This webpage is maintained by the Centers for Disease Control and Prevention (CDC). The webpage provides information and resources on Phosgene. "Phosgene oxime is a manufactured chemical warfare agent. [...] Phosgene oxime is a type of agent called an urticant or nettle agent. This is because on contact with the skin, it produces intense itching and a rash similar to hives. [...] Phosgene oxime is also referred to as a corrosive agent because of the type of skin and tissue damage it causes.[...] Phosgene oxime was first produced in 1929, but it has never been used on the battlefield. Specific information on this chemical is very limited. [...] Phosgene oxime is colorless in its solid form and yellowish-brown when it is a liquid. [...] Phosgene oxime has a disagreeable, irritating odor. [...] Phosgene oxime is also known by its military designation, 'CX.'"
Centers for Disease Control and Prevention: http://www.cdc.gov/