View source for Isopropyl alcohol

{{Short description|Simplest secondary alcohol}}
{{Use dmy dates|date=November 2023}} 
{{chembox
| Watchedfields  = changed
| verifiedrevid  = 477002700
| Name           = 
| ImageFileL1    = 2-Propanol.svg
| ImageNameL1    = Skeletal formula of isopropyl alcohol
| ImageFileR1    = Propan-2-ol-3D-balls.png
| ImageNameR1    = Ball-and-stick model of isopropyl alcohol
| ImageFile2     = Isopropanol by Danny S.jpg
| ImageSize2     = 100px
| PIN            = Propan-2-ol<ref name=iupac2013>{{cite book | title = Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book) | publisher = [[Royal Society of Chemistry|The Royal Society of Chemistry]] | date = 2014 | location = Cambridge | page = 631 | doi = 10.1039/9781849733069 | isbn = 978-0-85404-182-4 | last1 = Favre | first1 = Henri A. | last2 = Powell | first2 = Warren H. }}</ref>
| SystematicName = 
| OtherNames     = 2-Propanol<br />Isopropanol<ref name=iupac1979>{{Cite book| title = Nomenclature of Organic Chemistry (The IUPAC 'Blue Book'), Sections A, B, C, D, E, F, and H| year = 1979 | publisher = Pergamon Press | location = Oxford | chapter = Alcohols Rule C-201.1 | quote = Designations such as isopropanol, sec-butanol, and tert-butanol are incorrect because there are no hydrocarbons isopropane, sec-butane, and tert-butane to which the suffix "-ol" can be added; such names should be abandoned. Isopropyl alcohol, sec-butyl alcohol, and tert-butyl alcohol are, however, permissible (see Rule C-201.3) because the radicals isopropyl, sec-butyl, and tert-butyl do exist.}}</ref><br />[[Rubbing alcohol]]<br />''sec''-Propyl alcohol<br />2-Hydroxypropane<br />''i''-PrOH<br>Dimethyl carbinol<br />IPA
| IUPACName      = 
| Section1       = {{Chembox Identifiers
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 17824
| SMILES = CC(O)C
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = ND2M416302
| UNNumber = 1219
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 582
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C3H7OH/c1-3(2)4/h3-4H,1-2H3
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = KFZMGEQAYNKOFK-UHFFFAOYSA-N
| CASNo = 67-63-0
| CASNo_Ref = {{cascite|correct|CAS}}
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 3644
| PubChem = 3776
| RTECS = NT8050000
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = D00137
| Gmelin = 1464
| Beilstein = 635639
 }}
| Section2 = {{Chembox Properties
| C=3|H=8|O=1
| MolarMassUnit = g/mol
| Appearance = Colorless liquid
| Odor = Pungent alcoholic odor
| Density = 0.786{{nbsp}}g/cm<sup>3</sup> (20{{nbsp}}°C)
| Solubility = [[Miscible]] with water
| SolubleOther = Miscible with [[benzene]], [[chloroform]], [[ethanol]], [[diethyl ether]], [[glycerol]]; soluble in [[acetone]]
| MeltingPtC = −89
| BoilingPtC = 82.6
| pKa = 16.5<ref>{{cite journal |author1=Reeve, W. |author2=Erikson, C. M. |author3=Aluotto, P. F. |journal = Can. J. Chem. |year = 1979 |volume = 57 |issue = 20 |pages = 2747–2754 |doi = 10.1139/v79-444 |title = A new method for the determination of the relative acidities of alcohols in alcoholic solutions. The nucleophilicities and competitive reactivities of alkoxides and phenoxides |doi-access = free }}</ref>
| Viscosity = 2.86{{nbsp}}[[Poise (unit)|cP]] at 15{{nbsp}}°C<br/>1.96{{nbsp}}[[Poise (unit)|cP]] at 25{{nbsp}}°C<ref name = yaws>{{cite book |title = Chemical Properties Handbook |author = Yaws, C.L. |publisher = [[McGraw-Hill]] |year = 1999 |isbn = 978-0-07-073401-2 }}</ref><br/>1.77 c[[Poise (unit)|P]] at 30 °C<ref name = yaws/>
| Dipole = 1.66{{nbsp}}[[Debye|D]] (gas)
| RefractIndex = 1.3776
| MagSus = −45.794·10<sup>−6</sup>{{nbsp}}cm<sup>3</sup>/mol
| LogP = −0.16<ref name="chemsrc">{{Cite web |url=https://www.chemsrc.com/en/cas/67-63-0_766167.html |title=Isopropanol_msds |publisher=chemsrc.com |access-date=2018-05-04 |archive-date=2020-03-10 |archive-url=https://web.archive.org/web/20200310065358/https://www.chemsrc.com/en/cas/67-63-0_766167.html |url-status=live }}</ref>
 }}
| Section3       = 
| Section4       = 
| Section5       = 
| Section6       = {{Chembox Pharmacology
| ATCCode_prefix = D08
| ATCCode_suffix = AX05
}}
| Section7       = {{Chembox Hazards
| ExternalSDS = [https://www.mysafetylabels.com/chemical-label/isopropyl-alcohol-nfpa-label/sku-lb-1591-074?engine=bingshopping&keyword=Safety+Labels&skuid=LB-1591-074-RUG-CHE-2x3]
| MainHazards = Flammable, mildly toxic<ref>Isopropyl alcohol toxicity</ref>
| ExploLimits = 2–12.7%
| GHSPictograms = {{GHS exclamation mark}} {{GHS flame}}
| GHSSignalWord = '''Danger'''
| HPhrases = {{H-phrases|225|302|319|336}}
| PPhrases = {{P-phrases|210|261|305+351+338}}
| NFPA-H = 1 <!--http://www.telecheminternational.com/IPA_Reagent_ACS.PDF-->
| NFPA-F = 3
| NFPA-R = 0
| AutoignitionPtC = 399
| FlashPt = Open cup:
| FlashPtC = 11.7
| FlashPt_notes = <br/>Closed cup: {{convert|13|C|F}}
| TLV-TWA = 980{{nbsp}}mg/m<sup>3</sup>
| TLV-STEL = 1225{{nbsp}}mg/m<sup>3</sup>
| LD50 = {{ubl
 | 12800{{nbsp}}mg/kg (dermal, rabbit)<ref name=IDLH/>
 | 3600{{nbsp}}mg/kg (oral, mouse)
 | 5000{{nbsp}}mg/kg (oral, rat)<ref name=IDLH/>
 | 2364{{nbsp}}mg/kg (oral, rabbit)
 }}
| PEL = {{abbr|TWA|Time-weighted average}} 400{{nbsp}}ppm (980{{nbsp}}mg/m<sup>3</sup>)<ref name=PGCH>{{PGCH|0359}}</ref>
| IDLH = 2000{{nbsp}}ppm<ref name=PGCH/>
| REL = TWA 400{{nbsp}}ppm (980{{nbsp}}mg/m<sup>3</sup>), {{abbr|ST|short-term}} 500{{nbsp}}ppm (1225 mg/m<sup>3</sup>)<ref name=PGCH/> 
| LC50 = {{ubl
 | 53,000{{nbsp}}mg/m<sup>3</sup> (inhalation, mouse){{citation needed|date=July 2015}}
 | 12,000{{nbsp}}ppm (rat, 8{{nbsp}}[[hour|h]])<ref name=IDLH>{{IDLH|67630|Isopropyl alcohol}}</ref>
 }}
| LCLo = {{ubl
 | 16,000{{nbsp}}ppm (rat, 4{{nbsp}}h)
 | 12,800{{nbsp}}ppm (mouse, 3{{nbsp}}h)<ref name=IDLH/>
 }}
 }}
| Section8       = {{Chembox Related
| OtherFunction_label = [[Alcohol (chemistry)|alcohol]]s
| OtherFunction = [[1-Propanol]], [[ethanol]], [[2-butanol]]
 }}
}}

'''Isopropyl alcohol''' ([[International Union of Pure and Applied Chemistry|IUPAC]] name '''propan-2-ol''' and also called '''isopropanol''' or '''2-propanol''') is a [[Transparency and translucency|colorless]], [[Flammability|flammable]], [[organic compound]] with a pungent alcoholic [[odor]].<ref name=PubChem>{{cite web |url=https://pubchem.ncbi.nlm.nih.gov/compound/isopropanol |website=PubChem |title=Isopropanol |access-date=February 10, 2019 |archive-date=February 12, 2019 |archive-url=https://web.archive.org/web/20190212011452/https://pubchem.ncbi.nlm.nih.gov/compound/isopropanol |url-status=live }}</ref>

Isopropyl alcohol, an organic [[polar molecule]], is [[miscible]] in water, [[ethanol]], and [[chloroform]], demonstrating its ability to dissolve a wide range of substances including [[ethyl cellulose]], [[polyvinyl butyral]], oils, [[alkaloids]], and natural [[resin]]s. Notably, it is not [[Miscibility|miscible]] with salt solutions and can be separated by adding [[sodium chloride]] in a process known as [[salting out]]. It forms an [[azeotrope]] with water, resulting in a [[boiling point]] of 80.37 °C and is characterized by its slightly bitter taste. Isopropyl alcohol becomes [[viscous]] at lower temperatures, freezing at −89.5 °C, and has significant [[ultraviolet]]-visible absorbance at 205 nm. Chemically, it can be oxidized to [[acetone]] or undergo various reactions to form compounds like isopropoxides or aluminium isopropoxide. As an [[isopropyl]] group linked to a [[hydroxyl]] group ([[chemical formula]] {{chem2|(CH3)2CHOH}}) it is the simplest example of a [[Alcohol (chemistry)#Systematic names|secondary alcohol]], where the [[Alcohol (chemistry)|alcohol]] carbon atom is attached to two other carbon atoms. It is a [[structural isomer]] of [[1-propanol|propan-1-ol]] and [[ethyl methyl ether]]. They all have the formula {{chem2|C3H8O}}.

It was first synthesized in 1853 by [[Alexander William Williamson]] and later produced for [[cordite]] preparation. It is produced through hydration of [[propene]] or [[hydrogenation]] of acetone, with modern processes achieving anhydrous alcohol through [[azeotropic distillation]]. Beyond its production, isopropyl alcohol serves in medical settings as a [[rubbing alcohol]] and [[hand sanitizer]], and in industrial and household applications as a solvent. It is a common ingredient in products such as [[antiseptic]]s, [[disinfectant]]s and [[detergent]]s. More than a million tonnes are produced worldwide annually. Despite its utility, isopropyl alcohol poses safety risks due to its flammability and potential for [[peroxide]] formation. Its ingestion or absorption leads to [[toxic]] effects including [[central nervous system depression]] and [[coma]], primarily treated through supportive measures.

== Properties ==

Isopropyl alcohol is [[miscible]] in water, [[ethanol]], and [[chloroform]], as it is an [[Organic compound|organic]] [[Chemical polarity|polar molecule]]. It dissolves [[ethyl cellulose]], [[polyvinyl butyral]], many oils, alkaloids, and natural resins.<ref Name="Doolittle">{{cite book |last1 = Doolittle |first1 = Arthur K. |title = The Technology of Solvents and Plasticizers |year = 1954 |publisher = John Wiley & Sons, Inc. |location = New York |page = 628 }}</ref> Unlike [[ethanol]] or [[methanol]], isopropyl alcohol is not miscible with salt solutions and can be separated from [[aqueous solution]]s by adding a salt such as [[sodium chloride]]. The process is colloquially called ''[[salting out]]'', and causes concentrated isopropyl alcohol to separate into a distinct layer.<ref name = "Merck">{{cite book |title = The Merck Index | url = https://archive.org/details/merckindexencycl00wind |url-access = registration |edition = 10th |year = 1983 |publisher = Merck & Co. |location = Rahway, NJ |page = [https://archive.org/details/merckindexencycl00wind/page/749 749] | isbn = 9780911910278 }}</ref>

Isopropyl alcohol forms an [[azeotrope]] with water, which gives a boiling point of {{convert|80.37|C|F}} and a composition of 87.7% by mass (91% by volume) isopropyl alcohol.  It has a slightly bitter taste, and is not safe to drink.<ref name = "Merck"/><ref>{{cite book |last1=Logsden |first1=John E. |last2=Loke |first2=Richard A. |editor1-last=Kroschwitz |editor1-first=Jacqueline I. |title=Kirk-Othmer Concise Encyclopedia of Chemical Technology |edition=4th |year=1999 |publisher=John Wiley & Sons, Inc. |location=New York |isbn=978-0-471-41961-7 |pages=1654–1656 |chapter=Propyl Alcohols }}</ref>

Isopropyl alcohol becomes increasingly viscous with decreasing temperature and freezes at {{convert|−89.5|C|F}}.<ref name=PubChem/>  Mixtures with water have higher freezing points: 99% at {{cvt|-89.5|C}}, 91% (the azeotrope) at {{cvt|-75.5|C}}, and 70% at {{cvt|-61.7|C}}.<ref>{{cite web |url=https://voxifyz.com/what-is-the-freezing-point-of-isopropyl-alcohol/ |title=What is the Freezing Point of Isopropyl Alcohol? |date=21 September 2023 |access-date=2023-12-18}}</ref>

Isopropyl alcohol has a maximal [[absorbance]] at 205&nbsp;nm in an [[ultraviolet]]-[[visible spectrum|visible]] spectrum.<ref name="Macron">{{cite web |title = Isopropyl Alcohol, , Suitable for Liquid Chromatography, Extract/, UV-Spectrophotometry |url = https://us.vwr.com/store/catalog/product.jsp?product_id=4583647 |access-date = 25 August 2014 |publisher = [[VWR International]] |archive-date = 31 March 2016 |archive-url = https://web.archive.org/web/20160331144856/https://us.vwr.com/store/catalog/product.jsp?product_id=4583647 |url-status = live }}</ref><ref>{{cite web |title = UV Cutoff |publisher = [[University of Toronto]] |access-date = 25 August 2014 |url = http://www.utsc.utoronto.ca/~traceslab/UV_Cutoff.pdf |archive-date = 8 October 2013 |archive-url = https://web.archive.org/web/20131008035654/http://www.utsc.utoronto.ca/~traceslab/UV_Cutoff.pdf |url-status = live }}</ref>

==Reactions==
Isopropyl alcohol can be [[Organic redox reaction|oxidized]] to [[acetone]], which is the corresponding [[ketone]]. This can be achieved using oxidizing agents such as [[chromic acid]], or by [[dehydrogenation]] of isopropyl alcohol over a heated copper [[catalyst]]:

{{block indent|{{chem2|(CH3)2CHOH -> (CH3)2CO + [[Hydrogen|H2]]}}}}

Isopropyl alcohol is often used as both solvent and [[hydride]] source in the [[Meerwein-Ponndorf-Verley reduction]] and other [[transfer hydrogenation]] reactions. Isopropyl alcohol may be converted to [[2-bromopropane]] using [[phosphorus tribromide]], or dehydrated to [[propene]] by heating with [[sulfuric acid]].

Like most alcohols, isopropyl alcohol reacts with active [[metal]]s such as [[potassium]] to form [[alkoxide]]s that are called '''isopropoxides'''. With [[titanium tetrachloride]], isopropyl alcohol reacts to give [[titanium isopropoxide]]:

{{block indent|{{Chem2|TiCl4  +  4 (CH3)2CHOH  ->  Ti(OCH(CH3)2)4  +  4 HCl}}}}

This and similar reactions are often conducted in the presence of base.

The reaction with [[aluminium]] is initiated by a trace of [[Mercury (element)|mercury]] to give [[aluminium isopropoxide]].<ref name=eEROS>{{cite encyclopedia|last1 = Ishihara|first1 = K.|last2 = Yamamoto|first2 = H.|title = Aluminum Isopropoxide|encyclopedia = [[Encyclopedia of Reagents for Organic Synthesis]]|year = 2001|publisher = [[John Wiley & Sons]]|doi = 10.1002/047084289X.ra084| isbn=0471936235 }}</ref>

== History ==
Isopropyl alcohol was first synthesized by the chemist [[Alexander William Williamson]] in 1853. He achieved this by heating a mixture of propene and sulfuric acid.
[[Standard Oil]] produced isopropyl alcohol by hydrating [[propene]]. Isopropyl alcohol was oxidized to [[acetone]] for the preparation of [[cordite]], a smokeless, [[low explosive]] propellant.<ref>{{cite book |last1 = Wittcoff |first1 = M. M. |last2=Green |first2=H. A. |title = Organic chemistry principles and industrial practice |year = 2003 |publisher = Wiley-VCH |location = Weinheim |isbn = 978-3-527-30289-5 |page = 4 |edition = 1. ed., 1. reprint. }}</ref>

==Production==
In 1994, 1.5 million tonnes of isopropyl alcohol were produced in the United States, Europe, and Japan.<ref name = Ullmann/> It is primarily produced by combining water and [[propene]] in a [[hydration reaction]] or by hydrogenating [[acetone]].<ref name = Ullmann>{{Ullmann | last = Papa |first=A. J. | title = Propanols | doi = 10.1002/14356007.a22_173}}</ref><ref>{{cite encyclopedia |last1=Logsdon |first1=John E. |last2=Loke |first2=Richard A. |title = Kirk-Othmer Encyclopedia of Chemical Technology|encyclopedia = Kirk‑Othmer Encyclopedia of Chemical Technology |publisher = John Wiley & Sons |date = December 4, 2000 |doi=10.1002/0471238961.0919151612150719.a01 |chapter=Isopropyl Alcohol |isbn=978-0471238966 }}</ref> There are two routes for the hydration process and both processes require that the isopropyl alcohol be separated from water and other by-products by [[distillation]]. Isopropyl alcohol and water form an [[azeotrope]], and simple distillation gives a material that is 87.9% by mass isopropyl alcohol and 12.1% by mass water.<ref>''CRC Handbook of Chemistry and Physics'', 44th ed. pp. 2143–2184.</ref> Pure ([[anhydrous]]) isopropyl alcohol is made by [[azeotropic distillation]] of the wet isopropyl alcohol using either [[diisopropyl ether]] or [[cyclohexane]] as azeotroping agents.<ref name = Ullmann/>

===Biological===
Small amounts of isopropyl alcohol are produced in the body in [[diabetic ketoacidosis]].<ref name="PetersenWilliams2012">{{cite journal |last1=Petersen |first1=Thomas H. |last2=Williams |first2=Timothy |last3=Nuwayhid |first3=Naziha |last4=Harruff |first4=Richard |title=Postmortem Detection of Isopropanol in Ketoacidosis |journal=Journal of Forensic Sciences |volume=57 |issue=3 |year=2012 |pages=674–678 |issn=0022-1198 |doi=10.1111/j.1556-4029.2011.02045.x |pmid=22268588|s2cid=21101240}}</ref>

===Indirect hydration===
Indirect [[Hydration reaction|hydration]] reacts propene with [[sulfuric acid]] to form a mixture of sulfate esters. This process can use low-quality propene, and is predominant in the USA. These processes give primarily isopropyl alcohol rather than 1-propanol, because adding water or sulfuric acid to propene follows [[Markovnikov's rule]]. Subsequent [[hydrolysis]] of these esters by steam produces isopropyl alcohol, by distillation. [[Diisopropyl ether]] is a significant by-product of this process; it is recycled back to the process and hydrolyzed to give the desired product.<ref name = Ullmann/>

{{block indent|{{chem2|CH3CH\dCH2 + H2O}} {{overset|{{chem2|H2SO4}}|→}} {{chem2|(CH3)2CHOH}}}}

===Direct hydration===
{{See also|Heteropoly acid}}
Direct hydration reacts propene and water, either in gas or liquid [[Phase (matter)|phase]], at high pressures in the presence of solid or supported acidic [[catalyst]]s. This type of process usually requires higher-purity [[propylene]] (> 90%).<ref name = Ullmann/> Direct hydration is more commonly used in Europe.

===Hydrogenation of acetone===
Isopropyl alcohol can be prepared via the [[hydrogenation]] of [[acetone]], but this approach involves an extra step compared to the above methods, as acetone is itself normally prepared from propene via the [[cumene process]].<ref name = Ullmann/> {{abbr|IPA|Isopropyl alcohol}} cost is primarily driven by raw material cost, and this way is economical when acetone is cheaper than propylene as a [[byproduct]] of [[phenol]] production (the coexistence of two ways on most markets allows them to balance the prices).

A known issue is the formation of [[Methyl isobutyl ketone|MIBK]] and other self-condensation products. [[Raney nickel]] was one of the original industrial catalysts, modern catalysts are often [[Catalyst support|supported]] bimetallic materials.

==Uses==
[[File:One of the small scale uses of isopropanol is in cloud chambers. Isopropanol has ideal physical and chemical properties to form a supersaturated layer of vapor which can be condensed by particles of radiation.jpg|thumb|One of the small scale uses of isopropyl alcohol is in [[cloud chamber]]s. Isopropyl alcohol has ideal physical and chemical properties to form a [[supersaturated]] layer of [[vapor]] which can be [[condensation|condensed]] by [[particles]] of [[radiation]].]]
In 1990, 45,000 metric tonnes of isopropyl alcohol were used in the United States, mostly as a solvent for coatings or for industrial processes. In that year, 5400 metric tonnes were used for household purposes and in personal care products. Isopropyl alcohol is popular in particular for pharmaceutical applications,<ref name = Ullmann/> due to its low toxicity. Some isopropyl alcohol is used as a chemical intermediate. Isopropyl alcohol may be converted to acetone, but the [[cumene process]] is more significant.<ref name = Ullmann/>

===Solvent===
Isopropyl alcohol dissolves a wide range of [[non-polar]] compounds. It evaporates quickly and the typically available grades tend to not leave behind oil traces when used as a cleaning fluid unlike some other common solvents. It is also relatively non-toxic. Thus, it is used widely as a solvent and as a cleaning fluid, especially where there are oils or oil based residues which are not easily cleaned with water, conveniently evaporating and (depending on water content and other variables) posing less of a risk of corrosion or rusting than plain water. Together with [[ethanol]], [[n-Butanol|''n''-butanol]], and [[methanol]], it belongs to the group of alcohol solvents.

Isopropyl alcohol is commonly used for cleaning [[eyeglasses]], [[electrical contact]]s, audio or video [[tape head]]s, DVD and other [[optical disc]] lenses, [[Bong|bongs]],<ref>{{Cite magazine |last=Directo-Meston |first=Danielle |date=2021-02-09 |title=How to Properly Clean Your Bong, According to Cannabis Experts |url=https://www.rollingstone.com/product-recommendations/lifestyle/how-to-clean-a-bong-1121339/ |access-date=2024-03-31 |magazine=Rolling Stone |language=en-US}}</ref> and for removing [[thermal paste]] from [[heatsink]]s on [[CPU]]s<ref>[http://www.arcticsilver.com/pdf/appmeth/int/vl/intel_app_method_vertical_line_v1.1.pdf Intel application method] arcticsilver.com</ref> and other [[Integrated circuit|IC]] packages.

===Intermediate===
Isopropyl alcohol is [[esterified]] to give [[isopropyl acetate]], another solvent. It reacts with [[carbon disulfide]] and [[sodium hydroxide]] to give [[sodium isopropylxanthate]], which has use as an [[herbicide]] and an [[Froth flotation|ore flotation]] reagent.<ref>{{cite web |url = http://www.3dchem.com/moremolecules.asp?ID=318&othername=SIPX |title = Sodium Isopropyl Xanthate, SIPX, Xanthate |publisher = 3DChem.com |access-date = 2012-06-17 |archive-date = 2012-05-04 |archive-url = https://web.archive.org/web/20120504184626/http://3dchem.com/moremolecules.asp?ID=318&othername=SIPX |url-status = live }}</ref> Isopropyl alcohol reacts with [[titanium tetrachloride]] and [[aluminium]] metal to give [[titanium isopropoxide|titanium]] and [[aluminium isopropoxide]]s, respectively, the former a catalyst, and the latter a chemical reagent.<ref name = Ullmann/> This compound may serve as a chemical reagent in itself, by acting as a dihydrogen donor in [[transfer hydrogenation]].

===Medical===
[[Rubbing alcohol]], [[hand sanitizer]], and [[Wet wipe#Healthcare|disinfecting pads]] typically contain a 60–70% [[Solution (chemistry)|solution]] of isopropyl alcohol or [[ethanol]] in [[water (molecule)|water]]. Water is required to open up membrane pores of bacteria, which acts as a gateway for isopropyl alcohol. A 75% {{abbr|v/v|volume per volume}} solution in water may be used as a hand sanitizer.<ref>{{cite web |title = Guide to Local Production: WHO-recommended Handrub Formulations |publisher = World Health Organization |date = August 2009 |url = https://www.who.int/gpsc/5may/Guide_to_Local_Production.pdf |access-date = 2020-10-05 |archive-date = 2009-05-19 |archive-url = https://web.archive.org/web/20090519054112/https://www.who.int/gpsc/5may/Guide_to_Local_Production.pdf |url-status = live }}</ref> Isopropyl alcohol is used as a water-drying aid for the prevention of [[otitis externa]], better known as swimmer's ear.<ref>[https://web.archive.org/web/20100226215757/http://www.mcw.edu/pediatricoto/CommonHealthProblems/OtitisExternaSwimmersEar.htm Otitis Externa (Swimmers Ear)]. Medical College of Wisconsin.</ref>

Inhaled isopropyl alcohol can be used for treating nausea in some settings by placing a disinfecting pad under the nose.<ref>{{Cite journal |last1=Lindblad |first1=Adrienne J. |last2=Ting |first2=Rhonda |last3=Harris |first3=Kevin |date=August 2018 |title=Inhaled isopropyl alcohol for nausea and vomiting in the emergency department |journal=Canadian Family Physician |volume=64 |issue=8 |pages=580 |issn=1715-5258 |pmc=6189884 |pmid=30108075}}</ref>

===Early uses as an anesthetic===
Although isopropyl alcohol can be used for anesthesia, its many negative attributes or drawbacks prohibit this use. Isopropyl alcohol can also be used similarly to ether as a solvent<ref>{{cite journal |doi = 10.1002/jps.3030360105 |title = Pharmaceutical applications of isopropyl alcohol II. Solubilities of local anesthetics |year = 2006 |last1 = Burlage |first1 = Henry M. |journal = Journal of the American Pharmaceutical Association |volume = 36 |pages = 17–19 |pmid = 20285822 |last2 = Welch |first2 = H. |last3 = Price |first3 = C. W. |issue = 1 }}</ref> or as an anesthetic by inhaling the fumes or orally. Early uses included using the solvent as general anesthetic for small mammals<ref>{{cite book |last = Society for Experimental Biology and Medicine |title = Proceedings of the Society for Experimental Biology and Medicine, Volume 19 |year = 1922 |page = 85 |url = https://books.google.com/books?id=5jksAAAAYAAJ |access-date = 2016-09-24 |archive-date = 2021-12-20 |archive-url = https://web.archive.org/web/20211220154854/https://books.google.com/books?id=5jksAAAAYAAJ |url-status = live }}</ref> and rodents by scientists and some veterinarians. However, it was soon discontinued, as many complications arose, including respiratory irritation, internal bleeding, and visual and hearing problems. In rare cases, respiratory failure leading to death in animals was observed.

===Automotive===
Isopropyl alcohol is a major ingredient in "gas dryer" [[fuel additive]]s. In significant quantities, [[water]] is a problem in fuel tanks, as it separates from gasoline and can freeze in the supply lines at low temperatures. Alcohol does not remove water from gasoline, but the alcohol [[Micellar solubilization|solubilizes]] water in gasoline. Once [[soluble]], water does not pose the same risk as insoluble water, as it no longer accumulates in the supply lines and freezes but is dissolved within the fuel itself. Isopropyl alcohol is often sold in aerosol cans as a [[windshield]] or door lock deicer. Isopropyl alcohol is also used to remove [[brake fluid]] traces from hydraulic braking systems, so that the brake fluid (usually [[DOT 3]], [[DOT 4]], or [[mineral oil]]) does not contaminate the [[brake pads]] and cause poor braking. Mixtures of isopropyl alcohol and water are also commonly used in homemade windshield washer fluid.

===Laboratory===
As a biological specimen preservative, isopropyl alcohol provides a comparatively non-toxic alternative to [[formaldehyde]] and other synthetic preservatives. Isopropyl alcohol solutions of 70–99% are used to preserve specimens.

Isopropyl alcohol is often used in [[DNA extraction]]. A lab worker adds it to a DNA solution to precipitate the DNA, which then forms a pellet after centrifugation. This is possible because DNA is insoluble in isopropyl alcohol.

=== Semiconductors ===
Isopropyl alcohol is used as an additive in alkaline [[Anisotropy#Microfabrication|anisotropic etching]] of [[monocrystalline silicon]], such as with [[potassium hydroxide]] or [[tetramethylammonium hydroxide]]. This process is used in texturing of [[Solar cell|silicon solar cells]] and microfabrication (e.g. in [[MEMS]] devices). Isopropyl alcohol increases the anisotropy of the etch by increasing the etch rate of [100] plane relative to [[Miller index|higher indexed planes]].<ref>{{Cite journal |last1=Zubel |first1=Irena |last2=Kramkowska |first2=Małgorzata |date=2002-10-30 |title=The effect of alcohol additives on etching characteristics in KOH solutions |url=https://www.sciencedirect.com/science/article/pii/S0924424702002650 |journal=Sensors and Actuators A: Physical |language=en |volume=101 |issue=3 |pages=255–261 |doi=10.1016/S0924-4247(02)00265-0 |issn=0924-4247}}</ref>

==Safety==
Isopropyl alcohol vapor is denser than air and is [[flammable]], with a [[flammability limit|flammability range]] of between 2% and 12.7% in air. It should be kept away from heat, sparks, and open flame.<ref name = Sigma>{{cite web |url = http://www.sigmaaldrich.com/MSDS/MSDS/DisplayMSDSPage.do?country=US&language=en&productNumber=W292907&brand=ALDRICH |title = Isopropanol |date = 19 January 2012 |publisher = Sigma-Aldrich |access-date = 6 July 2012 |archive-date = 17 January 2021 |archive-url = https://web.archive.org/web/20210117225116/http://www.sigmaaldrich.com/MSDS/MSDS/DisplayMSDSPage.do?country=US&language=en&productNumber=W292907&brand=ALDRICH |url-status = live }}</ref> Distillation of isopropyl alcohol over magnesium has been reported to form [[organic peroxide|peroxides]], which may explode upon concentration.<ref>{{Cite journal |doi = 10.1021/ed065pA226 |title = Control of peroxidizable compounds: An addendum |journal = Journal of Chemical Education |volume = 65 |issue = 9 |pages = A226 |year = 1988 |last1 = Mirafzal |first1 = Gholam A. |last2 = Baumgarten |first2 = Henry E. |bibcode = 1988JChEd..65A.226M}}</ref><ref>{{cite journal | url = https://cen.acs.org/articles/94/i31/Chemical-safety-peroxide-formation-isopropanol.html | title = Chemical safety: peroxide formation in 2-propanol | journal = [[Chemical & Engineering News]] | volume = 94 | issue = 31 | page = 2 | date = August 1, 2016 | access-date = November 2, 2017 | archive-date = November 7, 2017 | archive-url = https://web.archive.org/web/20171107024355/https://cen.acs.org/articles/94/i31/Chemical-safety-peroxide-formation-isopropanol.html | url-status = live }}</ref> Isopropyl alcohol can react with air and oxygen over time to form unstable peroxides that can explode.<ref>{{cite web |title=Hazardous Substance Fact Sheet |url=https://nj.gov/health/eoh/rtkweb/documents/fs/1076.pdf |website=Official Site of The State of New Jersey |access-date=4 November 2023}}</ref>

==Toxicology==
Isopropyl alcohol, via its metabolites, is somewhat more toxic than ethanol, but considerably less toxic than [[ethylene glycol]] or [[methanol]]. Death from ingestion or absorption of even relatively large quantities is rare. Both isopropyl alcohol and its [[metabolite]], [[acetone]], act as [[central nervous system]] (CNS) [[depressant]]s.<ref name="pmid24815348">{{cite journal |vauthors = Slaughter RJ, Mason RW, Beasley DM, Vale JA, Schep LJ |title = Isopropanol poisoning |journal = [[Clinical Toxicology]] |volume = 52 |issue = 5 |pages = 470–8 |year = 2014 |pmid = 24815348 |doi = 10.3109/15563650.2014.914527 |s2cid = 30223646 }}</ref> Poisoning can occur from ingestion, inhalation, or skin absorption.<ref>{{Cite journal |last1=Chavez |first1=Andrew R. |last2=Sweeney |first2=Michael |last3=Akpunonu |first3=Peter |date=2021-12-14 |title=A Case of Unintentional Isopropanol Poisoning via Transdermal Absorption Delayed by Weekly Hemodialysis |journal=The American Journal of Case Reports |volume=22 |pages=e934529 |doi=10.12659/AJCR.934529 |issn=1941-5923 |pmc=8689373 |pmid=34905533}}</ref> [[Symptom]]s of isopropyl alcohol poisoning include [[flushing (physiology)|flushing]], [[headache]], [[dizziness]], [[Central nervous system depression|CNS depression]], [[nausea]], [[vomiting]], [[anesthesia]], [[hypothermia]], [[hypotension|low blood pressure]], [[Shock (circulatory)|shock]], [[Hypoventilation|respiratory depression]], and [[coma]].<ref name="pmid24815348"/> Overdoses may cause a fruity odor on the breath as a result of its metabolism to [[acetone]].<ref>{{cite journal |last1 = Kalapos |first1 = M. P. |title = On the mammalian acetone metabolism: from chemistry to clinical implications |journal = Biochimica et Biophysica Acta (BBA) - General Subjects |volume = 1621 |issue = 2 |pages = 122–39 |year = 2003 |pmid = 12726989 |doi = 10.1016/S0304-4165(03)00051-5 }}</ref>
Isopropyl alcohol does not cause an [[anion gap acidosis]], but it produces an [[Serum osmolal gap|osmolal gap]] between the calculated and measured osmolalities of serum, as do the other alcohols.<ref name="pmid24815348"/> The findings of [[acetone]] without acidosis leads to the [[sine qua non]] of "ketosis without acidosis."

Isopropyl alcohol is oxidized to form acetone by [[alcohol dehydrogenase]] in the liver<ref name="pmid24815348"/> and has a [[biological half-life]] in humans between 2.5 and 8.0 hours.<ref name="pmid24815348"/> Unlike [[methanol]] or [[ethylene glycol]] poisoning, the metabolites of isopropyl alcohol are considerably less toxic, and treatment is largely supportive. Furthermore, there is no indication for the use of [[fomepizole]], an alcohol dehydrogenase inhibitor, unless co-ingestion with methanol or ethylene glycol is suspected.<ref>{{Cite web |url=https://www.uptodate.com/contents/isopropyl-alcohol-poisoning#H15 |title=Isopropyl alcohol poisoning |website=uptodate.com |access-date=2017-10-10 |archive-date=2017-10-10 |archive-url=https://web.archive.org/web/20171010212139/https://www.uptodate.com/contents/isopropyl-alcohol-poisoning#H15 |url-status=live }}</ref>

In [[forensic pathology]], people who have died as a result of [[diabetic ketoacidosis]] or [[Alcoholic ketoacidosis|alcoholic ketoacidosis]], with no isopropyl alcohol ingestion, usually have detectable blood concentrations of isopropyl alcohol of 1 to 40 mg/dL, while those by fatal isopropyl alcohol ingestion usually have blood concentrations of hundreds of mg/dL.<ref name="PetersenWilliams2012"/>

==References==
{{reflist|35em}}

==External links==
* [https://www.cdc.gov/niosh/npg/npgd0359.html CDC – NIOSH Pocket Guide to Chemical Hazards - Isopropyl alcohol]
* [[Environmental Health Criteria]] 103: [http://www.inchem.org/documents/ehc/ehc/ehc103.htm 2-Propanol]

{{Alcohols}}
{{Chemical agents}}
{{Antiseptics and disinfectants}}
{{GABAAR PAMs}}

[[Category:Alcohol solvents]]
[[Category:Oxygenates]]
[[Category:Antiseptics]]
[[Category:Disinfectants]]
[[Category:Secondary alcohols]]
[[Category:GABAA receptor positive allosteric modulators]]
[[Category:Alkanols]]
[[Category:Isopropyl compounds]]
[[Category:Household chemicals]]
[[Category:Nerve agent precursors]]