The U.S. is investigating claims that Islamic State militants used chemical weapons against Iraqis last month, in what would be a serious escalation of the fighting in the region.
Source: www.foxnews.com
Toxic gases allegedly released; possibly chlorine; which; when inhaled, swallowed or exposed to through skin, causes difficulty in breathing, coughing, and eye and skin irritation. It is not as toxic or effective at killing as sarin, a nerve agent. It is difficult to achieve high concentrations of chlorine by dropping it from the air.
Akira Morikawa 