Editing CR gas (section)

{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 464184921
| Name = '''CR gas'''
| ImageFile = CR gas structure.svg
| ImageClass = skin-invert-image
| ImageFile2 = Dibenzoxazepine3D.png
| ImageClass2 = bg-transparent
| PIN = Dibenzo[''b'',''f''][1,4]oxazepine
|Section1={{Chembox Identifiers
| IUPHAR_ligand = 6472
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 8858
| InChI = 1/C13H9NO/c1-3-7-12-10(5-1)9-14-11-6-2-4-8-13(11)15-12/h1-9H
| InChIKey = NPUACKRELIJTFM-UHFFFAOYAI
| PubChem = 9213
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 1085100
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C13H9NO/c1-3-7-12-10(5-1)9-14-11-6-2-4-8-13(11)15-12/h1-9H
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = NPUACKRELIJTFM-UHFFFAOYSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 257-07-8
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = C1Q77A87V1
| SMILES = N\1=C\c3c(Oc2c/1cccc2)cccc3
}}
|Section2={{Chembox Properties
| C=13|H=9|N=1|O=1
| Density = 1.160±0.10 g/cm<sup>3</sup>
| MeltingPtC = 73
| MeltingPt_notes = 
| BoilingPt = 
 }}
}}

'''CR''' gas or '''dibenzoxazepine''' (chemical name dibenz[''b'',''f''][1,4]oxazepine, is an [[incapacitating agent]] and a [[lachrymatory agent]]. CR was developed by the British [[Ministry of Defence (United Kingdom)|Ministry of Defence]] as a [[riot control agent]] in the late 1950s and early 1960s. A report from the [[Porton Down|Porton Down laboratories]] described exposure as "like being thrown blindfolded into a bed of [[stinging nettle]]s", and it earned the nickname "firegas".<ref name=":0">{{Cite journal|url = https://books.google.com/books?id=1HlXz0MRdsEC|title = The technology of riot control|last = Rosenhead|first = Jonathon|date = 23 Jul 1981|journal = New Scientist}}</ref><ref name=":1">{{Cite web|url = http://aei.pitt.edu/5538/|title = An Appraisal of Technologies of Political Control|date = 6 January 1998|access-date = 3 October 2015|via = pitt.edu|publisher = The STOA Programme, Directorate General for Research, European Parliament|last = Wright|first = Steve}}</ref>

In its effects, CR gas is very similar to [[CS gas]] (''o''-chlorobenzylidene malononitrile), but twice as potent, even though there is little structural resemblance between the two. For example, 2&nbsp;mg of dry CR causes skin redness in 10 min, 5&nbsp;mg causes burning and erythremia, and {{nowrap|20 mg{{px2}}{{mdash}}{{px2}}}}strong pain. Water usually amplifies the pain effect of CR on skin.  CR aerosols cause irritation at concentrations of 0.2&nbsp;[[Microgram|mcg]]/L, becoming intolerable at 3&nbsp;[[Microgram|mcg]]/L. The {{LD50}} of CR through air inhalation 350&nbsp;mg·min/L.<ref>Aleksandroc V.N., Emelyanov V.I. Poisonous Substances: textbook / G.A. Sokolskiy, ed. Moscow. 1990. — 272 с. ISBN 5-203-00341-6.</ref>