Phosgene Gas

 

Phosgene as a weapon was more potent than chlorine in that while the latter was potentially deadly it caused the victim to violently cough and choke.

 

    Phosgene caused much less coughing with the result that more of it was inhaled; it was consequently adopted by both German and Allied armies.  Phosgene often had a delayed effect; healthy soldiers were taken down with phosgene gas poisoning up to 48 hours after inhalation.