2-Butoxyethanol
![]() | |
![]() | |
Names | |
---|---|
Preferred IUPAC name
2-Butoxyethanol | |
Other names
2-Butoxyethanol
Butyl cellosolve Butyl glycol Butyl monoether glycol EGBE (ethyleneglycol monobutylether) Dowanol EB Eastman EB solvent 2-BE EGMBE Butyl oxitol Ektasolve EB Jeffersol EB | |
Identifiers | |
3D model (JSmol)
|
|
ChEBI | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.003.550 |
EC Number |
|
PubChemCID
|
|
RTECS number |
|
UNII | |
UN number | 1993, 2810, 2369 |
CompTox Dashboard(EPA)
|
|
| |
| |
Properties | |
C6H14O2 | |
Molar mass | 118.176g·mol−1 |
Appearance | Clear, colorless liquid |
Density | 0.90 g/cm3,liquid |
Melting point | −77 °C (−107 °F; 196 K) |
Boiling point | 171 °C (340 °F; 444 K) |
Miscible (and in most organic solvents) | |
Vapor pressure | 0.8 mmHg[1] |
Acidity(pKa) | High pKafor −OH group |
Refractive index(nD)
|
1.4198 (20 °C)[2] |
Viscosity | 2.9 cPat 25 °C (77 °F) |
2.08D[2] | |
Hazards | |
GHSlabelling: | |
![]() ![]() ![]() | |
Danger | |
H227,H302,H311,H315,H319,H330,H336,H361,H370,H372 | |
P201,P202,P210,P260,P261,P264,P270,P271,P280,P281,P284,P301+P312,P302+P352,P304+P340,P305+P351+P338,P307+P311,P308+P313,P310,P312,P314,P320,P321,P322,P330,P332+P313,P337+P313,P361,P362,P363,P370+P378,P403+P233,P403+P235,P405,P501 | |
NFPA 704(fire diamond) | |
Flash point | 67 °C (153 °F; 340 K) |
245 °C (473 °F; 518 K) | |
Explosive limits | 1.1–12.7%[1] |
Lethal doseor concentration (LD, LC): | |
LD50(median dose)
|
1230 mg/kg (mouse, oral) 470 mg/kg (rat, oral) 300 mg/kg (rabbit, oral) 1200 mg/kg (guinea pig, oral) 1480 mg/kg (rat, oral)[3] |
LC50(median concentration)
|
450 ppm (rat, 4 hr) 700 ppm (mouse, 7 hr)[3] |
NIOSH(US health exposure limits): | |
PEL(Permissible)
|
TWA 50 ppm (240 mg/m3) [skin][1] |
REL(Recommended)
|
TWA 5 ppm (24 mg/m3) [skin][1] |
IDLH(Immediate danger)
|
700 ppm[1] |
Safety data sheet(SDS) | [1] |
Related compounds | |
Relatedethers
|
2-Methoxyethanol 2-Ethoxyethanol |
Related compounds
|
Ethylene glycol |
Except where otherwise noted, data are given for materials in theirstandard state(at 25 °C [77 °F], 100 kPa).
|
2-Butoxyethanolis anorganic compoundwith thechemical formulaBuOC2H4OH(Bu =CH3CH2CH2CH2). This colorless liquid has a sweet,ether-like odor, as it derives from the family ofglycol ethers,and is a butyl ether ofethylene glycol.As a relatively nonvolatile, inexpensive solvent, it is used in many domestic and industrial products because of its properties as asurfactant.It is a known respiratory irritant[4]and can be acutely toxic, but animal studies did not find it to be mutagenic, and no studies suggest it is a human carcinogen.[5]A study of 13 classroom air contaminants conducted in Portugal reported a statistically significant association with increased rates of nasal obstruction and a positive association below the level of statistical significance with a higher risk of obese asthma and increased body mass index.[6]
Production
[edit]2-Butoxyethanol is commonly obtained through two processes; theethoxylationreaction ofbutanolandethylene oxidein the presence of a catalyst:
or theetherificationof butanol with2-chloroethanol.[7]2-Butoxyethanol can be obtained in the laboratory by performing a ring opening of 2-propyl-1,3-dioxolane with boron trichloride.[8]It is often produced industrially by combining ethylene glycol and butyraldehyde in a Parr reactor with palladium on carbon.[9]
In 2006, theEuropeanproduction of butyl glycol ethers amounted to 181kilotons,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[10]and 18% for metal cleaners and household cleaners.[11]In the US, it is considered ahigh production volume chemicalbecause more than 100 million pounds of this chemical are produced per year.[11]
Uses
[edit]2-Butoxyethanol is a glycol ether with modestsurfactantproperties, which can also be used as a mutual solvent.[clarification needed]
Commercial uses
[edit]2-Butoxyethanol is a solvent forpaintsand surface coatings, as well as cleaning products andinks.[10][12]Products that contain 2-butoxyethanol includeacrylic resinformulations,asphaltrelease agents,firefighting foam,leather protectors,oil spilldispersants, degreaser applications, photographic strip solutions,whiteboardand glass cleaners, liquidsoaps,cosmetics,dry cleaningsolutions,lacquers,varnishes,herbicides,latex paints,enamels,printing paste, varnish removers, andsilicone 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 hasboth polar and non-polarends, 2-butoxyethanol is useful for removingbothpolarandnon-polarsubstances, like grease and oils. It is also approved by theU.S. FDAto be used as direct and indirect food additives, which includeantimicrobialagents,defoamers,stabilizers, and adhesives.[13]
In the petroleum industry
[edit]2-Butoxyethanol is commonly produced for the oil industry because of its surfactant properties.[14]
In the petroleum industry, 2-butoxyethanol is a component offracturing fluids,drilling stabilizers,and oil slickdispersantsfor both water-based and oil-basedhydraulic fracturing.[11][clarification needed]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.[11]As a surfactant, 2-butoxyethanol absorbs at the oil-water interface of the fracture.[15]The compound is also used to facilitate the release of the gas by preventing congealing.[11]It is also used as a crude oil–water coupling solvent for more generaloil well workovers.[11]Because of itssurfactantproperties, it is a major constituent (30–60% w/w) in the oil spilldispersantCorexit9527,[16]which was widely used in the aftermath of the 2010Deepwater Horizon oil spill.[13]
Safety
[edit]2-Butoxyethanol has a low acute toxicity, withLD50of 2.5 g/kg in rats.[10]Laboratory tests by theU.S. National Toxicology Programhave shown that only sustained exposure to high concentrations (100–500 ppm) of 2-butoxyethanol can cause adrenal tumors in animals.[17]American Conference of Governmental Industrial Hygienists (ACGIH) reports that 2-butoxyethanol is carcinogenic in rodents.[18]These rodent tests may not directly translate to carcinogenicity in humans, as the observed mechanism of cancer involves the rodents' forestomach, which humans lack.[19]OSHAdoes not regulate 2-butoxyethanol as a carcinogen.[20]2-Butoxyethanol has not been shown to penetrate shale rock in a study conducted by Manz.[21]
Disposal and degradation
[edit]2-Butoxyethanol can be disposed of byincineration.It was shown that disposal occurs faster in the presence ofsemiconductorparticles.[7]2-Butoxyethanol usually decomposes in the presence of air within a few days by reacting with oxygen radicals.[22]It has not been identified as a major environmental contaminant, nor is it known to bio-accumulate.[23]2-Butoxyethanol biodegrades in soils and water, with a half life of 1–4 weeks in aquatic environments.[13]
Human exposure
[edit]2-Butoxyethanol most commonly enters the human body system through dermal absorption, inhalation, or oral consumption of the chemical.[7]TheACGIHthreshold limit value(TLV) for worker exposure is 20 ppm, which is well above theodor detection thresholdof 0.4 ppm. Blood or urine concentrations of 2-butoxyethanol or the metabolite 2-butoxyacetic acid may be measured using chromatographic techniques. A biological exposure index of 200 mg 2-butoxyacetic acid per g creatinine has been established in an end-of-shift urine specimen for U.S. employees.[24][25]2-Butoxyethanol and its metabolites fall to undetectable levels in urine after about 30 hours in men.[26]
Animal studies
[edit]Harmful effects have been observed in nonhuman mammals exposed to high levels of 2-butoxyethanol. Developmental effects were seen in a study that exposed pregnant Fischer 344 rats, a type oflaboratory rat,and New Zealand white rabbits to varying doses of 2-butoxyethanol. At 100 ppm (483 mg/m3) and 200 ppm (966 mg/m3) exposure, statistically significant increases were observed in the number of litters with skeletal defects. Additionally, 2-butoxyethanol was associated with a significant decrease in maternal body weight, uterine weight, and number of total implants.[27]2-Butoxyethanol is metabolized in mammals by the enzymealcohol dehydrogenase.[26]
Neurological effects have also been observed in animals exposed to 2-butoxyethanol. Fischer 344 rats exposed to 2-butoxyethanol at concentrations of 523 ppm and 867 ppm experienced decreased coordination. Male rabbits showed a loss of coordination and equilibrium after exposure to 400 ppm of 2-butoxyethanol for two days.[28]
When exposed to 2-butoxyethanol in drinking water, both F344/N rats and B63F1 mice showed negative effects. The range of exposure for the two species was between 70 mg/kg body weight per day to 1300 mg/kg body weight per day. Decreased body weight and water consumption were seen for both species. Rats had reduced red blood cell counts and thymus weights, as well as lesions in the liver, spleen, and bone marrow.[27]
Regulation in Canada
[edit]Environment and Health Canada recommended that 2-butoxyethanol be added to Schedule 1 of theCanadian Environmental Protection Act, 1999(CEPA).[29]Under these regulations, products containing 2-butoxyethanol are to be diluted below a certain concentration. Only those in which the user performs the required dilution are required to include it on labelling information.[30]
Regulation in the US
[edit]2-Butoxyethanol is listed inCaliforniaas a hazardous substance and the state sets an 8 hour average airborne concentration exposure limit at 25 ppm,[31]and in California employers are required to inform employees when they are working with it.[32]
It is approved by theFood and Drug Administrationas "an indirect and direct food additive for use as an antimicrobial agent, defoamer, stabilizer and component of adhesives",[13]and also "may be used to wash or assist in the peeling of fruits and vegetables" and "may be safely used as components of articles intended for use in packaging, transporting & holding food".[33]After its deletion from a UN list of substances requiring special toxicity labeling in 1994, and a subsequent petition by theAmerican Chemistry Council,2-butoxyethanol was removed from theU.S. Environmental Protection Agency's list of hazardous air pollutants in 2004.[34][35]The safety of products containing 2-butoxyethanol as normally used is defended by theindustry trade groupstheAmerican Chemistry Council[35]and theSoap and Detergent Association.
References
[edit]- ^abcdeNIOSH Pocket Guide to Chemical Hazards."#0070".National Institute for Occupational Safety and Health(NIOSH).
- ^abWilliam M. Haynes, ed. (2016).CRC handbook of chemistry and physics: a ready-reference book of chemical and physical data(97th ed.). Boca Raton, Florida: CRC Press.ISBN978-1-4987-5428-6.OCLC930681942.
- ^ab"2-Butoxyethanol".Immediately Dangerous to Life or Health Concentrations (IDLH).National Institute for Occupational Safety and Health(NIOSH).
- ^"Toxnet Has Moved".www.nlm.nih.gov.Retrieved2020-01-24.
- ^"Public Health Statement for 2-Butoxyethanol and 2-Butoxyethanol Acetate".Agency for Toxic Substances and Disease Registry, Center for Disease Control.August 1998.Retrieved16 February2020.
- ^Paciência, Inês; Cavaleiro Rufo, João; Silva, Diana; Martins, Carla; Mendes, Francisca; Farraia, Mariana; Delgado, Luís; De Oliveira Fernandes, Eduardo; Padrão, Patrícia; Moreira, Pedro; Severo, Milton; Barros, Henrique; Moreira, André (2019). "Exposure to indoor endocrine-disrupting chemicals and childhood asthma and obesity".Allergy.74(7): 1277–1291.doi:10.1111/all.13740.PMID30740706.S2CID73443692.
- ^abcHarris O.; et al. (August 1998).Toxicological Profile for 2-Butoxyethanol and 2-butoxyethanol acetate.U.S. Dept of Health and Human Services.
- ^Bonner, Trevor (1981). "Opening of cyclic acetals by trichloro-, dichloro-, and tribromo-borane".Journal of the Chemical Society, Perkin Transactions 1:1807–1810.doi:10.1039/p19810001807.
- ^Tulchinsky, Michael (2014),Poly ethers and process for making them
- ^abcSiegfried Rebsdat, Dieter Mayer "Ethylene Glycol" inUllmann's Encyclopedia of Industrial Chemistry,Wiley-VCH, Weinheim, 2000.doi:10.1002/14356007.a10_101.
- ^abcdef"Ethylene Glycol Mono-N-Butyl Ether".National Library of Medicine.Retrieved2014-03-26.
- ^"Sharpie Frequently Asked Questions".sharpie.com.Archived fromthe originalon 26 May 2015.Retrieved30 June2015.
- ^abcd Dickey, Robert W.; Dickhoff, Walton W. (2012-01-30) [2011]."Dispersants and Seafood Safety Assessment of the potential impact of COREXIT oil dispersants on seafood safety"(PDF).Coastal Response Research Center (CRRC). (White Paper). Mobile, Alabama: Dispersant Initiative and Workshop “The Future of Dispersant Use in Spill Response” (Tuesday, September 20, 2011 to Thursday, September 22, 2011).Archived(PDF)from the original on 2021-04-12.Retrieved2022-08-03.
- ^Rogers, J (2015)."A Framework for Identifying Organic Compounds of Concern in Hydraulic Fracturing Fluids Based on Their Mobility and Persistence in Groundwater".Environmental Science and Technology Letters.2(6): 158–164.Bibcode:2015EnSTL...2..158R.doi:10.1021/acs.estlett.5b00090.
- ^Barati, Reza (2014)."A review of fracturing fluid systems used for hydraulic fracturing of oil and gas wells".Journal of Applied Polymer Science.131(16): n/a.doi:10.1002/app.40735.
- ^"Safety Data Sheet - Product: Corexit EC9527A"(PDF).Nalco Environmental Solutions LLC.1 March 2012. Archived fromthe original(PDF)on 2 May 2014.Retrieved30 April2014.
- ^"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. Archived fromthe originalon 2010-05-28.Retrieved4 June2010.
- ^"Air Foam HD Material Data Safety Sheet".Product Safety.AquaClear, Inc.Retrieved4 June2010.
- ^Gift, J. S. (2005)."U.S. EPA's IRIS assessment of 2-Butoxyethanol: the relationship of noncancer to cancer effects".Toxicol. Lett.156(1): 163–178.doi:10.1016/j.toxlet.2003.08.014.PMID15705494.
- ^"Chemical Sampling Information | 2-Butoxyethanol".Occupational Safety & Health Administration. Archived fromthe originalon 2017-07-31.Retrieved2014-04-23.
- ^Manz, K (2016). "Adsorption of hydraulic fracturing fluid components 2-butoxyethanol and furfural onto granular activated carbon and shale rock".Chemosphere.164:585–592.Bibcode:2016Chmsp.164..585M.doi:10.1016/j.chemosphere.2016.09.010.PMID27632795.
- ^Hullar, T.; Anastasio, C. (2011-07-22)."Yields of hydrogen peroxide from the reaction of hydroxyl radical with organic compounds in solution and ice".Atmospheric Chemistry and Physics.11(14): 7209–7222.Bibcode:2011ACP....11.7209H.doi:10.5194/acp-11-7209-2011.ISSN1680-7316.
- ^"ATSDR - ToxFAQs: 2-Butoxyethanol and 2-Butoxyethanol Acetate".cdc.gov.Retrieved30 June2015.
- ^2009 TLVs and BEIs,American Conference of Industrial Hygienists, Cincinnati, Ohio, 2009, p.101.
- ^R. Baselt (2008).Disposition of Toxic Drugs and Chemicals in Man(8th ed.). Foster City, CA: Biomedical Publications. pp. 208–210.
- ^abFranks, S. J.; Spendiff, M. K.; Cocker, J.; Loizou, G. D. (2006). "Physiologically based pharmacokinetic modelling of human exposure to 2-butoxyethanol".Toxicol. Lett.162(2–3): 164–173.doi:10.1016/j.toxlet.2005.09.012.PMID16246510.
- ^abWess, Ms. J., Dr. H. Ahlers, and Dr. S Dobson. "Concise International Chemical Assessment Document 10: 2-Butoxyethanol." World Health Organization, n.d. Web. <http://www.who.int/ipcs/publications/cicad/cicad_10_revised.pdf>
- ^United States of America. Agency for Toxic Substances and Disease Registry. Department of Health and Human Services. Toxicological Profile for 2-Butoxyethanol and 2-Butoxyethanol Acetate. By Olivia Harris, Sharon Wilbur, Julia George, and Carol Eisenmann. Atlanta: n.p., 1998. Agency for Toxic Substances and Disease Registry. Web. <http://www.atsdr.cdc.gov/toxprofiles/tp118.pdf>
- ^"Current Use Patterns in Canada, Toxicology Profiles of Alternatives, and the Feasibility of Performing an Exposure Assessment Survey".Environment Canada. 2017-03-12.Retrieved15 February2011.
- ^"Regulations Amending the 2-Butoxyethanol Regulations".Canada Gazette.Canadian Department of Public Works and Government Services. 23 April 2014.Retrieved30 April2014.
- ^"California Code of Regulations, Title 8, Section 339. The Hazardous Substances List".State of California Department of Laboring Relations.Archivedfrom the original on 5 May 2008.Retrieved2008-04-21.
- ^"Glycol Ethers Fact Sheet".California Hazard Evaluation and Information Service. Archived fromthe originalon 18 August 2007.Retrieved29 October2007.
- ^CFR Title 21 - Food and Drugs - URL:http://www.fda.gov(2004). CFR Title: 21 CFR Part Section: 173.315
- ^"List of Hazardous Air Pollutants, Petition Process, Lesser Quantity Designations, Source Category List; Petition To Delist of Ethylene Glycol Monobutyl Ether"(PDF).U.S. Environmental Protection Agency.2004-11-29.Retrieved3 August2024.
- ^ab"EGBE: A World of Solutions 2000"(PDF).July 2000. Archived fromthe original(PDF)on 3 October 2006.Retrieved30 April2014.