Phosgene exposure at tens of ppm can cause what?

• A. Pulmonary edema and death
• B. Irritation of eyes
• C. Nausea only
• D. Sleepiness

Answer: (A)

Phosgene is a highly toxic lung irritant, and at exposure levels of tens of parts per million its most dangerous and defining effect is injury to the lungs leading to pulmonary edema. This fluid buildup in the air sacs impairs gas exchange and can progress to respiratory failure and death. A key aspect is that edema often has a delayed onset, sometimes appearing hours after exposure, so the danger may not be immediate but can be severe. Eye irritation can occur, but the severe outcome at these exposure levels is the lung injury and potential fatal breathing difficulties. Nausea or sleepiness are not the main life-threatening effects in this context.