 cr gas or dibenzoxazepine, or its 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 as a riot control agent in the late 1950s and early 1960s. ==physical properties== cr is a pale yellow crystalline solid with a pepper-like odor. it is slightly soluble in water and does not degrade in it. cr is usually presented as a microparticulate solid, in the form of suspension in a propylene glycol-based liquid. contrary to its common name, it is not a gas but a solid at room temperature. the dibenz[b,f][1,4]oxazepine moiety is present in the typical antipsychotic drug loxapine, but, unlike cr, loxapine is not reactive and is not an irritant. cr was first synthesised in 1962. these gases are usually fired in canisters (lacr) that heat up, producing an aerosol cloud at a steady rate. ==effects== cr gas is a lachrymatory agent (la), exerting its effects through activation of the trpa1 channel. its effects are approximately 6 to 10 times more powerful than those of cs gas. cr causes intense skin irritation, in particular around moist areas; blepharospasm, causing temporary blindness; 
Lachrymatory_agents Riot_control_agents