Browse history interactively

Page 1

Page 1Revision 1

Page 2

Page 2Revision 2

← Previous editContent deleted Content addedVisualWikitext

Revision as of 09:05, 9 August 2011 editBeetstra (talk | contribs)Edit filter managers, Administrators172,031 edits Script assisted update of identifiers for the Chem/Drugbox validation project (updated: 'DrugBank', 'ChEBI').← Previous edit		Latest revision as of 06:10, 4 December 2024 edit undo103.102.87.158 (talk) →Synthetic glycerol
(980 intermediate revisions by more than 100 users not shown)
Line 1:		Line 1:
	{{Redirect4|Glycerine|Glycerin|the Bush song|]}}		{{short description|Chemical compound widely used in food and pharmaceuticals}}{{Redirect|Glycerine|the song by Bush|Glycerine (song)}}{{Use dmy dates|date=August 2024}}
	{{chembox		{{Chembox
	| Watchedfields = changed		| Watchedfields = changed
	| verifiedrevid = 407832953		| verifiedrevid = 464392960
	| Name = Glycerol		| Name = Glycerol
	| ImageFile1 = Glycerin_Skelett.svg		| ImageFile1 = Glycerin_Skelett.svg
			| ImageName1 = Glycerol
	| ImageSize1 =
			| ImageClass1 = skin-invert-image
	| ImageName1 = Glycerol
	| ImageFile2 = Glycerol-3D-balls.png		| ImageFileL2 = Glycerol-3D-balls.png
			| ImageNameL2 = Ball-and-stick model of glycerol
	| ImageSize2 =
			| ImageFileR2 = Glycerol-3D-vdW.png
	| ImageName2 = Ball-and-stick model of glycerol
			| ImageNameR2 = Space-filling model of glycerol
	| ImageFile3 = Glycerol-3D-vdW.png
			| ImageFile3 = Sample of Glycerine.jpg
	| ImageSize3 = 180
	| ImageName3 = Space-filling model of glycerol		| ImageName3 = Sample of glycerine
			| PIN = Propane-1,2,3-triol<ref>{{cite book |author=] |date=2014 |title=Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013 |publisher=] |pages=690 |doi=10.1039/9781849733069 |isbn=978-0-85404-182-4}}</ref>
	| IUPACName = propan-1,2,3-triol
			| OtherNames = {{Unbulleted list
	| OtherNames = glycerin<br /> glycerine<br /> propane-1,2,3-triol<br /> 1,2,3-propanetriol<br /> 1,2,3-triglycerol<br /> 1,2,3-trihydroxypropane<br /> glyceritol<br /> glycyl alcohol
			| 1,2,3-Trioxypropane
	| Section1 = {{Chembox Identifiers
			| 1,2,3-Trihydroxypropane
	| UNII_Ref = {{fdacite|correct|FDA}}
			| 1,2,3-Propanetriol
	| UNII = PDC6A3C0OX
	| KEGG_Ref = {{keggcite|correct|kegg}}
	| KEGG = D00028
	| InChI = 1/C3H8O3/c4-1-3(6)2-5/h3-6H,1-2H2
	| InChIKey = PEDCQBHIVMGVHV-UHFFFAOYAF
	| ChEMBL_Ref = {{ebicite|correct|EBI}}
	| ChEMBL = 692
	| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
	| StdInChI = 1S/C3H8O3/c4-1-3(6)2-5/h3-6H,1-2H2
	| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
	| StdInChIKey = PEDCQBHIVMGVHV-UHFFFAOYSA-N
	| CASNo_Ref = {{cascite|correct|CAS}}
	| CASNo = 56-81-5
	| PubChem = 753
	| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
	| ChemSpiderID = 733
	| ATCCode_prefix = A06
	| ATCCode_suffix = AG04
	| ATC_Supplemental = {{ATC|A06|AX01}}, {{ATCvet|A16|QA03}}
	| DrugBank = DB04077
	| ChEBI = 17522
	| SMILES = C(C(CO)O)O
	}}
	| Section2 = {{Chembox Properties
	| C = 3
	| H = 8
	| O = 3
	| Appearance = clear, colorless liquid <br /> ]
	| Odour = odorless
	| Density = 1.261 g/cm<sup>3</sup>
	| Viscosity = 1.412 Pa&middot;s<ref name="Viscosity of Glycerol and its Aqueous Solutions">{{Cite web|url=http://pubs.acs.org/doi/pdf/10.1021/ie50501a040/|title=Viscosity of Glycerol and its Aqueous Solutions|accessdate=2011-04-19}}</ref>
	| MeltingPt = 17.8 °C, 291.0 K, 64.0 °F
	| BoilingPt = 290 °C, 563 K, 554°F <ref>Lide, D. R., Ed. ''CRC Handbook of Data on Organic Compounds'', 3rd ed.; CRC Press: Boca Raton, FL, 1994; p 4386.</ref>
	| RefractIndex = 1.4746
	}}		}}
	| Section7 = {{Chembox Hazards		| Section1 = {{Chembox Identifiers
			|IUPHAR_ligand = 5195
	| ExternalMSDS =
			|UNII_Ref = {{fdacite|correct|FDA}}
	| NFPA-H = 1
			|UNII = PDC6A3C0OX
	| NFPA-F = 1
			|KEGG_Ref = {{keggcite|correct|kegg}}
	| NFPA-R = 0
			|KEGG = D00028
	| NFPA-O =
			|InChI = 1/C3H8O3/c4-1-3(6)2-5/h3-6H,1-2H2
	| FlashPt = 160 °C (closed cup) <br /> 176 °C (open cup)
			|InChIKey = PEDCQBHIVMGVHV-UHFFFAOYAF
			|ChEMBL_Ref = {{ebicite|correct|EBI}}
			|ChEMBL = 692
			|StdInChI_Ref = {{stdinchicite|correct|chemspider}}
			|StdInChI = 1S/C3H8O3/c4-1-3(6)2-5/h3-6H,1-2H2
			|StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
			|StdInChIKey = PEDCQBHIVMGVHV-UHFFFAOYSA-N
			|CASNo_Ref = {{cascite|correct|CAS}}
			|CASNo = 56-81-5
			|PubChem = 753
			|ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
			|ChemSpiderID = 733
			|DrugBank_Ref = {{drugbankcite|correct|drugbank}}
			|DrugBank = DB04077
			|ChEBI = 17754
			|ChEBI_Ref = {{ebicite|correct|EBI}}
			|SMILES = OCC(O)CO
			}}
			| Section2 = {{Chembox Properties
			|C=3 | H=8 | O=3
			|Appearance = Colorless ] liquid
			|Odor = Odorless
			|Density = 1.261 g/cm<sup>3</sup>
			|Viscosity = 1.412 Pa·s (20&nbsp;°C)<ref name="Viscosity of Glycerol and its Aqueous Solutions">{{cite journal |last1= Segur |first1= J. B. |last2= Oberstar |first2= H. E. |doi= 10.1021/ie50501a040 |title= Viscosity of Glycerol and Its Aqueous Solutions |journal= Industrial & Engineering Chemistry |volume= 43 |issue= 9 |pages= 2117–2120 |year= 1951 }}</ref>
			|MeltingPtC = 17.8
			|BoilingPtC = 290
			|BoilingPt_ref = <ref>{{cite book |editor= Lide, D. R. |title= CRC Handbook of Data on Organic Compounds |edition= 3rd |publisher= CRC Press |location= Boca Raton, FL |year= 1994 |page= 4386}}</ref>
			|RefractIndex = 1.4746
			|VaporPressure = {{cvt|0.003|mmHg|Pa}} at 50&nbsp;°C<ref name=PGCH/>
			|Solubility = miscible<ref name=PGCH/>
			|MagSus = {{val|-57.06e-6|u=cm<sup>3</sup>/mol}}
			|LogP = −2.32<ref name="chemsrc">{{Cite web|url=https://www.chemsrc.com/en/cas/56-81-5_401679.html|title=glycerin_msds|access-date=7 May 2018|archive-date=8 March 2020|archive-url=https://web.archive.org/web/20200308030040/https://www.chemsrc.com/en/cas/56-81-5_401679.html|url-status=live}}</ref>
			}}
			| Section3 = {{Chembox Pharmacology
			|ATCCode_prefix = A06
			|ATCCode_suffix = AG04
			|ATC_Supplemental = {{ATC|A06|AX01}}, {{ATCvet|A16|QA03}}
			}}
			| Section4 = {{Chembox Hazards
			|ExternalSDS =
			|NFPA-H = 1
			|NFPA-F = 1
			|NFPA-R = 0
			|FlashPt = {{convert|160|C|F K}} (closed cup)<br /> {{convert|176|C|F K}} (open cup)
			|PEL = TWA 15&nbsp;mg/m<sup>3</sup> (total)<br /> TWA 5&nbsp;mg/m<sup>3</sup> (resp)<ref name=PGCH>{{PGCH|0302}}</ref>
			|IDLH = N.D.<ref name=PGCH/>
			|REL = None established<ref name=PGCH/>
	}}		}}
	}}		}}
			'''Glycerol''' ({{IPAc-en|ˈ|g|l|ɪ|s|ə|r|ɒ|l}})<ref>{{cite web|url=https://www.oxforddictionaries.com/definition/english/glycerol|title=glycerol – Definition of glycerol in English by Oxford Dictionaries|website=Oxford Dictionaries – English|access-date=21 February 2022|archive-date=21 June 2016|archive-url=https://web.archive.org/web/20160621205507/http://www.oxforddictionaries.com/definition/english/glycerol|url-status=dead}}</ref> is a simple ] compound. It is a colorless, odorless, ] liquid that is sweet-tasting and non-toxic. The glycerol backbone is found in ]s known as ]s. It is also widely used as a sweetener in the food industry and as a ] in ]s. Because of its three ]s, glycerol is ] with ] and is ] in nature.<ref name="Ullmann"/>
	'''Glycerol''' (or '''glycerin''', '''glycerine''') is a simple ] compound. It is a colorless, odorless, ] liquid that is widely used in ]s. Glycerol has three ] ]s that are responsible for its ] in ] and its ] nature. The glycerol backbone is central to all ]s known as ]. Glycerol is sweet-tasting and of low ]. The term '''polyglycerol''' refers to many glycerol molecules together.
			Modern use of the word '''glycerine''' (alternatively spelled '''glycerin''') refers to commercial preparations of less than 100% purity, typically 95% glycerol. <ref>{{cite web|url= https://www.echemi.com/cms/1795050.html |title=Is There any Difference Between Glycerin and Glycerol?|website=Oxford Dictionaries – English|date=9 April 2024|access-date=20 October 2024}}</ref>
	==Production==
	Glycerol forms the backbone of ]s, and can be produced by ] of fats, e.g. a byproduct of ]. Saponification is also referred to as the hydrolysis of esters in basic solutions or environments. The ] of this reaction involves a very rapid equilibrium where the alkoxide functions as a base deprotonating the carboxylic acid (an acidic work up would allow the carboxylic acid to be obtained from the reaction).
			==Structure==
	:]
			Although ], glycerol is ] with respect to reactions of one of the two primary alcohols. Thus, in substituted derivatives, the ] labels the molecule with a ''sn''- prefix before the stem name of the molecule.<ref>{{cite journal |last=Hirschmann|first=H.|date=1960-10-01|title=The Nature of Substrate Asymmetry in Stereoselective Reactions|journal=Journal of Biological Chemistry|volume=235|issue=10|pages=2762–2767|doi=10.1016/S0021-9258(18)64537-5|pmid=13714619|doi-access=free}}</ref><ref>{{cite journal |date=1967-09-01|title=IUPAC-IUB Commission on Biochemical Nomenclature (CBN)|journal=European Journal of Biochemistry|volume=2|issue=2|pages=127–131|doi=10.1111/j.1432-1033.1967.tb00116.x|pmid=6078528|doi-access=}}</ref><ref name="pmid29301208">{{cite journal | vauthors=Alfieri A, Imperlini E, Nigro E, Vitucci D, Orrù S, Daniele A, Buono P, Mancini A | title=Effects of Plant Oil Interesterified Triacylglycerols on Lipemia and Human Health | journal= ] | volume=19 | issue=1 | pages=E104 | year=2017 | doi= 10.3390/ijms19010104 | pmc =5796054 | pmid = 29301208 | doi-access=free}}</ref>
			==Production==
	It also is a byproduct of the production of ] via ]. This form of crude glycerin is often dark in appearance with a thick, syrup-like consistency. Triglycerides ('''1''') are reacted with an alcohol such as ethanol ('''2''') with catalytic base to give ethyl esters of fatty acids ('''3''') and glycerol ('''4'''):
			Glycerol is generally obtained from plant and animal sources where it occurs in ]s, ]s of glycerol with long-chain ]. The ], ], or ] of these triglycerides produces glycerol as well as the fatty acid derivative:
			<div style="display: flex; max-width: 100%; overflow-x: auto">
			{{Biochem reaction subunit |compound=Triglyceride |image=Fat_structural_formulae_V3.svg |imagesize=150px}}
			{{Biochem reaction subunit |direction=forward |title=3 ] / {{H2O-nl}} |title_lower={{abbr|Δ|heating}}}}
			{{Biochem reaction subunit |n=3 |compound=soap |image=General sodium carboxylate.svg}}
			{{Biochem reaction subunit |compound=glycerol |image=Glycerine Structural Formula V1.svg}}
			</div>
			Triglycerides can be saponified with ] to give glycerol and fatty sodium salt or ].
			Typical plant sources include ] or ]. Animal-derived ] is another source. Approximately 950,000 tons per year are produced in the United States and Europe; 350,000 tons of glycerol were produced per year in the U.S. alone from 2000 to 2004.<ref>{{cite web |title= A Glycerin Factor |author= Nilles, Dave |url= https://www.biodieselmagazine.com/article.jsp?article_id=377 |publisher= Biodiesel Magazine |year= 2005 |access-date= 21 February 2022 |archive-date= 8 November 2007 |archive-url= https://web.archive.org/web/20071108114027/http://www.biodieselmagazine.com/article.jsp?article_id=377 |url-status= live }}</ref> The ] set a requirement that 5.75% of petroleum fuels were to be replaced with ] sources across all ] by 2010. It was projected in 2006 that by 2020, production would be six times more than demand, creating an excess of glycerol as a byproduct of biofuel production.<ref name="Ullmann">{{cite encyclopedia |encyclopedia= Ullmann's Encyclopedia of Industrial Chemistry |last1= Christoph |first1= Ralf |last2= Schmidt |first2= Bernd |last3= Steinberner |first3= Udo |last4= Dilla |first4= Wolfgang |last5= Karinen |first5= Reetta |year= 2006 |doi= 10.1002/14356007.a12_477.pub2 |chapter= Glycerol |isbn= 3527306730}}</ref>
	:]
			Glycerol from triglycerides is produced on a large scale, but the crude product is of variable quality, with a low selling price of as low as US$0.02–0.05 per kilogram in 2011.<ref>{{cite journal |last1 = San Kong |first1 = Pei |last2 = Kheireddine Aroua |first2 = Mohamed |last3 = Ashri Wan Daud |first3 = Wan Mohd |year = 2016 |title = Conversion of crude and pure glycerol into derivatives: A feasibility evaluation |journal = Renewable and Sustainable Energy Reviews |volume = 63 |pages = 533–555 |doi = 10.1016/j.rser.2016.05.054 |bibcode = 2016RSERv..63..533K }}</ref> It can be purified, but the process is expensive. Some glycerol is burned for energy, but its heat value is low.<ref>{{cite news |url= https://www.biodieselmagazine.com/articles/8137/clearing-the-way-for-byproduct-quality |work= Biodiesel Magazine |title= Clearing the way for byproduct quality: why quality for glycerin is just as important for biodiesel |author= Sims, Bryan |date= 25 October 2011 |access-date= 21 February 2022 |archive-date= 29 April 2021 |archive-url= https://web.archive.org/web/20210429154729/http://www.biodieselmagazine.com/articles/8137/clearing-the-way-for-byproduct-quality |url-status= live}}</ref>
	Glycerol is also produced by various routes from ]. The ] process is the most important; it involves the chlorination of propylene to give ], which is oxidized with ] to ]s, which reacts with a strong base to give ]. ] is then hydrolyzed to give glycerol.<ref name="Ullmann" />
			Crude glycerol from the hydrolysis of triglycerides can be purified by treatment with ] to remove organic impurities, alkali to remove unreacted glycerol esters, and ] to remove salts. High purity glycerol (greater than 99.5%) is obtained by multi-step distillation; a ] is necessary due to its high boiling point (290&nbsp;°C).<ref name=Ullmann/>
	Because of the emphasis on ], where glycerol is a waste product, the market for glycerol is depressed, and the old ] process for glycerol synthesis is no longer economical on a large scale. Glycerol can be removed from the process by using a special enzyme that breaks down phytol and starches. This enzyme is biologically produced using a genetically engineered bacterium. Because there is no glycerin produced as a by-product, the biodiesel purity is greatly improved and costs can be reduced. <ref>{{cite web|title=Biosynthesis of Biodiesel without Glycerin By-Product|url=http://www.license.umn.edu/Products/Biosynthesis-of-Biodiesel-without-Glycerin-By-Product__Z07163.aspx|publisher=University of Minnesota|accessdate=27 May 2011}}</ref>
			===Synthetic glycerol===
	Only one producer for synthetic glycerol is left, because high-quality glycerol is needed in highly sensitive pharmaceutical, technical and personal care applications. Raw materials used to make glycerol and glycerin include animal fats, such as beef tallow, and vegetable oils, such as coconut and soybean.<ref></ref> Approximately 950,000 tons per annum are produced in the USA and Europe; 350,000 tons of glycerol were produced per year in the United States alone from 2000-2004.<ref>{{cite web | title = A Glycerin Factor | author = Dave Nilles | url = http://www.biodieselmagazine.com/article.jsp?article_id=377 | publisher = Biodiesel Magazine | year = 2005}}</ref> Production will increase as the ] is implemented, which requires the replacement of 5.75% of petroleum fuels with ] across all Member States by 2010. It is projected that by the year 2020, production will be six times more than demand.<ref name="Ullmann">{{cite encyclopedia | encyclopedia = Ullmann's Encyclopedia of Industrial Chemistry | last1 = Christoph | first1 = Ralf | last2 = Schmidt | first2 = Bernd | last3 = Steinberner | first3 = Udo | last4 = Dilla | first4 = Wolfgang | last5 = Karinen | first5 = Reetta | title = Glycerol | year = 2006 | doi = 10.1002/14356007.a12_477.pub2 }}</ref>
			Because of the large-scale production of ] from fats, where glycerol is a waste product, the market for glycerol is depressed. Thus, synthetic processes are not ]. Owing to oversupply, efforts are being made to convert glycerol to synthetic precursors, such as ] and epichlorohydrin.<ref>{{cite journal |title= Glycerol|last= Yu|first= Bin|journal= Synlett|volume= 25|issue= 4|pages= 601–602|doi= 10.1055/s-0033-1340636|year= 2014|doi-access= free}}</ref>
			Although usually not cost-effective because so much is produced from processing of fats, glycerol can be produced by various routes. During ], synthetic glycerol processes became a national defense priority because it is a precursor to ]. Epichlorohydrin is the most important precursor. ] of propylene gives ], which is oxidized with ] to ], which reacts with a strong base to give ]. Epichlorohydrin can be hydrolyzed to glycerol. ]-free processes from propylene include the synthesis of glycerol from ] and ].<ref name="Ullmann" />
	==Applications==
			: ]
	{{Ref improve section|date=March 2009}}
			==Applications==
	===Food industry===		===Food industry===
	In foods and beverages, glycerol serves as a ], ], and ], and may help ]. It is also used as filler in commercially prepared ] foods (e.g., ]s), and as a ] in ]s. Glycerol and water are used to preserve certain types of leaves. As a ], it has approximately 27 ] per ] (sugar has 20) and is 60% as ] as ]. Although it has about the same ] as ], it does not raise ] levels, nor does it feed the ] that form ]s and cause ]. As a ], glycerol is labeled as ] E422.		In food and beverages, glycerol serves as a ], ], and ], and may help ]. It is also used as filler in commercially prepared ] foods (e.g., ]s), and as a ] in ]s. Glycerol and water are used to preserve certain types of plant leaves.<ref>{{cite journal |url= https://extension.umd.edu//sites/extension.umd.edu/files/_images/programs/hgic/Publications/non_HGIC_FS/FS556.pdf |title= Preserving flowers and leaves |last= Gouin |first= Francis R. |year= 1994 |journal= Maryland Cooperative Extension Fact Sheet |volume= 556 |pages= 1–6 |access-date= 20 January 2018 |archive-date= 21 January 2018 |archive-url= https://web.archive.org/web/20180121072119/https://extension.umd.edu//sites/extension.umd.edu/files/_images/programs/hgic/Publications/non_HGIC_FS/FS556.pdf |url-status= live }}</ref><!--<ref>{{cite web |title= Preserving flowers and decorative foliages with glycerin and dye |author= Stevens, Alan |url= https://www.ksre.ksu.edu/library/hort2/mf2446.pdf }}{{dead link |date=October 2017 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>--> As a ], it has approximately 27 ] per ] (sugar has 20) and is 60% as ] as ]. It does not feed the ] that form a ] and cause ].{{citation needed |date=October 2016}} As a ], glycerol is labeled as ] E422. It is added to ] (frosting) to prevent it from setting too hard.
			As used in foods, glycerol is categorized by the U.S. ] as a ]. The U.S. ] (FDA) carbohydrate designation includes all caloric ]s excluding protein and fat. Glycerol has a caloric density similar to table sugar, but a lower ] and different ] within the body.
	Glycerol is also used to manufacture mono- and di-]s for use as ]s, as well as polyglycerol ]s going into ]s and ].
			It is also recommended as an additive when using polyol sweeteners such as ] and ] which have a cooling effect, due to its heating effect in the mouth, if the cooling effect is not wanted.<ref>{{cite web |title= Functional Food Design Rules |author= Nikolov, Ivan |date= 20 April 2014 |url= https://www.ivannikolov.com/functional-food-design-rules-part-2/ |access-date= 21 February 2022 |archive-date= 30 April 2021 |archive-url= https://web.archive.org/web/20210430030741/https://ivannikolov.com/functional-food-design-rules-part-2/ |url-status= live }}</ref>
	It is also used as a ] (along with ] labelled as E1520 and/or E422) in the production of ], a Swedish-style ] product.
			===Medical, pharmaceutical and personal care applications===
	As used in foods, glycerol is categorized by the ] as a ]. The U.S. ] (FDA) carbohydrate designation includes all caloric ]s excluding protein and fat. Glycerin has a caloric density similar to table sugar, but a lower ] and different ] within the body, so some dietary advocates accept glycerin as a sweetener compatible with ]s.<!-- cribbing wildly from the original nonsense, with extensive rant on talk page -->
			]
			]
			]
			]
			Glycerol is used in ], ] and ] preparations, often as a means of improving smoothness, providing ], and as a ].
	===Pharmaceutical and personal care applications===
	Glycerol is used in ] and ] and ] preparations, mainly as a means of improving smoothness, providing ] and as a ]. It is found in allergen immunotherapies, ]s, elixirs and ]s, ], ]es, ] products, shaving cream, ] products, ]s and water-based ]s. In solid dosage forms like tablets, glycerol is used as a tablet holding agent. For human consumption, glycerol is classified by the U.S. FDA among the ]s as a caloric macronutrient.		] and ] have been relieved by the topical use of glycerin.<ref>{{cite book|title=Ichthyosis: New Insights for the Healthcare Professional|date=22 July 2013|publisher=]|language=en|isbn=9781481659666|page=22}}</ref><ref name="LebwohlHeymann2017">{{cite book|title=Treatment of Skin Disease E-Book: Comprehensive Therapeutic Strategies|date=19 September 2017|publisher=Elsevier Health Sciences|language=en|isbn=9780702069130 |author=Mark G. Lebwohl |author2=Warren R. Heymann |author3=John Berth-Jones |author4=Ian Coulson}}</ref> It is found in allergen ], ]s, ]s and ]s, ], ]es, ] products, shaving cream, ] products, ]s, and water-based ]s. In solid dosage forms like tablets, glycerol is used as a tablet holding agent. For human consumption, glycerol is classified by the FDA among the ]s as a caloric macronutrient. Glycerol is also used in ] to preserve ]s prior to freezing.{{cn|date=April 2024}}
			Taken rectally, glycerol functions as a ] by irritating the anal mucosa and inducing a ],<ref>{{cite web |url= https://www.drugs.com/cdi/glycerin-enema.html |title= Glycerin Enema |publisher= Drugs.com |access-date= 17 November 2012 |archive-date= 6 November 2012 |archive-url= https://web.archive.org/web/20121106235146/http://www.drugs.com/cdi/glycerin-enema.html |url-status= live }}</ref> expanding the ] by drawing water into it to induce ] resulting in ].<ref>{{cite web |url=https://www.cancer.gov/publications/dictionaries/cancer-drug/def/glycerin-enema |title=glycerin enema |work=NCI Drug Dictionary |publisher=] |access-date=2019-05-02 |date=2 February 2011 |archive-date=2 May 2019 |archive-url=https://web.archive.org/web/20190502220442/https://www.cancer.gov/publications/dictionaries/cancer-drug/def/glycerin-enema |url-status=live }}</ref> It may be administered undiluted either as a ] or as a small-volume (2–10&nbsp;ml) ]. Alternatively, it may be administered in a dilute solution, such as 5%, as a high-volume enema.<ref>{{Citation |author=E. Bertani |author2=A. Chiappa |author3=R. Biffi |author4=P. P. Bianchi |author5=D. Radice |author6=V. Branchi |author7=S. Spampatti |author8=I. Vetrano |author9=B. Andreoni | title = Comparison of oral polyethylene glycol plus a large volume glycerine enema with a large volume glycerine enema alone in patients undergoing colorectal surgery for malignancy: a randomized clinical trial | journal = Colorectal Disease | volume = 13 | issue = 10 | pages = e327–e334 | year = 2011 | pmid = 21689356 | doi = 10.1111/j.1463-1318.2011.02689.x | s2cid = 32872781}}</ref>
	Glycerol is always a component of ], which is made from ], glycerol, sodium castorate (from ]), ], ], ], and water. Sometimes one adds ], or ] for ]. This kind of soap is used by people with sensitive, easily-irritated ] because it prevents skin dryness with its ] properties. It draws moisture up through skin layers and slows or prevents excessive drying and evaporation. It is possible to make glycerol soap at home.
			Taken orally (often mixed with fruit juice to reduce its sweet taste), glycerol can cause a rapid, temporary decrease in the ]. This can be useful for the initial emergency treatment of severely elevated eye pressure.<ref>{{cite web |url= https://www.mayoclinic.com/health/drug-information/DR601713 |title= Glycerin (Oral Route) |publisher= Mayo Foundation for Medical Education and Research |access-date= 17 November 2012 |archive-date= 27 November 2012 |archive-url= https://web.archive.org/web/20121127150445/http://www.mayoclinic.com/health/drug-information/DR601713 |url-status= live }}</ref>
	Used as a ] when introduced into the rectum in ] or small-volume (2–10&nbsp;ml)(]) form; irritates the anal mucosa and induces a ].
			In 2017, researchers showed that the probiotic '']'' bacteria can be supplemented with glycerol to enhance its production of antimicrobial substances in the human gut. This was confirmed to be as effective as the antibiotic ] at inhibiting '']'' infection without having a significant effect on the overall microbial composition of the gut.<ref>{{Cite journal |last1=Spinler |first1=Jennifer K. |last2=Auchtung |first2=Jennifer |last3=Brown |first3=Aaron |last4=Boonma |first4=Prapaporn |last5=Oezguen |first5=Numan |last6=Ross |first6=Caná L. |last7=Luna |first7=Ruth Ann |last8=Runge |first8=Jessica |last9=Versalovic |first9=James |last10=Peniche |first10=Alex |last11=Dann |first11=Sara M. |date=October 2017 |title=Next-Generation Probiotics Targeting ''Clostridium difficile'' through Precursor-Directed Antimicrobial Biosynthesis |journal=Infection and Immunity |volume=85 |issue=10 |pages=e00303–17 |doi=10.1128/IAI.00303-17 |issn=1098-5522 |pmc=5607411 |pmid=28760934}}</ref>
	Topical pure or nearly pure glycerol is an effective treatment for psoriasis, burns, bites, cuts, rashes, bedsores, and calluses. It can be used orally to eliminate halitosis, as it is a contact bacterial desiccant. The same property makes it very helpful with periodontal disease; it penetrates biofilm quickly and eliminates bacterial colonies.
			Glycerol has also been incorporated as a component of ] formulations in the field of ].<ref>{{Cite journal|last1=Atala|first1=Anthony|last2=Yoo|first2=James J.|last3=Carlos Kengla|last4=Ko|first4=In Kap|last5=Lee|first5=Sang Jin|last6=Kang|first6=Hyun-Wook|date=March 2016|title=A 3D bioprinting system to produce human-scale tissue constructs with structural integrity|journal=Nature Biotechnology|volume=34|issue=3|pages=312–319|doi=10.1038/nbt.3413|pmid=26878319|s2cid=9073831|issn=1546-1696}}</ref> The glycerol content acts to add viscosity to the bio-ink without adding large protein, saccharide, or glycoprotein molecules.
	===Botanical extracts===		===Botanical extracts===
	When utilized in 'tincture' method extractions specifically, as a 10% solution, glycerol prevents tannins from precipitating in ethanol extracts of plants (]). It is also used as a substitute for ethanol as a solvent in preparing herbal extractions. It is less extractive when utilized in tincture methodology and is approximately 30% more slowly absorbed by the body resulting in a much lower glycemic load. ] manufacturers often extract herbs in hot water before adding glycerin to make ].<ref>		When utilized in "tincture" method extractions, specifically as a 10% solution, glycerol prevents tannins from precipitating in ethanol extracts of plants (]s). It is also used as an "alcohol-free" alternative to ethanol as a solvent in preparing herbal extractions. It is less extractive when utilized in a standard tincture methodology. Alcohol-based tinctures can also have the alcohol removed and replaced with glycerol for its preserving properties. Such products are not "alcohol-free" in a scientific or FDA regulatory sense, as glycerol contains three hydroxyl groups. ] manufacturers often extract herbs in hot water before adding glycerol to make ]s.<ref>{{cite journal |last1=Long |first1=Walter S. |title=The Composition of Commercial Fruit Extracts |journal=Transactions of the Kansas Academy of Science |date=14 January 1916 |volume=28 |pages=157–161 |doi=10.2307/3624347 |jstor=3624347 }}</ref><ref> {{webarchive |url=https://web.archive.org/web/20071012040650/https://newhope.com/nutritionsciencenews/NSN_backs/Apr_99/backtalk.cfm |date=12 October 2007}} newhope.com</ref>
	Walter S. Long. ''The Composition of Commercial Fruit Extracts'' Transactions of the Kansas Academy of Science (1903-), Vol. 28, Jan. 14, 1916 – Jan. 13, 1917 (Jan. 14, 1916 - Jan. 13, 1917), pp. 157–161 doi:10.2307/3624347</ref><ref></ref>
			When used as a primary "true" alcohol-free botanical extraction solvent in non-tincture based methodologies, glycerol has been shown to possess a high degree of extractive versatility for botanicals including removal of numerous constituents and complex compounds, with an extractive power that can rival that of alcohol and water–alcohol solutions.<ref>{{cite web|url = https://www.aciscience.org/docs/Glycerine_-_an_overview.pdf |website =aciscience.org|archive-url= https://web.archive.org/web/20190601153919/http://www.aciscience.org/docs/glycerine_-_an_overview.pdf |archive-date=1 June 2019 |title = Glycerine: An Overview |publisher = The Soap and Detergent Association|date = 1990|url-status = live}}</ref> That glycerol possesses such high extractive power assumes it is utilized with dynamic (critical) methodologies as opposed to standard passive "tincturing" methodologies that are better suited to alcohol. Glycerol possesses the intrinsic property of not denaturing or rendering a botanical's constituents inert like alcohols (], ], and so on) do. Glycerol is a stable preserving agent for botanical extracts that, when utilized in proper concentrations in an extraction solvent base, does not allow inverting or mitigates ] of a finished extract's constituents, even over several years.{{citation needed |date=September 2014}} Both glycerol and ethanol are viable preserving agents. Glycerol is ] in its action, and ethanol is bactericidal in its action.<ref>Lawrie, James W. (1928) ''Glycerol and the glycols – production, properties and analysis''. The Chemical Catalog Company, Inc., New York, NY.</ref><ref>Leffingwell, Georgia and Lesser, Miton (1945) ''Glycerin – its industrial and commercial applications''. Chemical Publishing Co., Brooklyn, NY.{{page needed |date=December 2019}}</ref><ref>''The manufacture of glycerol'' – Vol. III (1956). The Technical Press, LTD., London.{{page needed |date=December 2019}}</ref>
			===Electronic cigarette liquid===
	When used as a primary true alcohol-free botanical extraction solvent in innovative non-tincture based methodologies, glycerol has been shown, both in literature and through extraction applications, to possess a high degree of extractive versatility for botanicals including removal of numerous constituents and complex compounds, with an extractive power between water and ethanol. Glycerol is a stable preserving agent for botanical extracts that, when utilized in proper concentrations in an extraction solvent base, does not allow inverting or REDOX of a finished extract's constituents over several years. Both Glycerol and ethanol are viable preserving agents. Glycerol is bacteriostatic in its action, and ethanol is bactericidal in its action.<ref>GLYCEROL AND THE GLYCOLS – Production, Properties and Analysis by, James W. Lawrie, Ph.D. (1928 The Chemical Catalog Company, Inc., New York, NY)</ref><ref>GLYCERIN – Its Industrial and Commercial Applications, by Georgia Leffingwell, Ph.D. and Miton Lesser, B.S. (1945 Chemical Publishing Co., Inc., Brooklyn, NY)</ref><ref>The Manufacture of GLYCEROL – Vol. III (1956 The Technical Press, LTD., London, UK)</ref>
			] to create the vapor]]
			Glycerin, along with ], is a common component of ], a solution used with electronic vaporizers (]). This glycerol is heated with an atomizer (a heating coil often made of ] wire), producing the ] that delivers ] to the user.<ref>{{cite book|last1=Dasgupta|first1=Amitava|last2=Klein|first2=Kimberly|title=Antioxidants in Food, Vitamins and Supplements: Prevention and Treatment of Disease|date=2014|publisher=Academic Press|isbn=9780124059177|chapter-url=https://books.google.com/books?id=5iiSAgAAQBAJ&q=propylene%20glycol%20electronic%20cigarettes&pg=PA67|access-date=16 August 2017|chapter=4.2.5 Are Electronic Cigarettes Safe?|archive-date=16 April 2021|archive-url=https://web.archive.org/web/20210416173028/https://books.google.com/books?id=5iiSAgAAQBAJ&q=propylene%20glycol%20electronic%20cigarettes&pg=PA67|url-status=live}}</ref>
	===Antifreeze===		===Antifreeze===
	{{main|antifreeze}}		{{Main|Antifreeze}}
	Like ] and ], glycerol dissolved in water disrupts the ] between water molecules such that the mixture cannot form a stable crystal structure unless the temperature is significantly lowered. The minimum freezing point temperature is at about &minus;36&nbsp;°F / &minus;37.8&nbsp;°C corresponding to 60–70% glycerol in water.<ref></ref>		Like ] and propylene glycol, glycerol is a non-ionic ] that forms strong hydrogen bonds with water molecules, competing with water-water ]. This interaction disrupts the formation of ice. The minimum freezing point temperature is about {{convert|−36|F|C|order=flip}} corresponding to 70% glycerol in water.
	Glycerol was historically used as an anti-freeze for automotive applications before being replaced by ], which has a lower freezing point. While the minimum freezing point of a glycerol-water mixture is higher than an ethylene-glycol mixture, glycerol is not toxic and is being re-examined for use in automotive applications.<ref>{{cite journal | last1 = Hudgens | first1 = R. Douglas | last2 = Hercamp | first2 = Richard D. | last3 = Francis | first3 = Jaime | last4 = Nyman | first4 = Dan A. | last5 = Bartoli | first5 = Yolanda | year = 2007 | doi = 10.4271/2007-01-4000}}</ref><ref></ref>		Glycerol was historically used as an anti-freeze for automotive applications before being replaced by ethylene glycol, which has a lower freezing point. While the minimum freezing point of a glycerol-water mixture is higher than an ethylene glycol-water mixture, glycerol is not toxic and is being re-examined for use in automotive applications.<ref>{{cite book |last1= Hudgens |first1= R. Douglas |title= SAE Technical Paper Series |volume= 1 |last2= Hercamp |first2= Richard D. |last3= Francis |first3= Jaime |last4= Nyman |first4= Dan A. |last5= Bartoli |first5= Yolanda |year= 2007 |doi= 10.4271/2007-01-4000 |chapter= An Evaluation of Glycerin (Glycerol) as a Heavy Duty Engine Antifreeze/Coolant Base }}</ref><ref> {{Webarchive|url=https://web.archive.org/web/20170914125754/http://www.astmnewsroom.org/default.aspx?pageid=2115&year=2010&category=Standards%2FTechnical |date=14 September 2017}}. Astmnewsroom.org. Retrieved on 15 August 2012</ref>
	In the laboratory, glycerol is a common component of solvents for ] reagents stored at temperatures below 0&nbsp;°C due to the ] of solutions with high concentrations of glycerol. It is also used as a ] where the glycerol is dissolved in water to reduce damage by ice crystals to laboratory organisms that are stored in frozen solutions, such as ], ]s, and ].		In the laboratory, glycerol is a common component of solvents for ] ] stored at temperatures below {{convert|0|C|F}} due to the ]. It is also used as a ] where the glycerol is dissolved in water to reduce damage by ice crystals to laboratory organisms that are stored in frozen solutions, such as ], ], ]s, and mammalian embryos. Some organisms like the ] produce glycerol to survive freezing temperatures during hibernation.<ref name="Shekhovtsov-2022">{{Cite journal |last1=Shekhovtsov |first1=Sergei V. |last2=Bulakhova |first2=Nina A. |last3=Tsentalovich |first3=Yuri P. |last4=Zelentsova |first4=Ekaterina A. |last5=Meshcheryakova |first5=Ekaterina N. |last6=Poluboyarova |first6=Tatiana V. |last7=Berman |first7=Daniil I. |date=January 2022 |title=Metabolomic Analysis Reveals That the Moor Frog ''Rana arvalis'' Uses Both Glucose and Glycerol as Cryoprotectants |journal=Animals |language=en |volume=12 |issue=10 |pages=1286 |doi=10.3390/ani12101286 |issn=2076-2615 |pmc=9137551 |pmid=35625132 |doi-access=free}}</ref>
	===Chemical intermediate===		===Chemical intermediate===
			Glycerol is used to produce a variety of useful derivatives.
	Glycerol is used to produce ], or glycerol-trinitrate (GTN), which is an essential ingredient of smokeless ] and various explosives such as ], ] and propellants like ]. Reliance on soap-making to supply co-product glycerine made it difficult to increase production to meet wartime demand. Hence, synthetic glycerin processes were national defence priorities in the days leading up to World War II. GTN is commonly used to relieve '']'', taken in the form of sub-lingual tablets, or as an aerosol spray.
			] gives ], an essential ingredient of various explosives such as ], ], and propellants like ]. Nitroglycerin under the name glyceryl trinitrate (GTN) is commonly used to relieve ], taken in the form of ] tablets, patches, or as an ] spray.
	A great deal of research is being conducted to try to make value-added products from crude glycerol (typically containing 20&nbsp;% water and residual ] catalyst) obtained from biodiesel production, as an alternative to disposal by ]. The use of crude glycerin as an additive to biomass for a renewable energy source when combusted or gasified is also being explored.
	* ] production unit<ref>{{Cite journal| author = A. T. Marshall and R. G. Haverkamp | title = Production of hydrogen by the electrochemical reforming of glycerol-water solutions in a PEM electrolysis cell | year = 2008 | journal = ] | volume = 33 | issue = 17 | pages = 4649–4654 | doi = 10.1016/j.ijhydene.2008.05.029}}</ref>
	* ] (as a potential fuel additive)<ref>{{Cite journal| author = J. A. Melero, R. vanGrieken, G. Morales and M. Paniagua | title = Acidic mesoporous silica for the acetylation of glycerol: Synthesis of bioadditives to petrol fuel | year = 2007 | journal = ] | volume = 21 | issue = 3 | pages = 1782–1791 | doi = 10.1021/ef060647q}}</ref>
	*Conversion to ]<ref>{{cite press release | title = Dow achieves another major milestone in its quest for sustainable chemistries |date = 15 March 2007 | publisher = ] | url = http://www.dow.com/propyleneglycol/news/20070315b.htm}}</ref>
	* Conversion to ]<ref>{{Cite journal| author = L. Ott, M. Bicker and H. Vogel | doi = 10.1039/b506285c | title = The catalytic dehydration of glycerol in sub- and supercritical water: a new chemical process for acrolein production | journal=] | volume = 8 | issue = 2 | pages = 214–220 | year = 2006 }}</ref><ref>{{Cite journal| author = Watanabe, M. et al. | title = Acrolein synthesis from glycerol in hot-compressed water | journal = ] | year = 2007 | volume = 98 | pages = 1285–1290 | doi = 10.1016/j.biortech.2006.05.007 | pmid = 16797980 | issue = 6}}</ref>
	* Conversion to ]<ref name="Yazdani">{{Cite journal| author = S. S. Yazdani and R. Gonzalez | title = Anaerobic fermentation of glycerol: a path to economic viability for the biofuels industry | year = 2007 | journal = ] | volume = 18 | issue = 3 | pages = 213–219 | doi = 10.1016/j.copbio.2007.05.002 | laysummary = http://www.sciencedaily.com/releases/2007/06/070626115246.htm | laysource = ScienceDaily | laydate = 27 Jun 2007 | pmid = 17532205}}</ref>
	* Conversion to ],<ref>{{cite press release | publisher = ] | url = http://epoxy.dow.com/epoxy/news/2007/20070326b.htm | title = Dow Epoxy advances glycerine-to-epichlorohydrin and liquid epoxy resins projects by choosing Shanghai site |date=26 March 2007}}</ref> a raw material for ]
			Trifunctional ]s are produced from glycerol and ].
	===Fuel===
	A Kent company has claimed that glycerol can be used as an alternative to diesel.<ref>http://</ref>
			Oxidation of glycerol affords ].<ref name="ciri2">{{cite journal |last1 = Ciriminna |first1 = Rosaria |last2 = Pagliaro |first2 = Mario |year = 2003 |title = One-Pot Homogeneous and Heterogeneous Oxidation of Glycerol to Ketomalonic Acid Mediated by TEMPO |journal = Advanced Synthesis & Catalysis |volume = 345 |issue = 3 |pages = 383–388 |doi = 10.1002/adsc.200390043}}</ref> Dehydrating glycerol affords ].
			Chlorination of glycerol gives the ]:
			: {{chem2|HOCH(CH2OH)2 + HCl -> HOCH(CH2Cl)(CH2OH) + H2O}}
			The same compound can be produced by hydrolysis of epichlorohydrin.<ref>{{cite journal |doi=10.1021/cr5004002 |title=Glycerol Ether Synthesis: A Bench Test for Green Chemistry Concepts and Technologies |date=2015 |last1=Sutter |first1=Marc |last2=Silva |first2=Eric Da |last3=Duguet |first3=Nicolas |last4=Raoul |first4=Yann |last5=Métay |first5=Estelle |last6=Lemaire |first6=Marc |journal=Chemical Reviews |volume=115 |issue=16 |pages=8609–8651 |pmid=26196761 |url=https://hal.archives-ouvertes.fr/hal-01312971/file/ChemRev_2015_115_8609-8651.pdf }}</ref>
			===Vibration damping===
			Glycerol is used as fill for ]s to damp vibration. External vibrations, from compressors, engines, pumps, etc., produce ] vibrations within ]s that can cause the needle to move excessively, giving inaccurate readings. The excessive swinging of the needle can also damage internal gears or other components, causing premature wear. Glycerol, when poured into a gauge to replace the air space, reduces the harmonic vibrations that are transmitted to the needle, increasing the lifetime and reliability of the gauge.<ref>''Pneumatic Systems: Principles and Maintenance'' by S. R. Majumdar. McGraw-Hill, 2006, p. 74 {{ISBN?}}</ref>
			===Niche uses===
			====Entertainment industry====
			Glycerol is used by set decorators when filming scenes involving water to prevent an area meant to look wet from drying out too quickly.<ref> reagent.co.uk</ref>
			Glycerine is also used in the generation of ] as a component of the fluid used in ]s as a replacement for ], which has been shown to be an irritant if exposure is prolonged.
			====Ultrasonic couplant====
			Glycerol can be sometimes used as replacement for water in ], as it has favourably higher ] (2.42&nbsp;MRayl versus 1.483&nbsp;MRayl for water) while being relatively safe, non-toxic, non-corrosive and relatively low cost.<ref> {{Webarchive|url=https://web.archive.org/web/20161027055440/https://www.nde-ed.org/GeneralResources/MaterialProperties/UT/ut_matlprop_liquids.htm |date=27 October 2016}} nde-ed.org</ref>
			===Internal combustion fuel===
			Glycerol is also used to power diesel generators supplying electricity for the ] ] series of electric race cars.<ref>. fiaformulae.com. 13 September 2014</ref>
			===Research on additional uses===
			Research continues into potential ] products of glycerol obtained from biodiesel production.<ref>{{cite journal |doi= 10.1002/ep.10225 |title= The glycerin glut: Options for the value-added conversion of crude glycerol resulting from biodiesel production |year= 2007 |last1= Johnson |first1= Duane T. |last2= Taconi |first2= Katherine A. |journal= Environmental Progress |volume= 26 |issue= 4 |pages= 338–348|bibcode= 2007EnvPr..26..338J }}</ref> Examples (aside from combustion of waste glycerol):
			* ] ] production.<ref>{{cite journal |author1= Marshall, A. T. |author2 =Haverkamp, R. G. |title= Production of hydrogen by the electrochemical reforming of glycerol-water solutions in a PEM electrolysis cell |year= 2008 |journal= ] |volume= 33 |issue= 17 |pages= 4649–4654 |doi= 10.1016/j.ijhydene.2008.05.029|bibcode =2008IJHE...33.4649M }}</ref>
			* ] is a potential fuel additive.<ref>{{cite journal |title= Acidic mesoporous silica for the acetylation of glycerol: Synthesis of bioadditives to petrol fuel |year= 2007 |journal= ] |volume= 21 |issue= 3 |pages= 1782–1791 |doi= 10.1021/ef060647q |last1= Melero |first1= Juan A. |last2= Van Grieken |first2= Rafael |last3= Morales |first3= Gabriel |last4= Paniagua |first4= Marta}}</ref>
			* Additive for ] thermoplastic.<ref>{{Cite journal|last1=Özeren|first1=Hüsamettin D.|last2=Olsson|first2=Richard T.|last3=Nilsson|first3=Fritjof|last4=Hedenqvist|first4=Mikael S. |date=2020-02-01|title=Prediction of plasticization in a real biopolymer system (starch) using molecular dynamics simulations |journal=Materials & Design |language=en |volume=187|pages=108387|doi=10.1016/j.matdes.2019.108387|issn=0264-1275|doi-access=free}}</ref><ref>{{Cite journal|last1=Özeren|first1=Hüsamettin Deniz|last2=Guivier|first2=Manon|last3=Olsson|first3=Richard T.|last4=Nilsson|first4=Fritjof|last5=Hedenqvist|first5=Mikael S. |date=2020-04-07|title=Ranking Plasticizers for Polymers with Atomistic Simulations; PVT, Mechanical Properties and the Role of Hydrogen Bonding in Thermoplastic Starch |journal=ACS Applied Polymer Materials |volume=2|issue=5|pages=2016–2026|doi=10.1021/acsapm.0c00191|doi-access=free}}</ref>
			* Conversion to various other chemicals:
			** ]<ref>{{cite press release |title= Dow achieves another major milestone in its quest for sustainable chemistries |date= 15 March 2007 |publisher= ] |url= https://www.dow.com/propyleneglycol/news/20070315b.htm |access-date= 13 July 2007 |archive-url= https://web.archive.org/web/20090916061724/https://www.dow.com/propyleneglycol/news/20070315b.htm |archive-date= 16 September 2009 |url-status= dead }}</ref>
			** ]<ref>{{cite journal |doi= 10.1039/b506285c |title= The catalytic dehydration of glycerol in sub- and supercritical water: a new chemical process for acrolein production |journal= ] |volume= 8 |issue= 2 |pages= 214–220 |year= 2006 |last1= Ott |first1= L. |last2= Bicker |first2= M. |last3= Vogel |first3= H.}}</ref><ref>{{cite journal |title= Acrolein synthesis from glycerol in hot-compressed water |journal= ] |year= 2007 |volume= 98 |pages= 1285–1290 |doi= 10.1016/j.biortech.2006.05.007 |pmid= 16797980 |issue= 6 |last1= Watanabe |first1= Masaru |last2= Iida |first2= Toru |last3= Aizawa |first3= Yuichi |last4= Aida |first4= Taku M. |last5= Inomata |first5= Hiroshi|bibcode= 2007BiTec..98.1285W }}</ref><ref>{{Cite journal |last1=Abdullah |first1=Anas |last2=Zuhairi Abdullah |first2=Ahmad |last3=Ahmed |first3=Mukhtar |last4=Khan |first4=Junaid |last5=Shahadat |first5=Mohammad |last6=Umar |first6=Khalid |last7=Alim |first7=Md Abdul |date=March 2022 |title=A review on recent developments and progress in sustainable acrolein production through catalytic dehydration of bio-renewable glycerol |url=https://linkinghub.elsevier.com/retrieve/pii/S0959652622005145 |journal=Journal of Cleaner Production |language=en |volume=341 |pages=130876 |doi=10.1016/j.jclepro.2022.130876|bibcode=2022JCPro.34130876A |s2cid=246853148 }}</ref>
			** ]<ref name="Yazdani">{{cite journal |author1= Yazdani, S. S. |author2 =Gonzalez, R. |title= Anaerobic fermentation of glycerol: a path to economic viability for the biofuels industry |year= 2007 |journal= ] |volume= 18 |issue= 3 |pages= 213–219 |doi= 10.1016/j.copbio.2007.05.002 |pmid= 17532205}}</ref><ref>{{cite press release |date=27 June 2007 |title=Engineers Find Way To Make Ethanol, Valuable Chemicals From Waste Glycerin |website=ScienceDaily |url=https://www.sciencedaily.com/releases/2007/06/070626115246.htm}}</ref>
			** ],<ref>{{cite press release |publisher= ] |url= https://epoxy.dow.com/epoxy/news/2007/20070326b.htm |title= Dow Epoxy advances glycerine-to-epichlorohydrin and liquid epoxy resins projects by choosing Shanghai site |date= 26 March 2007 |access-date= 21 February 2022 |archive-date= 8 December 2011 |archive-url= https://web.archive.org/web/20111208095306/http://epoxy.dow.com/epoxy/news/2007/20070326b.htm |url-status= live }}</ref> a raw material for ]
	==Metabolism==		==Metabolism==
	Glycerol is a precursor for synthesis of ]s and of ]s in the liver and ]. When the body uses stored fat as a source of energy, glycerol and ]s are released into the bloodstream. In some organisms, the glycerol component can be converted into ] by the ] and, thus, provide energy for cellular metabolism .		Glycerol is a precursor for synthesis of ]s and of ]s in the liver and ]. When the body uses stored fat as a source of energy, glycerol and ]s are released into the bloodstream.
			Glycerol is mainly metabolized in the liver. Glycerol injections can be used as a simple test for liver damage, as its rate of absorption by the liver is considered an accurate measure of liver health. Glycerol metabolism is reduced in both cirrhosis and ].<ref>Glycerol clearance in alcoholic liver disease. Gut (British Society of Gastroenterology). 1982 Apr; 23(4): 257–264. D G Johnston, K G Alberti, R Wright, P G Blain</ref><ref>"Fatty liver disrupts glycerol metabolism in gluconeogenic and lipogenic pathways in humans". September 2018 ''The Journal of Lipid Research'', 59, 1685–1694. Jeffrey D. Browning, Eunsook S. Jin1, Rebecca E. Murphy, and Craig R. Malloy</ref>
	Before glycerol can enter the pathway of ] or ] (depending on physiological conditions), it must be converted to their intermediate ] in the following steps:
	{|class="toccolours" border="0" style="font-size:90%" align="center"
			Blood glycerol levels are highly elevated during ], and is believed to be the cause of reduced fertility in patients who suffer from diabetes and metabolic syndrome. Blood glycerol levels in diabetic patients average three times higher than healthy controls. Direct glycerol treatment of testes has been found to cause significant long-term reduction in sperm count. Further testing on this subject was abandoned due to the unexpected results, as this was not the goal of the experiment.<ref>''Molecular Human Reproduction'', Volume 23, Issue 11, November 2017, pp. 725–737</ref>
			Circulating glycerol does not ] proteins as do ] or fructose, and does not lead to the formation of ]s (AGEs). In some organisms, the glycerol component can enter the ] pathway directly and, thus, provide energy for cellular metabolism (or, potentially, be converted to glucose through ]).
			Before glycerol can enter the pathway of glycolysis or gluconeogenesis (depending on physiological conditions), it must be converted to their intermediate ] in the following steps:
			<div class="toccolours" style="font-size:90%; margin:auto; display: flex; overflow-x: auto">
			{{Biochem reaction subunit|compound=Glycerol|image=Glycerin Skelett.svg|image_size=100}}
			{{Biochem reaction subunit|enzyme=Glycerol kinase|for_subst=ATP|for_prod=ADP}}
			{{Biochem reaction subunit|compound=Glycerol-3-phosphate|image=Glycerol-3-phosphate.png|image_size=100}}
			{{Biochem reaction subunit|enzyme=Glycerol-3-phosphate dehydrogenase|direction=reversible|for_subst=NAD<sup>+</sup>|for_prod=NADH|rev_prod=NAD<sup>+</sup>|rev_subst=NADH}}
			{{Biochem reaction subunit|compound=Dihydroxyacetone phosphate|image=DHAP struct.svg|image_size=125}}
			{{Biochem reaction subunit|enzyme=Triosephosphate isomerase|direction=reversible}}
			{{Biochem reaction subunit|compound=Glyceraldehyde 3-phosphate|image=D-Glycerinaldehyde 3-phosphate Structural Formula V1.svg|image_size=150px}}
			</div>
			The enzyme ] is present mainly in the liver and kidneys, but also in other body tissues, including muscle and brain.<ref>{{cite journal |pmc=1163884|pmid=183753|year=1976|last1=Tildon|first1=J. T.|title=Mitochondrial glycerol kinase activity in rat brain|journal=The Biochemical Journal|volume=157|issue=2|pages=513–516|last2=Stevenson|first2=J. H. Jr.|last3=Ozand|first3=P. T.|doi=10.1042/bj1570513}}</ref><ref>{{cite journal |title=Glycerol kinase activities in muscles from vertebrates and invertebrates|pmid=5801671 |pmc= 1187734 |volume=112|issue=4|date=May 1969|journal=Biochem. J.|pages=465–474|last1=Newsholme|first1=E. A.|last2=Taylor|first2=K|doi=10.1042/bj1120465}}</ref><ref>{{cite journal |vauthors= Jenkins, BT, Hajra, AK |date= 1976 |title= Glycerol Kinase and Dihydroxyacetone Kinase in Rat Brain |journal= Journal of Neurochemistry |volume= 26 |issue= 2 |pages= 377–385 |doi= 10.1111/j.1471-4159.1976.tb04491.x |pmid= 3631 |hdl= 2027.42/65297 |s2cid= 14965948 |url= https://deepblue.lib.umich.edu/bitstream/2027.42/65297/1/j.1471-4159.1976.tb04491.x.pdf |hdl-access= free |access-date= 27 August 2019 |archive-date= 21 February 2022 |archive-url= https://web.archive.org/web/20220221143240/https://deepblue.lib.umich.edu/bitstream/handle/2027.42/65297/j.1471-4159.1976.tb04491.x.pdf;jsessionid=27E5DB761F19C9F26C4F8EF4EDC33819?sequence=1 |url-status= live }}</ref> In adipose tissue, glycerol 3-phosphate is obtained from ] with the enzyme ].
			==Toxicity and safety==
			Glycerol has very low toxicity when ingested; its ] oral dose for rats is 12600&nbsp;mg/kg and 8700&nbsp;mg/kg for mice. It does not appear to cause toxicity when inhaled, although changes in cell maturity occurred in small sections of lung in animals under the highest dose measured. A sub-chronic 90-day nose-only inhalation study in Sprague–Dawley (SD) rats exposed to 0.03, 0.16 and 0.66&nbsp;mg/L glycerin (Per liter of air) for 6-hour continuous sessions revealed no treatment-related toxicity other than minimal ] of the ] lining at the base of the ] in rats exposed to 0.66&nbsp;mg/L glycerin.<ref>{{cite journal | year = 2017 | title = Toxicity of the main electronic cigarette components, propylene glycol, glycerin, and nicotine, in Sprague–Dawley rats in a 90-day OECD inhalation study complemented by molecular endpoints | journal = Food and Chemical Toxicology | volume = 109 | issue = Pt 1| pages = 315–332 | doi = 10.1016/j.fct.2017.09.001 | last1 = Phillips | first1 = Blaine | last2 = Titz | first2 = Bjoern | last3 = Kogel | first3 = Ulrike | last4 = Sharma | first4 = Danilal | last5 = Leroy | first5 = Patrice | last6 = Xiang | first6 = Yang | last7 = Vuillaume | first7 = Grégory | last8 = Lebrun | first8 = Stefan | last9 = Sciuscio | first9 = Davide | last10 = Ho | first10 = Jenny | last11 = Nury | first11 = Catherine | last12 = Guedj | first12 = Emmanuel | last13 = Elamin | first13 = Ashraf | last14 = Esposito | first14 = Marco | last15 = Krishnan | first15 = Subash | last16 = Schlage | first16 = Walter K. | last17 = Veljkovic | first17 = Emilija | last18 = Ivanov | first18 = Nikolai V. | last19 = Martin | first19 = Florian | last20 = Peitsch | first20 = Manuel C. | last21 = Hoeng | first21 = Julia | last22 = Vanscheeuwijck | first22 = Patrick| pmid = 28882640 | doi-access = free }}</ref><ref>{{cite journal | last1 = Renne | first1 = R. A. | last2 = Wehner | first2 = A. P. | last3 = Greenspan | first3 = B. J. | last4 = Deford | first4 = H. S. | last5 = Ragan | first5 = H. A. | last6 = Westerberg | first6 = R. B. | year = 1992 | title = 2-Week and 13-Week Inhalation Studies of Aerosolized Glycerol in Rats | journal = International Forum for Respiratory Research | volume = 4 | issue = 2| pages = 95–111 | doi = 10.3109/08958379209145307| bibcode = 1992InhTx...4...95R }}</ref>
			===Glycerol intoxication===
			Excessive consumption by children can lead to glycerol intoxication.<ref>{{Cite web |last=Burrell |first=Chloe |date=2023-06-02 |title=Perth and Kinross parents warned as 'intoxicated' kids hospitalised by slushy drinks |url=https://www.thecourier.co.uk/fp/news/perth-kinross/4445065/perth-kinross-warning-slushy-drinks/ |access-date=2023-06-03 |website=The Courier |language=en-GB}}</ref> Symptoms of intoxication include ], ] and a ]. While intoxication as a result of excessive glycerol consumption is rare and its symptoms generally mild, occasional reports of hospitalization have occurred.<ref>{{Cite web |title=Toddler 'turned grey and passed out' after drinking Slush Puppie |url=https://www.bbc.com/news/articles/c725pzqzdgno |access-date=2024-07-31|date=2024-07-31 |website=www.bbc.com |language=en-GB}}</ref> In the United Kingdom in August 2023, manufacturers of syrup used in ]s were advised to reduce the amount of glycerol in their formulations by the Food Standards Agency to reduce the risk of intoxication.<ref>{{Cite web |title='Not suitable for under-4s': New industry guidance issued on glycerol in slush-ice drinks |url=https://www.food.gov.uk/news-alerts/news/not-suitable-for-under-4s-new-industry-guidance-issued-on-glycerol-in-slush-ice-drinks |access-date=2023-08-11 |website=Food Standards Agency |language=en}}</ref>
			] advises that slush ice drinks containing glycerol should not be given to children under the age of 4, owing to the risk of intoxication. It also recommends that businesses do not use ] offers for the drinks in venues where children under the age of 10 are likely to consume them, and that products should be appropriately labelled to inform consumers of the presence of glycerol.<ref>{{Cite web |title=Glycerol in slush ice drinks {{!}} Food Standards Scotland |url=https://www.foodstandards.gov.scot/consumers/food-safety/buying-food-eating-out/glycerol-in-slush-ice-drinks |access-date=2024-08-04 |website=www.foodstandards.gov.scot}}</ref>
			==Historical cases of contamination with diethylene glycol==
			On 4 May 2007, the FDA advised all U.S. makers of medicines to test all batches of glycerol for ] contamination.<ref>{{cite web |publisher= U.S. Food and Drug Administration |url= https://www.fda.gov/bbs/topics/NEWS/2007/NEW01628.html |title= FDA Advises Manufacturers to Test Glycerin for Possible Contamination |date= 4 May 2007 |access-date= 8 May 2007 |archive-date= 7 May 2007 |archive-url= https://web.archive.org/web/20070507074219/http://www.fda.gov/bbs/topics/NEWS/2007/NEW01628.html |url-status= live}}</ref> This followed an occurrence of ] resulting from a falsified import customs declaration by Panamanian import/export firm Aduanas Javier de Gracia Express, S. A. The cheaper diethylene glycol was relabeled as the more expensive glycerol.<ref>{{cite news |author= Walt Bogdanich |date= 6 May 2007 |url= https://www.nytimes.com/2007/05/06/world/06poison.html |title= From China to Panama, a Trail of Poisoned Medicine |work= The New York Times |access-date= 8 May 2007 |author-link= Walt Bogdanich |archive-date= 26 September 2015 |archive-url= https://web.archive.org/web/20150926084342/http://www.nytimes.com/2007/05/06/world/06poison.html |url-status= live }}</ref><ref>{{cite news |date= 20 February 2013 |url= https://www.topmastersinpublichealth.com/10-biggest-medical-scandals-in-history |title= 10 Biggest Medical Scandals in History |access-date= 21 February 2022 |archive-date= 8 January 2022 |archive-url= https://web.archive.org/web/20220108074814/https://www.topmastersinpublichealth.com/10-biggest-medical-scandals-in-history/ |url-status= live }}</ref> Between 1990 and 1998, incidents of DEG poisoning reportedly occurred in Argentina, Bangladesh, India, and Nigeria, and resulted in hundreds of deaths. In 1937, more than one hundred people died in the United States after ingesting DEG-contaminated elixir sulfanilamide, a drug used to treat infections.<ref>{{Cite journal|last=Lang|first=Les|date=2007-07-01|title=FDA Issues Statement on Diethylene Glycol and Melamine Food Contamination|url=https://www.gastrojournal.org/article/S0016-5085(07)00995-X/abstract|journal=Gastroenterology|language=en|volume=133|issue=1|pages=5–6|doi=10.1053/j.gastro.2007.05.013|pmid=17631118|issn=0016-5085|access-date=25 December 2020|archive-date=21 February 2022|archive-url=https://web.archive.org/web/20220221143257/https://www.gastrojournal.org/article/S0016-5085%2807%2900995-X/fulltext|url-status=live|doi-access=free}}</ref>
			==Etymology==
			The origin of the ''gly-'' and ''glu''- prefixes for ]s and sugars is from ] {{lang|grc|γλυκύς}} ''glukus'' which means sweet.<ref> {{Webarchive|url=https://web.archive.org/web/20210430152747/https://www.dictionary.com/browse/glyco- |date=30 April 2021}}, dictionary.com</ref> Name ''glycérine'' was coined ca. 1811 by ] to denote what was previously called "sweet principle of fat" by its discoverer ]. It was borrowed into English ca. 1838 and in the 20th c. displaced by 1872 term glycerol featuring an alcohols' suffix -ol.
			==Properties==
			Table of thermal and physical properties of saturated liquid glycerin:<ref>{{Cite book |last=Holman |first=Jack P. |title=Heat Transfer |publisher=McGraw-Hill Companies, Inc. |year=2002 |isbn=9780072406559 |edition=9th |location=New York, NY |pages=600–606 |language=English}}</ref><ref>{{Cite book |last=Incropera 1 Dewitt 2 Bergman 3 Lavigne 4 |first=Frank P. 1 David P. 2 Theodore L. 3 Adrienne S. 4 |title=Fundamentals of Heat and Mass Transfer |publisher=John Wiley and Sons, Inc. |year=2007 |isbn=9780471457282 |edition=6th |location=Hoboken, NJ |pages=941–950 |language=English}}</ref>
			: {|class="wikitable mw-collapsible mw-collapsed"
			!Temperature (°C)
			!] (kg/m<sup>3</sup>)
			!] (kJ/kg·K)
			!] (m<sup>2</sup>/s)
			!] (W/m·K)
			!] (m<sup>2</sup>/s)
			!]
			!] (K<sup>−1</sup>)
	|-		|-
			|0
	| bgcolor="lightgreen" align="center" | Glycerol
			|1276.03
	| bgcolor="pink" colspan="2" align="center" | ]
			|2.261
	| bgcolor="lightgreen" align="center" | ]
			|{{val|8.31e-3}}
	| bgcolor="pink" colspan="2" align="center" | ]
			|0.282
	| bgcolor="lightgreen" align="center" | ]
			|{{val|9.83e-8}}
	| bgcolor="pink" colspan="2" align="center" | ]
			|84700
	| bgcolor="lightgreen" align="center" | ]
			|{{val|4.7e-4}}
	|-		|-
			|10
	| rowspan="3" align="center" | ]
			|1270.11
	| valign="bottom" align="center" | ATP
			|2.319
	| valign="bottom" align="center" | ADP
			|{{val|3.00e-3}}
	| rowspan="3" align="center" | ]
			|0.284
	| valign="bottom" align="center" | FAD<sup></sup>
			|{{val|9.65e-8}}
	| valign="bottom" align="center" | FADH2<br />
			|31000
	| rowspan="3" align="center" | ]
			|{{val|4.7e-4}}
	|
	|
	| rowspan="2" align="center" | ]
	|-		|-
			|20
	| colspan="2" align="center" | ]
			|1264.02
	| colspan="2" align="center" | ]
			|2.386
	| colspan="2" align="center" | ]
			|{{val|1.18e-3}}
			|0.286
			|{{val|9.47e-8}}
			|12500
			|{{val|4.8e-4}}
	|-		|-
			|30
	| valign="top" |
			|1258.09
	| valign="top" |
			|2.445
	| valign="top" align="center" | NAD<sup>+</sup>
			|{{val|5.00e-4}}
	| valign="top" align="center" | NADH<br />
			|0.286
	| valign="top" |
			|{{val|9.29e-8}}
	| valign="top" |
			|5380
	| valign="top" |
			|{{val|4.8e-4}}
			|-
			|40
			|1252.01
			|2.512
			|{{val|2.20e-4}}
			|0.286
			|{{val|9.14e-8}}
			|2450
			|{{val|4.9e-4}}
			|-
			|50
			|1244.96
			|2.583
			|{{val|1.50e-4}}
			|0.287
			|{{val|8.93e-8}}
			|1630
			|{{val|5.0e-4}}
	|}		|}
	The enzyme ] is present only in the liver. In adipose tissue, glycerol 3-phosphate is obtained from ] (DHAP) with the enzyme ].
	Glycerol has very low toxicity when ingested; its ] oral dose for rats is 12600 mg/kg and 8700 mg/kg for mice.<ref>Safety data for glycerol http://msds.chem.ox.ac.uk/GL/glycerol.html</ref>
	== Historical cases of contamination with diethylene glycol ==
	Glycerine and diethylene glycol are similar in appearance, smell, and taste. The US ] was passed following the 1937 "]" incident of poisoning caused by diethylene glycol contamination of medicine.
	On May 4, 2007, the US ] advised all US makers of medicines to test all batches of glycerine for the toxic ].<ref>U.S. Food and Drug Administration. Released May 4, 2007. Last retrieved May 8, 2007.</ref> This follows an occurrence of 100 fatal poisonings in ] resulting from a Chinese factory deliberately falsifying records in order to export the cheaper diethylene glycol as the more expensive glycerol.<ref>]. New York Times. Published: May 6, 2007. Last retrieved May 8, 2007.</ref>
	==Additional physical properties==
	Its ] is 64.00&nbsp;mN/m at 20 °C , and it has a ] of -0.0598&nbsp;mN/(m K).<ref name="surface-tension.de">{{Cite web|url=http://www.surface-tension.de/|title=Surface tension values of some common test liquids for surface energy analysis|accessdate=2010-09-05}}</ref> The surface tension makes it useful in bubble-blowing solutions.
	==See also==		==See also==
			* ]
	*] by-product
	*]		* ]
	*]		* ]
	*]s		* ]s
	*]/Soap making		* ]/]
	*]		* ]
	*]		* ]
	==References==		==References==
	{{Reflist|2}}		{{Reflist|30em}}
	==External links==		==External links==
			* {{Webarchive|url=https://web.archive.org/web/20220213002237/http://gmd.mpimp-golm.mpg.de/Spectrums/06a47467-ce25-4606-9d46-01ca6d04585f.aspx |date=13 February 2022 }}
	{{Wiktionary}}
			*
	*
	*
			{{Alcohols}}
	]
			{{Authority control}}
			]
			]
			]
			]
			]
			]
	]		]
			]
			]
	]		]
	]
	]
	]		]
	]		]
	]		]
			]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]
	]