:2-Butoxyethanol

Miscibility of 2-butoxyethanol with water depends on temperature. Depending on the composition of the mixture, the two liquids are partially miscible. This mixture shows both a lower and an upper critical solution temperature: below around 49 °C (lower critical solution temperature), the liquids are completely miscible. The same is true for temperatures above around 130 °C (upper critical solution temperature). Between these temperatures, however, the liquids do not mix in all proportions and two phases might appear, each of which is formed by various ratios of the two liquids.{{Cite journal |last=Christensen |first=Scott P. |last2=Donate |first2=Felipe A. |last3=Frank |first3=Timothy C. |last4=LaTulip |first4=Randy J. |last5=Wilson |first5=Loren C. |date=2005-05-01 |title=Mutual Solubility and Lower Critical Solution Temperature for Water + Glycol Ether Systems |url=https://pubs.acs.org/doi/full/10.1021/je049635u |journal=Journal of Chemical & Engineering Data |volume=50 |issue=3 |pages=869–877 |doi=10.1021/je049635u |issn=0021-9568|url-access=subscription }}{{Cite web |date=2024-12-07 |title=Liquid - Raoult's Law, Intermolecular Forces, Viscosity {{!}} Britannica |url=https://www.britannica.com/science/liquid-state-of-matter/Raoults-law#ref506848 |access-date=2025-01-05 |website=www.britannica.com |language=en}}

2-Butoxyethanol is commonly obtained through two processes; the ethoxylation reaction of butanol and ethylene oxide in the presence of a catalyst:

{{block indent|{{chem2|C2H4O + C4H9OH → C4H9OC2H4OH}} }}

or the etherification of butanol with 2-chloroethanol.{{cite book|title=Toxicological Profile for 2-Butoxyethanol and 2-butoxyethanol acetate|date=August 1998|publisher=U.S. Dept of Health and Human Services|author=Harris O.|display-authors=etal}} 2-Butoxyethanol can be obtained in the laboratory by performing a ring opening of 2-propyl-1,3-dioxolane with boron trichloride.{{cite journal|last1=Bonner|first1=Trevor|title=Opening of cyclic acetals by trichloro-, dichloro-, and tribromo-borane|journal=Journal of the Chemical Society, Perkin Transactions 1|date=1981|pages=1807–1810|doi=10.1039/p19810001807}} It is often produced industrially by combining ethylene glycol and butyraldehyde in a Parr reactor with palladium on carbon.{{citation|url= https://patents.google.com/patent/US8829229B2/en|last1=Tulchinsky|first1=Michael|title=Poly ethers and process for making them|date=2014}}

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.{{cite web|title=Ethylene Glycol Mono-N-Butyl Ether|url=http://toxnet.nlm.nih.gov/cgi-bin/sis/search/f?./temp/~0Bg03b:1|publisher=National Library of Medicine|access-date=2014-03-26}} In the US, it is considered a high production volume chemical because more than 100 million pounds of this chemical are produced per year.

2-Butoxyethanol is a glycol ether with modest surfactant properties, which can also be used as a mutual solvent.{{what|What is that?|date=July 2021}}

2-Butoxyethanol is a solvent for paints and surface coatings, as well as cleaning products and inks.{{cite web|url=http://www.sharpie.com/enus/Pages/FAQ.aspx#Q15|title=Sharpie Frequently Asked Questions|work=sharpie.com|access-date=30 June 2015|archive-url=https://web.archive.org/web/20150526212818/http://www.sharpie.com/enus/Pages/FAQ.aspx#Q15|archive-date=26 May 2015|url-status=dead}} 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 and glass cleaners, liquid soaps, cosmetics, dry cleaning solutions, lacquers, varnishes, herbicides, latex paints, enamels, printing paste, 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 polar and non-polar ends, 2-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.

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2-Butoxyethanol is commonly produced for the oil industry because of its surfactant properties.{{cite journal|last1=Rogers|first1=J|title=A Framework for Identifying Organic Compounds of Concern in Hydraulic Fracturing Fluids Based on Their Mobility and Persistence in Groundwater|journal=Environmental Science and Technology Letters|date=2015|volume=2|issue=6|pages=158–164|doi=10.1021/acs.estlett.5b00090|bibcode=2015EnSTL...2..158R|doi-access=free}}

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.{{Clarify|date=April 2014|reason = Toxnet searches expire quickly. It is unclear what source is being referred to from the search.}} 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 absorbs at the oil-water interface of the fracture.{{cite journal |last1=Barati |first1=Reza |title=A review of fracturing fluid systems used for hydraulic fracturing of oil and gas wells |journal=Journal of Applied Polymer Science |date=2014 |volume=131 |issue=16 |pages=n/a |doi=10.1002/app.40735|doi-access=free }} 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,{{Cite web|url = http://www.nalcoesllc.com/nes/documents/MSDS/NESLLC-COREXIT-_EC9527A-March_2012.pdf|archive-url = https://web.archive.org/web/20140502013531/http://www.nalcoesllc.com/nes/documents/MSDS/NESLLC-COREXIT-_EC9527A-March_2012.pdf|url-status = dead|archive-date = 2 May 2014|title = Safety Data Sheet - Product: Corexit EC9527A|access-date = 30 April 2014|publisher = Nalco Environmental Solutions LLC|date = 1 March 2012}}

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.Siegfried Rebsdat, Dieter Mayer "Ethylene Glycol" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2000.{{doi|10.1002/14356007.a10_101}}. 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.{{cite web|title=Toxicology and Carcinogenesis Studies 2-Butoxyethanol (CAS NO. 111-76-2) in F344/N Rats and B6C3F1 Mice (Inhalation Studies)|url=https://ntp.niehs.nih.gov/go/tr484abs|work=National Toxicology Program: Department of Health and Human Services|publisher=USA.gov|access-date=4 June 2010|archive-url=https://web.archive.org/web/20100528075034/http://ntp.niehs.nih.gov/?objectid=070AC403-B110-CA79-3A23AF79DE7B752A|archive-date=2010-05-28|url-status=dead}} American Conference of Governmental Industrial Hygienists (ACGIH) reports that 2-butoxyethanol is carcinogenic in rodents.{{cite web|title=Air Foam HD Material Data Safety Sheet|url=https://archive.org/details/AirFoamHdMaterialDataSafetySheetmsds|work=Product Safety|publisher=AquaClear, Inc|access-date=4 June 2010}} These rodent tests may not directly translate to carcinogenicity in humans, as the observed mechanism of cancer involves the rodents' forestomach, which humans lack.{{cite journal | author = Gift, J. S. | title = U.S. EPA's IRIS assessment of 2-Butoxyethanol: the relationship of noncancer to cancer effects | journal = Toxicol. Lett. | year = 2005 | volume = 156 | issue = 1 | pages = 163–178 | doi=10.1016/j.toxlet.2003.08.014| pmid = 15705494 | url = http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1168&context=usepapapers | url-access = subscription }} OSHA does not regulate 2-butoxyethanol as a carcinogen.{{cite web|title=Chemical Sampling Information {{!}} 2-Butoxyethanol|url=https://www.osha.gov/dts/chemicalsampling/data/CH_222400.html|publisher=Occupational Safety & Health Administration|access-date=2014-04-23|archive-date=2017-07-31|archive-url=https://web.archive.org/web/20170731224022/https://www.osha.gov/dts/chemicalsampling/data/CH_222400.html|url-status=dead}} 2-Butoxyethanol has not been shown to penetrate shale rock in a study conducted by Manz.{{cite journal|last1=Manz|first1=K|title=Adsorption of hydraulic fracturing fluid components 2-butoxyethanol and furfural onto granular activated carbon and shale rock|journal=Chemosphere|date=2016|volume=164|pages=585–592|doi=10.1016/j.chemosphere.2016.09.010|pmid=27632795|bibcode=2016Chmsp.164..585M}}

2-Butoxyethanol can be disposed of by incineration. It was shown that disposal occurs faster in the presence of semiconductor particles. 2-Butoxyethanol usually decomposes in the presence of air within a few days by reacting with oxygen radicals.{{Cite journal |last1=Hullar |first1=T. |last2=Anastasio |first2=C. |date=2011-07-22 |title=Yields of hydrogen peroxide from the reaction of hydroxyl radical with organic compounds in solution and ice |url=https://acp.copernicus.org/articles/11/7209/2011/ |journal=Atmospheric Chemistry and Physics |language=English |volume=11 |issue=14 |pages=7209–7222 |doi=10.5194/acp-11-7209-2011 |bibcode=2011ACP....11.7209H |issn=1680-7316|doi-access=free }} It has not been identified as a major environmental contaminant, nor is it known to bio-accumulate.{{cite web|url=https://wwwn.cdc.gov/TSP/ToxFAQs/ToxFAQsLanding.aspx?id=346&tid=61|title=ATSDR - ToxFAQs: 2-Butoxyethanol and 2-Butoxyethanol Acetate|work=cdc.gov|access-date=30 June 2015}} 2-Butoxyethanol biodegrades in soils and water, with a half life of 1–4 weeks in aquatic environments.

2-Butoxyethanol most commonly enters the human body system through dermal absorption, inhalation, or oral consumption of the chemical. The ACGIH threshold limit value (TLV) for worker exposure is 20 ppm, which is well above the odor detection threshold of 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.2009 TLVs and BEIs, American Conference of Industrial Hygienists, Cincinnati, Ohio, 2009, p.101.{{cite book | author = R. Baselt | title = Disposition of Toxic Drugs and Chemicals in Man | edition = 8th | publisher = Biomedical Publications | location = Foster City, CA | year = 2008 | pages = 208–210}} 2-Butoxyethanol and its metabolites fall to undetectable levels in urine after about 30 hours in men.

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 of laboratory 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.Wess, Ms. J., Dr. H. Ahlers, and Dr. S Dobson. "Concise International Chemical Assessment Document 10: 2-Butoxyethanol." World Health Organization, n.d. Web. 2-Butoxyethanol is metabolized in mammals by the enzyme alcohol dehydrogenase.{{cite journal |author1=Franks, S. J. |author2=Spendiff, M. K. |author3=Cocker, J. |author4=Loizou, G. D. | title = Physiologically based pharmacokinetic modelling of human exposure to 2-butoxyethanol | journal = Toxicol. Lett. | year = 2006 | volume = 162 |issue=2–3 | pages = 164–173 | doi=10.1016/j.toxlet.2005.09.012|pmid=16246510 }}

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.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.

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.

Environment and Health Canada recommended that 2-butoxyethanol be added to Schedule 1 of the Canadian Environmental Protection Act, 1999 (CEPA).{{cite web | title = Current Use Patterns in Canada, Toxicology Profiles of Alternatives, and the Feasibility of Performing an Exposure Assessment Survey | publisher = Environment Canada | url = http://www.chemicalsubstanceschimiques.gc.ca/fact-fait/butoxyethanol-eng.php | access-date= 15 February 2011 | date = 2017-03-12 }} 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.{{Cite web|url = http://www.gazette.gc.ca/rp-pr/p2/2014/2014-04-23/html/sor-dors78-eng.php|title = Regulations Amending the 2-Butoxyethanol Regulations|access-date = 30 April 2014|date = 23 April 2014|publisher = Canadian Department of Public Works and Government Services|website = Canada Gazette}}

2-Butoxyethanol is listed in California as a hazardous substance and the state sets an 8 hour average airborne concentration exposure limit at 25 ppm,{{cite web | url = http://www.dir.ca.gov/title8/339.html | title = California Code of Regulations, Title 8, Section 339. The Hazardous Substances List | access-date= 2008-04-21 | publisher = State of California Department of Laboring Relations | archive-url= https://web.archive.org/web/20080505040711/http://www.dir.ca.gov/title8/339.html| archive-date= 5 May 2008 | url-status= live}} and in California employers are required to inform employees when they are working with it.{{cite web | title = Glycol Ethers Fact Sheet | publisher = California Hazard Evaluation and Information Service | url = http://www.dhs.ca.gov/ohb/HESIS/glycols.htm | access-date = 29 October 2007 | archive-url = https://web.archive.org/web/20070818004042/http://www.dhs.ca.gov/ohb/HESIS/glycols.htm | archive-date = 18 August 2007 | url-status = dead | df = dmy-all }}

It is approved by the Food and Drug Administration as "an indirect and direct food additive for use as an antimicrobial agent, defoamer, stabilizer and component of adhesives", 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".CFR Title 21 - Food and Drugs - URL: http://www.fda.gov (2004). CFR Title: 21 CFR Part Section: 173.315 After its deletion from a UN list of substances requiring special toxicity labeling in 1994, and a subsequent petition by the American Chemistry Council, 2-butoxyethanol was removed from the U.S. Environmental Protection Agency's list of hazardous air pollutants in 2004.{{cite web | publisher = U.S. Environmental Protection Agency | url = https://www3.epa.gov/ttn/atw/pollutants/fr29no04.pdf | date = 2004-11-29 | title = List of Hazardous Air Pollutants, Petition Process, Lesser Quantity Designations, Source Category List; Petition To Delist of Ethylene Glycol Monobutyl Ether| access-date= 3 August 2024 }}{{Cite web|url = http://www.egep.org/worldsolutions2000.pdf|title = EGBE: A World of Solutions 2000|access-date = 30 April 2014|archive-date = 3 October 2006|date = July 2000|archive-url = https://web.archive.org/web/20061003060754/http://www.egep.org/worldsolutions2000.pdf}} The safety of products containing 2-butoxyethanol as normally used is defended by the industry trade groups the American Chemistry Council and the Soap and Detergent Association.

{{reflist|30em}}

• [http://www.inchem.org/documents/icsc/icsc/eics0059.htm International Chemical Safety Card 0059]
• [https://www.cdc.gov/niosh/npg/npgd0070.html NIOSH Pocket Guide to Chemical Hazards]
• [http://www.inchem.org/documents/sids/sids/111762.pdf Inchem SIDS dossier] {{Webarchive|url=https://web.archive.org/web/20160303210243/http://www.inchem.org/documents/sids/sids/111762.pdf |date=2016-03-03 }}
• [https://web.archive.org/web/20070928135619/http://www.eastman.com/Product_Information/ProductHome.asp?Product=71000130 Eastman EB solvent info]
• [https://wwwn.cdc.gov/TSP/ToxFAQs/ToxFAQsLanding.aspx?id=346&tid=61 ToxFAQs for 2-Butoxyethanol and 2-Butoxyethanol Acetate] from the Centers for Disease Control

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Category:Glycol ethers

Category:Hydroxyethyl compounds

Category:Household chemicals

Category:Cleaning products

Category:Butyl compounds