Phosgene may be produced intentionally or accidentally. It is the byproduct of certain chemical syntheses.
Type of agent: choking
Features: colorless and denser than air (accumulates in low lying places)
Smell: freshly cut hay or grass
The initial exposure may be insidious or mildly irritating and is followed by a latency period that may range from 30 minutes to 48 hours
Clinical effects are dose dependent:
(1) coughing
(2) choking
(3) dyspnea
(4) hemoptysis
(5) conjunctivitis
(6) severe pulmonary edema
(7) chemical pneumonitis
(8) respiratory failure
Early detection can be achieved by using a specific chemical indicator badge. Exposure of a mixture of p-dimethylaminobenzaldehyde and diphenylamine to phosgene will produce a yellow to orange color.
Problems in diagnosis:
(1) failure to link the initial exposure with subsequent course
(2) longer duration of the latency period
(3) misdiagnosis of a regular pneumonia or asthma
(4) misdiagnosis of exposure to biological warfare agent
