View source for Chloroform

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{{SI}}
{{CMG}}
==Overview==
{{chembox
| Verifiedimages = changed
| Watchedfields = changed
| verifiedrevid = 407464807
| ImageFileL1_Ref = {{chemboximage|correct|??}}
| ImageFileL1 = Chloroform displayed.png
| ImageFileR1 = Chloroform 3D.png
| ImageFile2 = File:Chloroform by Danny S. - 002.JPG 
| ImageName2 = Chloroform in its liquid state shown in a test tube
| ImageSize2 = 200px
| IUPACName = Trichloromethane
| OtherNames = Trichloromethane; formyl trichloride; methane trichloride; methyl trichloride; methenyl trichloride; TCM; freon 20; refrigerant-20; R-20; UN 1888
| Section1 = {{Chembox Identifiers
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 7V31YC746X
| InChIKey = HEDRZPFGACZZDS-UHFFFAOYAG
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 44618
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/CHCl3/c2-1(3)4/h1H
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = HEDRZPFGACZZDS-UHFFFAOYSA-N
| CASNo = 67-66-3
| CASNo_Ref = {{cascite|correct|CAS}}
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 5977
| EINECS = 200-663-8
| PubChem = 6212
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 35255
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = C13827
| SMILES = ClC(Cl)Cl
| InChI = 1/CHCl3/c2-1(3)4/h1H
| RTECS = FS9100000
| ATCCode_prefix = N01
| ATCCode_suffix = AB02
 }}
| Section2 = {{Chembox Properties
| C=1|H=1|Cl=3
| Appearance = Colorless liquid
| Odor = Heavy, ethereal odor
| Density = 1.564 g/cm<sup>3</sup> (-20 °C)<br> 1.489 g/cm<sup>3</sup> (25 °C)<br> 1.394 g/cm<sup>3</sup> (60 °C)
| MeltingPtC = -63.5
| BoilingPtC = 61.15
| Boiling_notes = <br> decomposes at 450&nbsp;°C
| VaporPressure = 0.62 kPa (-40 °C)<br> 7.89 kPa (0 °C)<br> 25.9 kPa (25 °C)<br> 313 kPa (100 °C)<br> 2.26 MPa (200 °C)
| Solubility = 1.062 g/100 mL (0 °C)<br> 0.809 g/100 mL (20 °C)<br> 0.732 g/100 mL (60 °C)
| SolubleOther = Soluble in [[benzene]]<br> Miscible in [[diethyl ether]], [[oil]]s, [[ligroin]], [[alcohol]], [[carbon tetrachloride|CCl<sub>4</sub>]], [[carbon disulfide|CS<sub>2</sub>]]
| Solubility1 = ≥ 10 g/100 mL (19 °C)
| Solvent1 = acetone
| Solubility2 = ≥ 10 g/100 mL (19 °C)
| Solvent2 = dimethyl sulfoxide
| RefractIndex = 1.4459 (20 °C)
| Lambda-max = 250 nm, 260 nm, 280 nm
| Viscosity = 0.563 cP (20 °C)
| pKa = 15.7 (20 °C)
| HenryConstant = 3.67 L·atm/mol (24 °C)
| ThermalConductivity = 0.13 W/m·K (20 °C)
 }}
| Section3 = {{Chembox Structure
| CrystalStruct =
| Coordination =
| MolShape = Tetrahedral
| Dipole = 1.15 D
 }}
| Section4 = {{Chembox Thermochemistry
|  HeatCapacity = 114.25 J/mol·K
|  Entropy = 202.9 J/mol·K
|  DeltaHf = -134.3 kJ/mol
|  DeltaGf = -71.1 kJ/mol
|  DeltaHc = 473.21 kJ/mol
}}
| Section7 = {{Chembox Hazards
| MainHazards = carcinogen<ref name=PGCH/>
|   GHSPictograms = {{GHS07}}{{GHS08}}
| GHSSignalWord = Warning
|   HPhrases = {{H-phrases|302|315|319|332|336|351|361|373}}
|   PPhrases = {{P-phrases|261|281|305+351+338}}
| EUClass = {{Hazchem Xn}} {{Hazchem Xi}}<br> [[Carcinogen|Carc. Cat. 2B]]
| NFPA-H = 2
| NFPA-F = 0
| NFPA-R = 0
| NFPA-O =
| RPhrases = {{R22}}, {{R38}}, {{R40}}, {{R48/20/22}}
| SPhrases = {{S2}}, {{S36/37}}
| FlashPt = Non-flammable
| Autoignition =
| PEL = 50 ppm (240 mg/m<sup>3</sup>)<ref name=PGCH>{{PGCH|0127}}</ref>
| IDLH = 500 ppm<ref name=PGCH/>
| REL = Ca ST 2 ppm (9.78 mg/m<sup>3</sup>) [60-minute]<ref name=PGCH/>
| LD50 = 1250 mg/kg (rats, oral)
 }}
}}

'''Chloroform''' is an [[organic compound]] with [[chemical formula|formula]] [[Carbon|C]][[Hydrogen|H]][[Chlorine|Cl]]<sub>3</sub>. It is one of the four chloromethanes.<ref name=Ullmann/> The colorless, sweet-smelling, dense liquid is a [[trihalomethane]], and is considered hazardous. Several million tons are produced annually as a precursor to [[PTFE]] and [[refrigerant]]s, but its use for refrigerants is being phased out.<ref name=Ullmann>Rossberg, M. ''et al.'' "Chlorinated Hydrocarbons" in ''Ullmann’s Encyclopedia of Industrial Chemistry'', 2006, Wiley-VCH, Weinheim. {{DOI|10.1002/14356007.a06_233.pub2}}</ref> The [[hydrogen]] attached to [[carbon]] in chloroform participates in hydrogen bonding.<ref>{{cite journal|author=Wiley G.R. and Miller S.I. |doi=10.1021/ja00765a001|title=Thermodynamic parameters for hydrogen bonding of chloroform with Lewis bases in cyclohexane. Proton magnetic resonance study|year=1972|journal=Journal of the American Chemical Society|volume=94|issue=10|pages=3287}}</ref><ref>{{cite journal|pmid=18855462|year=2008|last1=Kwak|first1=K|last2=Rosenfeld|first2=DE|last3=Chung|first3=JK|last4=Fayer|first4=MD|title=Solute-solvent complex switching dynamics of chloroform between acetone and dimethylsulfoxide-two-dimensional IR chemical exchange spectroscopy|volume=112|issue=44|pages=13906–15|doi=10.1021/jp806035w|pmc=2646412|journal=The journal of physical chemistry. B}}</ref>

==Natural occurrence==
The total global flux of chloroform through the environment is approximately 660&nbsp;000 tonnes per year, and about 90% of emissions are natural in origin. Many kinds of [[seaweed]] produce chloroform, and [[fungi]] are believed to produce chloroform in soil.

Chloroform volatilizes readily from soil and surface water and undergoes degradation in air to produce [[phosgene]], [[dichloromethane]], [[formyl chloride]], [[carbon monoxide]], [[carbon dioxide]], and [[hydrogen chloride]]. Its halflife in air ranges from 55 to 620 days. Biodegradation in water and soil is slow. Chloroform does not bioaccumulate to any significant extent in aquatic organisms.<ref name="cicad">{{citation | title=Chloroform | series=[[CICAD]] | volume=58 |  publisher=[[World Health Organization]] | year=2004 | url=http://www.who.int/ipcs/publications/cicad/en/cicad58.pdf}}</ref>

==History==
Trichloromethane was synthesized independently by two groups in 1831: [[Liebig]] carried out the [[Bond cleavage|alkaline cleavage]] of [[chloral]], whereas [[Eugène Soubeiran|Soubeirain]] obtained the compound by the action of [[chlorine bleach]] on both [[ethanol]] and [[acetone]]. In 1835, [[Jean-Baptiste Dumas|Dumas]] prepared the substance by the alkaline cleavage of [[trichloroacetic acid]]. [[Henri Victor Regnault|Regnault]] prepared trichloromethane by [[Halogenation|chlorination]] of [[monochloromethane]]. By the 1850s, chloroform was being produced on a commercial basis by using the Liebig procedure, which retained its importance until the 1960s. Today, trichloromethane — along with [[dichloromethane]] — is prepared exclusively and on a massive scale by the chlorination of methane and monochloromethane.<ref name="Ullmann" />

===Production===
In industry, chloroform is produced by heating a mixture of [[chlorine]] and either [[methyl chloride|chloromethane]] or [[methane]].<ref name=Ullmann/> At 400–500&nbsp;°C, a [[free radical halogenation]] occurs, converting these precursors to progressively more chlorinated compounds:
:CH<sub>4</sub> + Cl<sub>2</sub> → CH<sub>3</sub>Cl + [[hydrogen chloride|HCl]]
:CH<sub>3</sub>Cl + Cl<sub>2</sub> → [[Dichloromethane|CH<sub>2</sub>Cl<sub>2</sub>]] + HCl
:CH<sub>2</sub>Cl<sub>2</sub> + Cl<sub>2</sub> → CHCl<sub>3</sub> + HCl

Chloroform undergoes further chlorination to yield [[carbon tetrachloride]] (CCl<sub>4</sub>):
:CHCl<sub>3</sub> + Cl<sub>2</sub> → CCl<sub>4</sub> + HCl

The output of this process is a mixture of the four chloromethanes ([[chloromethane]], [[dichloromethane]], chloroform, and carbon tetrachloride), which can then be separated by [[distillation]].<ref name=Ullmann/>

===Deuterochloroform===
{{Main|Deuterated chloroform}}
[[Deuterated chloroform]] is an [[isotopologue]] of chloroform with a single [[deuterium]] atom. CDCl<sub>3</sub> is a common solvent used in [[NMR spectroscopy]]. Deuterochloroform is produced by the [[haloform reaction]]{{Citation needed|date=February 2012}}, the reaction of  acetone (or ethanol) with [[sodium hypochlorite]] or calcium hypochlorite.<ref name=Ullmann/> The haloform process is now obsolete for the production of ordinary chloroform. Deuterochloroform can also be prepared by the reaction of sodium deuteroxide with [[chloral hydrate]],{{Citation needed|date=December 2007}} or from ordinary chloroform.<ref>Koch, Hans A. [http://patents.ic.gc.ca/cipo/cpd/en/patent/1085423/summary.html Cholorofom Deuteration Process]. Canadian Patent 1085423. Patents.ic.gc.ca. Issued: 1980-09-09. Retrieved on 2012-08-13.</ref>

===Inadvertent formation of chloroform===
The haloform reaction can also occur inadvertently in domestic settings. [[Bleaching]] with [[hypochlorite]] generates halogenated compounds in side reactions; chloroform is the main byproduct.<ref name="bleaching">{{citation | author=Hans Ulrich Süss | contribution=Bleaching | title=Ullmann's Encyclopedia of Industrial Chemistry | edition=7th | publisher=Wiley | year=2007 | page=5}}</ref> Sodium hypochlorite solution ([[chlorine bleach]]) mixed with common household liquids such as [[acetone]], [[butanone]], [[ethanol]], or [[isopropyl alcohol]] can produce some chloroform, in addition to other compounds such as [[chloroacetone]] or [[dichloroacetone]].

==Uses==
The major use of chloroform today is in the production of the [[chlorodifluoromethane]], a major precursor to [[tetrafluoroethylene]]:
:CHCl<sub>3</sub> + 2 HF → CHClF<sub>2</sub> + 2 HCl
The reaction is conducted in the presence of a catalytic amount of [[antimony pentafluoride]]. Chlorodifluoromethane is then converted into tetrafluoroethylene, the main precursor to [[Teflon]]. Before the [[Montreal Protocol]], chlorodifluoromethane (designated as R-22) was also a popular refrigerant.

===Solvent===
Worldwide, chloroform is also used in pesticide formulations, as a solvent for fats, oils, rubber, alkaloids, waxes, [[gutta-percha]], and resins, as a cleansing agent, grain fumigant, in fire extinguishers, and in the rubber industry.<ref name="cicad" /><ref name="pth">{{citation | editor=Jerrold B. Leikin | editor2=Frank P. Paloucek | contribution=Chloroform | title=Poisoning and Toxicology Handbook | edition=4th | publisher=Informa | year=2008 | page=774}}</ref> CDCl<sub>3</sub> is a common solvent used in [[NMR spectroscopy]].

===Reagent===
As a [[reagent]], chloroform serves as a source of the dichlorocarbene CCl<sub>2</sub> group.<ref>Srebnik, M.; Laloë, E. (2001) "Chloroform" in ''Encyclopedia of Reagents for Organic Synthesis'', Wiley, {{doi|10.1002/047084289X.rc105}}</ref> It reacts with aqueous [[sodium hydroxide]] usually in the presence of a [[phase transfer catalyst]] to produce [[dichlorocarbene]], CCl<sub>2</sub>.<ref>{{OrgSynth|Vogel, E.; Klug, W.; Breuer. A.|title = <nowiki>1,6-Methano[10]annulene</nowiki>|collvol = 6|collvolpages = 731|year = 1988|prep = cv6p0731}}</ref><ref>{{OrgSynth|author = Gokel, G. W.; Widera, R. P.; Weber, W. P.|title = Phase-Transfer Hofmann Carbylamine Reaction: tert-Butyl Isocyanide|collvol = 6|collvolpages = 232|year = 1988|prep = cv6p0232}}</ref> This reagent affects ortho-formylation of activated [[aromatic rings]] such as [[phenols]], producing aryl [[aldehyde]]s in a reaction known as the [[Reimer-Tiemann reaction]]. Alternatively the [[carbene]] can be trapped by an [[alkene]] to form a [[cyclopropane]] derivative. In the [[Kharasch addition]] chloroform forms the CHCl<sub>2</sub> free radical in addition to alkenes.

The most important reaction of chloroform is that with [[hydrogen fluoride]] in the presence of antimony pentahalides to give [[monochlorodifluoromethane]] ([[CFC 22]]), a precursor in the production of polytetrafluoroethylene ([[Teflon]]).<ref name="Ullmann" />

===Anaesthetic===
[[File:Chickamauga 2009, Chloroform.jpg|thumb|left|Antique bottles of chloroform]]
Chloroform was once a widely used [[anesthesia|anesthetic]]. On 4 November 1847, the Scottish [[obstetrics|obstetrician]] [[James Young Simpson]] first used the anaesthetic qualities of chloroform on a human,<ref name="Gordon2002">{{cite book|last=Gordon|first=H. Laing|title=Sir James Young Simpson and Chloroform (1811–1870)|url=http://books.google.com/books?id=pYer05UwKBYC&pg=PA106|accessdate=11 November 2011|date=November 2002|publisher=The Minerva Group, Inc.|isbn=978-1-4102-0291-8|pages=106–109}}</ref> two guests at his dinner party. This was done as an entertainment and not as a medical procedure.

This was followed, only three days later, by the first use of chloroform on an actual patient, for a dental procedure, by [[Francis Brodie Imlach]] (1819-1891), also in [[Edinburgh]], who, under other circumstances, may have gained the same fame as Simpson.<ref>http://historyofdentistry.co.uk/index_htm_files/2004Apr2.pdf</ref>

The use of chloroform during [[surgery]] expanded rapidly thereafter in Europe. In the 1850s, chloroform was used during the birth of Queen Victoria's last two children.<ref>[http://www.ph.ucla.edu/epi/snow/victoria.html Anesthesia and Queen Victoria]. Ph.ucla.edu. Retrieved on 2012-08-13.</ref> In the United States, chloroform began to replace [[Diethyl ether|ether]] as an anesthetic at the beginning of the 20th century; however, it was quickly abandoned in favor of [[Diethyl ether|ether]] upon discovery of its toxicity, especially its tendency to cause fatal [[cardiac arrhythmia]] analogous to what is now termed "[[Intoxicative inhalant#Sudden sniffing death syndrome|sudden sniffer's death]]". Some people used chloroform as a recreational drug or to attempt suicide.<ref>{{cite journal|author=Martin, William|title=A Case of Chloroform Poisoning; Recovery|journal=Br Med J|date=3 July 1886|volume=2|issue=1331|pages=16–17|pmc=2257365|doi=10.1136/bmj.2.1331.16-a|pmid=20751619}}</ref> One possible mechanism of action for chloroform is that it increases movement of potassium ions through certain types of [[potassium channels]] in [[nerve cells]].<ref>{{Cite journal|last1 = Patel|first1 = Amanda J.|last2 = Honoré|first2 = Eric|last3 = Lesage|first3 = Florian|last4 = Fink|first4 = Michel|last5 = Romey|first5 = Georges|last6 = Lazdunski|first6 = Michel|publication-date =|date = May 1999|title = Inhalational anesthetics activate two-pore-domain background K+ channels|journal = Nature Neuroscience|volume = 2|pages = 422–426|doi = 10.1038/8084|pmid = 10321245|issue = 5}}</ref> Chloroform could also be mixed with other anesthetic agents such as ether to make C.E. mixture, or ether and [[Ethanol|alcohol]] to make [[A.C.E. mixture]].
In 1848, Hannah Greener, a 15-year-old girl who was having an infected toenail removed, died after being given the anesthetic.<ref>{{cite journal|title=An Unexplained Death: Hannah Greener and Chloroform |author= Knight, Paul R. III and Bacon, Douglas R. | year=2002 |volume = 96 |issue = 5 |journal=Anesthesiology|doi=10.1097/00000542-200205000-00030|pages=1250–3|pmid=11981167}}</ref> A number of physically fit patients died after inhaling it. However, in 1848 [[John Snow (physician)|John Snow]] developed an inhaler that regulated the dosage and so successfully reduced the number of deaths.<ref>{{cite web|last1 = Snow|first1 = John|publication-date =|year = 1858|title = On Chloroform and Other Anaesthetics and Their Action and Administration| pages = 82–85|url=http://archive.org/stream/onchloroformothe1858snow#page/82/mode/2up/search/inhaler}}</ref>

The opponents and supporters of chloroform were mainly at odds with the question of whether the complications were solely due to respiratory disturbance or whether chloroform had a specific effect on the heart. Between 1864 and 1910 numerous commissions in UK studied chloroform, but failed to come to any clear conclusions. It was only in 1911 that Levy proved in experiments with animals that chloroform can cause cardiac fibrillation. The reservations about chloroform could not halt its soaring popularity. Between about 1865 and 1920, chloroform was used in 80 to 95% of all narcoses performed in UK and German-speaking countries. In America, however, there was less enthusiasm for chloroform narcosis. In Germany the first comprehensive surveys of the fatality rate during anaesthesia were made by Gurlt between 1890 and 1897. In 1934, Killian gathered all the statistics compiled until then and found that the chances of suffering fatal complications under ether were between 1: 14,000 and 1: 28,000, whereas under chloroform the chances were between 1: 3,000 and 1: 6,000. The rise of gas anaesthesia using nitrous oxide, improved equipment for administering anaesthetics and the discovery of [[hexobarbital]] in 1932 led to the gradual decline of chloroform narcosis.<ref>Anaesthesiol Reanim. 1997;22(6):144-52. Wawersik J. Clinic of  Christian-Albrechts-Universität of Kiel. http://ncbi.nlm.nih.gov/pubmed/9487785</ref>

=== Criminal use ===
Chloroform has been reputed to be used by criminals to knock out, daze or even murder their victims. Joseph Harris was charged in 1894 with using chloroform to rob people.<ref>{{Cite news|url=http://news.google.com/newspapers?id=Ec1VAAAAIBAJ&sjid=sEANAAAAIBAJ&pg=2904,2720400&dq=chloroform+knockout&hl=en|title=Knock-out and Chloroform|publisher=[[The Philadelphia Record]]|date=9 February 1894|accessdate=31 March 2011}}</ref> In 1901, chloroform was also implicated in the murder of the American businessman [[William Marsh Rice]], the namesake of the institution now known as [[Rice University]]. Chloroform was also deemed to be a factor in the alleged murder of a woman in 1991 when she was asphyxiated while sleeping.<ref>{{cite web|url=http://news.google.com/newspapers?id=I91HAAAAIBAJ&sjid=4f8MAAAAIBAJ&pg=2367,1007950&dq=chloroform+knockout&hl=en|title=Chloroform case retrial underway|date=7 July 1993|accessdate=31 March 2011|publisher=[[Record-Journal]]}}</ref> In a 2007 plea bargain a man confessed to using [[Electroshock weapon|stun guns]] and chloroform to sexually assault minors.<ref>{{cite web|url=http://www.usatoday.com/news/nation/2007-11-06-chloroform-rapes_N.htm|title=Man admits to raping friends' daughters|date=6 November 2007|accessdate=31 March 2011|publisher=[[USA Today]]}}</ref> Use of chloroform as an [[incapacitating agent]] has become widely recognized, bordering on [[cliché]]d, due to the popularity of [[crime fiction]] authors having criminals use chloroform-soaked rags to render victims unconscious. However, it is nearly impossible to incapacitate someone using chloroform.<ref name="Anaesthesia">{{cite journal|last=Payne|first=J. P.|date=July 1998|title=The criminal use of chloroform|journal=[[Anaesthesia (journal)|Anaesthesia]]|volume=53|issue=7|pages=685–690|doi=10.1046/j.1365-2044.1998.528-az0572.x|url=http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2044.1998.528-az0572.x/pdf}}</ref> It takes at least five minutes of inhaling an item soaked in chloroform to render a person unconscious. Most criminal cases involving chloroform also involve another drug being co-administered, such as [[alcohol]] or [[diazepam]], or the victim being found to have been complicit in its administration. After a person has lost consciousness due to chloroform inhalation, a continuous volume must be administered and the chin must be supported in order to keep the tongue from obstructing the airway, a difficult procedure even for an [[anesthesiologist]]. In 1865 as a direct result of the criminal reputation chloroform had gained, medical journal ''[[The Lancet]]'' offered a "permanent scientific reputation" to anyone who could demonstrate "instantaneous insensibility" using chloroform,<ref>Medical Annotation. Chloroform amongst Thieves. ''[[The Lancet]]'', 1865; 2: 490 – 1.</ref> and {{as of|1998|lc=y}} no such demonstration has been forthcoming.<ref name="Anaesthesia"/>

==Safety==
Chloroform is well absorbed, metabolized, and eliminated rapidly by mammals after oral, inhalation, or dermal exposure. Accidental splashing into the eyes has caused irritation.<ref name="cicad" /> Prolonged dermal exposure can result in the development of sores as a result of [[Defatting (medical)|defatting]]. Elimination is primarily from lungs in the form of chloroform and carbon dioxide; less than 1% is excreted in urine.<ref name="pth" />

Chloroform is metabolized in the liver by the [[cytochrome P-450]] enzymes, by oxidation to [[phosgene]] and by reduction to the dichloromethyl [[free radical]]. Other metabolites of chloroform include [[chloromethanol]], [[hydrochloric acid]], [[hydrogen chloride]], and [[digluathionyl dithiocarbonate]], with [[carbon dioxide]] as the predominant end product of metabolism.<ref name="eot">{{citation | author=Anna M Fan | contribution=Chloroform | title=Encyclopedia of Toxicology | edition=2nd | volume=1 | publisher=Elsevier | year=2005 | pages=561–565}}</ref>

Chloroform causes depression of the central nervous system (CNS), ultimately producing deep coma and respiratory center depression.<ref name="eot" /> When ingested, chloroform caused symptoms similar to those seen following inhalation. Serious illness has followed ingestion of 7.5&nbsp;g. The mean lethal oral dose for an adult is estimated to be about 45&nbsp;g.<ref name="cicad" />

The anesthetic use of chloroform has been discontinued because it caused deaths due to respiratory and cardiac arrhythmias and failure. Following chloroform-induced anesthesia, some patients suffered nausea, vomiting, prostration, jaundice, and coma due to hepatic dysfunction. At autopsy, liver necrosis and degeneration have been observed.<ref name="cicad" />

Chloroform has induced liver tumors in mice and kidney tumors in mice and rats.<ref name="cicad" /> The hepatotoxicity and nephrotoxicity of chloroform is thought to be due largely to phosgene.<ref name="eot" />

===Conversion to phosgene===
During prolonged storage in the presence of [[oxygen]], chloroform converts slowly to [[phosgene]], releasing [[HCl]] in the process. To prevent accidents, commercial chloroform is stabilized with [[ethanol]] or [[pentene|amylene]], but samples that have been recovered or dried no longer contain any stabilizer. Amylene has been found ineffective, and the phosgene can affect analytes in samples, lipids, and nucleic acids dissolved in or extracted with chloroform.<ref>{{cite journal|url=http://pubs.acs.org/cen/safety/19980302.html|author=Turk, Eric|title=Phosgene from Chloroform|journal= Chemical & Engineering News |date=2 March 1998|volume=76|issue=9|page=6|doi=10.1021/cen-v076n009.p006}}</ref> Phosgene and HCl can be removed from chloroform by washing with saturated aqueous carbonate solutions, such as [[sodium bicarbonate]]. This procedure is simple and results in harmless products. Phosgene reacts with water to form carbon dioxide and HCl,<ref>[http://www.britannica.com/EBchecked/topic/457363/phosgene phosgene (chemical compound)]. Encyclopædia Britannica. Retrieved on 2013-08-16.</ref> and the carbonate salt neutralizes the resulting acid.

Suspected samples can be tested for phosgene using filter paper (treated with 5% [[diphenylamine]], 5% [[dimethylaminobenzaldehyde]] in alcohol, and then dried), which turns yellow in phosgene vapor. There are several colorimetric and fluorometric reagents for phosgene, and it can also be quantified with [[mass spectrometry]].

==References==
{{reflist|2}}

==External links==
{{Commons category|Chloroform}}
*[http://www.chm.bris.ac.uk/motm/chloroform/chloroformv.htm Chloroform "The Molecular Lifesaver"] An article at Oxford University providing facts about chloroform.
*[http://www.inchem.org/documents/cicads/cicads/cicad58.htm Concise International Chemical Assessment Document 58]
*IARC Summaries & Evaluations: [http://www.inchem.org/documents/iarc/vol01/chloroform.html Vol. 1 (1972)], [http://www.inchem.org/documents/iarc/vol20/chloroform.html Vol. 20 (1979)], [http://www.inchem.org/documents/iarc/suppl7/chloroform.html Suppl. 7 (1987)], [http://www.inchem.org/documents/iarc/vol73/73-05.html Vol. 73 (1999)]
*{{ICSC|0027|00}}
*{{PGCH|0127}}
*[http://webbook.nist.gov/cgi/cbook.cgi?ID=67-66-3&Units=SI&cTG=on&cTC=on&cTP=on NIST Standard Reference Database]
*[http://www.bbc.co.uk/radio4/science/thematerialworld_20050728.shtml Story on Chloroform] from BBC's The Material World (28 July 2005)
*[http://www.ncpoisoncenter.org/body.cfm?id=142 Sudden Sniffer's Death Syndrome] article at Carolinas Poison Center
*Calculation of [http://ddbonline.ddbst.de/AntoineCalculation/AntoineCalculationCGI.exe?component=Chloroform vapor pressure], [http://ddbonline.ddbst.de/DIPPR105DensityCalculation/DIPPR105CalculationCGI.exe?component=Chloroform liquid density], [http://ddbonline.ddbst.de/VogelCalculation/VogelCalculationCGI.exe?component=Chloroform dynamic liquid viscosity], [http://ddbonline.ddbst.de/DIPPR106SFTCalculation/DIPPR106SFTCalculationCGI.exe?component=Chloroform surface tension] of chloroform
*[http://chemsub.online.fr/name/chloroform.html ChemSub Online: Chloroform – Methane, trichloro-]


{{Hallucinogens}}
{{General anesthetics}}



[[Category:Organochlorides]]
[[Category:Halomethanes]]
[[Category:Hazardous air pollutants]]
[[Category:IARC Group 2B carcinogens]]
[[Category:Halogenated solvents]]
[[Category:Halogen-containing natural products]]
[[Category:Drug]]