500 ppm (human, 1 min)
340 ppm (rat, 30 min)
438 ppm (mouse, 30 min)
243 ppm (rabbit, 30 min)
316 ppm (guinea pig, 30 min)
1022 ppm (dog, 20 min)
145 ppm (monkey, 1 min)

LC_Lo (lowest published)

3 ppm (human, 2.83 h)
30 ppm (human, 17 min)
50 ppm (mammal, 5 min)
88 ppm (human, 30 min)
46 ppm (cat, 15 min)
50 ppm (human, 5 min)
2.7 ppm (mammal, 30 min)

US health exposure limits (NIOSH):

PEL (Permissible)

TWA 0.1 ppm (0.4 mg/m³)

REL (Recommended)

TWA 0.1 ppm (0.4 mg/m³) C 0.2 ppm (0.8 mg/m³) [15-minute]

IDLH (Immediate danger)

2 ppm

Related compounds

Thiophosgene
Formaldehyde
Carbonic acid
Urea
Carbon monoxide
Chloroformic acid

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

(what is ^YN ?)

Infobox references

Phosgene is the chemical compound with the formula COCl₂. This colorless gas gained infamy as a chemical weapon during World War I where it was responsible for about 85% of the 100,000 deaths caused by chemical weapons. It is also a valued industrial reagent and building block in synthesis of pharmaceuticals and other organic compounds. In low concentrations, its odor resembles freshly cut hay or grass. In addition to its industrial production, small amounts occur from the breakdown and the combustion of organochlorine compounds, such as those used in refrigeration systems. The chemical was named by combining the Greek words "phos" (meaning light) and "genesis" (birth); it does not mean it contains any phosphorus (cf. phosphine).

Phosgene is a planar molecule as predicted by VSEPR theory. The C=O distance is 1.18 Å, the C−Cl distance is 1.74 Å and the Cl−C−Cl angle is 111.8°. It is one of the simplest acid chlorides, being formally derived from carbonic acid.

Industrially, phosgene is produced by passing purified carbon monoxide and chlorine gas through a bed of porous activated carbon, which serves as a catalyst:

The reaction is exothermic, therefore the reactor must be cooled. Typically, the reaction is conducted between 50 and 150 °C. Above 200 °C, phosgene reverts to carbon monoxide and chlorine, K_eq(300 K) = 0.05. World production of this compound was estimated to be 2.74 million tonnes in 1989.

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