4712 Dibenz(b,F)-1,4-oxazepine Dibenz(b,F)-1,4-oxazepine, also known as CR gas and dibenzoxazepine, is an incapacitating agent and a lachrymatory agent. It was developed by the British Ministry of Defence as a riot control agent in the late 1950s and early 1960s. Dibenz(b,F)-1,4-oxazepine is a lachrymatory agent (LA), exerting its effects through activation of the TRPA1 channel. It is a suspected carcinogen. It is toxic, but less so than CS gas (2-chlorobenzalmalononitrile), by ingestion and exposure. However, it can be lethal in large quantities. In a poorly ventilated space, an individual may inhale a lethal dose within minutes. Death is caused by asphyxiation and pulmonary edema. The effect of CR is long-term and persistent. CR can persist on surfaces, especially porous ones, for up to 60 days. 257-07-8 9213 C13H9NO Pale yellow crystalline solid 73°C Not listed by IARC. 2014-09-08T02:41:29Z 2026-04-03T19:32:46Z http://en.wikipedia.org/wiki/CR_gas true [H]C1=C([H])C([H])=C2N=C([H])C3=C([H])C([H])=C([H])C([H])=C3OC2=C1[H] C13H9NO InChI=1S/C13H9NO/c1-3-7-12-10(5-1)9-14-11-6-2-4-8-13(11)15-12/h1-9H NPUACKRELIJTFM-UHFFFAOYSA-N 195.2167 195.068413915 Exogenous Solid CHEMBL1085100 8858 CHEM003616 DTXSID8059764 2-oxa-9-azatricyclo[9.4.0.0³,⁸]pentadeca-1(15),3,5,7,9,11,13-heptaene