/07/24/HAZARDS.TMP&tsp=1. 
2. ^ Alexandra Gorman. "Potential Hazards of Home Cleaning Products". Women's Voices for the Earth. http://www.womenandenvironment.org/campaignsandprograms/SafeCleaning/HazardsReport.pdf. 
3. ^ Siegfried Rebsdat, Dieter Mayer "Ethylene Oxide" in Ullmann's Encyclopedia of Industrial Chemistry Wiley-VCH, Weinheim, 2005.doi:10.1002/14356007.a10_117.
4. ^ "Toxicology and Carcinogenesis Studies 2-Butoxyethanol (CAS NO. 111-76-2) in F344/N Rats and B6C3F1 Mice (Inhalation Studies)". National Toxicology Program: Department of Health and Human Services. USA.gov. http://ntp.niehs.nih.gov/?objectid=070AC403-B110-CA79-3A23AF79DE7B752A. Retrieved 4 June 2010. 
5. ^ "Air Foam HD Material Data Safety Sheet". Product Safety. AquaClear, Inc. http://ia331209.us.archive.org/0/items/AirFoamHdMaterialDataSafetySheetmsds/. Retrieved 4 June 2010. 
6. ^ http://nj.gov/health/eoh/rtkweb/documents/fs/0275.pdf
7. ^ 2009 TLVs and BEIs, American Conference of Industrial Hygienists, Cincinnati, Ohio, 2009, p.101.
8. ^ R. Baselt, Disposition of Toxic Drugs and Chemicals in Man, 8th edition, Biomedical Publications, Foster City, CA, 2008, pp. 208-210.
9. ^ "Glycol Ethers Fact Sheet". California Hazard Evaluation and Information Service. http://www.dhs.ca.gov/ohb/HESIS/glycols.htm. 
10. ^ "California Code of Regulations, Title 8, Section 339. The Hazardous Substances List". State of California Department of Labor Relations. http://www.dir.ca.gov/title8/339.html. Retrieved 2008-04-21. 
11. ^ "List of Hazardous Air Pollutants, Petition Process, Lesser Quantity Designations, Source Category List; Petition To Delist of Ethylene Glycol Monobutyl Ether". U.S. Environmental Protection Agency. 2004-11-29. http://www.epa.gov/EPA-AIR/2004/November/Day-29/a26071.htm. 
12. ^ "Current Use Patterns in Canada, Toxicology Profiles of Alternatives, and the Feasibility of Performing an Exposure Assessment Survey". Environment Canada. http://www.chemicalsubstanceschimiques.gc.ca/fact-fait/butoxyethanol-eng.php. 
13. ^ Agency for Toxic Substances and Disease Registry ToxFAQs

External links

• International Chemical Safety Card 0059
• NIOSH Pocket Guide to Chemical Hazards
• Inchem SIDS dossier
• Eastman EB solvent info
• ToxFAQs for 2-Butoxyethanol and 2-Butoxyethanol Acetate from the Centers for Disease Control
• Toxicological Profile for 2-Butoxyethanol and 2-Butoxyethanol Acetate, from the CDC