Phosgene

"COCl2" redirects here. For the compound CoCl2, see Cobalt(II) chloride.
Not to be confused with phosphine, phosphene, oxalyl chloride, or phosgene oxime.
Phosgene[1]
Full structural formula with dimensions
Space-filling model

A sample case of toxic gases used in chemical warfare; the leftmost contains phosgene in a sealed capillary
Names
Preferred IUPAC name
Carbonyl dichloride[2]
Other names
  • Carbon dichloride oxide
  • Carbon oxychloride
  • Carbonyl chloride
  • CG
  • Chloroformyl chloride
  • Collongite
  • Dichloroformaldehyde
  • Dichloromethanal
  • Dichloromethanone
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.000.792 Edit this at Wikidata
EC Number
  • 200-870-3
RTECS number
  • SY5600000
UNII
UN number 1076
  • InChI=1S/CCl2O/c2-1(3)4 checkY
    Key: YGYAWVDWMABLBF-UHFFFAOYSA-N checkY
  • InChI=1/CCl2O/c2-1(3)4
    Key: YGYAWVDWMABLBF-UHFFFAOYAH
  • ClC(Cl)=O
Properties
COCl2
Molar mass 98.91 g·mol−1
Appearance Colorless gas
Odor Suffocating, like musty hay or grass[3]
Density 4.248 g/L (15 °C, gas)
1.432 g/cm3 (0 °C, liquid)
Melting point −118 °C (−180 °F; 155 K)
Boiling point 8.3 °C (46.9 °F; 281.4 K)
Insoluble, reacts[4]
Solubility Soluble in benzene, toluene, acetic acid
Decomposes in alcohol and acid
Vapor pressure 1.6 atm (20°C)[3]
−48·10−6 cm3/mol
Structure
Trigonal planar
1.17 D
Hazards
GHS labelling:
GHS05: CorrosiveGHS06: Toxic[5]
Danger
H314, H330[5]
P260, P280, P303+P361+P353+P315, P304+P340+P315, P305+P351+P338+P315, P403, P405[5]
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 0: Will not burn. E.g. waterInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
4
0
1
Flash point Non-flammable
0.1 ppm (1 ppm = 4 mg/m3)
Lethal dose or concentration (LD, LC):
  • 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)
  • 1 ppm is 4 mg/m3
[6]
  • 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)
  • 1 ppm is 4 mg/m3
[6]
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 0.1 ppm (0.4 mg/m3)[3]
REL (Recommended)
 TWA 0.1 ppm (0.4 mg/m3) C 0.2 ppm (0.8 mg/m3) [15-minute][3]
IDLH (Immediate danger)
 2 ppm[3]
1 ppm = 4 mg/m3
Safety data sheet (SDS) [1]
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Phosgene is an organic chemical compound with the formula COCl2. It is a toxic, colorless gas; in low concentrations, its musty odor resembles that of freshly cut hay or grass.[7] It can be thought of chemically as the double acyl chloride analog of carbonic acid, or structurally as formaldehyde with the hydrogen atoms replaced by chlorine atoms. Phosgene is a valued and important industrial building block, especially for the production of precursors of polyurethanes and polycarbonate plastics.

Phosgene is extremely poisonous and was used as a chemical weapon during World War I, where it was responsible for 85,000 deaths. It is a highly potent pulmonary irritant and quickly filled enemy trenches due to it being a heavy gas.

It is classified as a Schedule 3 substance under the Chemical Weapons Convention. In addition to its industrial production, small amounts occur from the breakdown and the combustion of organochlorine compounds, such as chloroform.[8]

  1. ^ Merck Index, 11th Edition, 7310.
  2. ^ Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: Royal Society of Chemistry. 2014. p. 798. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.
  3. ^ a b c d e NIOSH Pocket Guide to Chemical Hazards. "#0504". National Institute for Occupational Safety and Health (NIOSH).
  4. ^ "PHOSGENE (cylinder)". Inchem (Chemical Safety Information from Intergovernmental Organizations). International Programme on Chemical Safety and the European Commission.
  5. ^ a b c Record of Phosgene in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 16 March 2021.
  6. ^ a b "Phosgene". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  7. ^ CBRNE - Lung-Damaging Agents, Phosgene May 27, 2009
  8. ^ Wolfgang Schneider; Werner Diller. "Phosgene". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a19_411. ISBN 978-3527306732.