Chloropicrin is banned in war under the 1993 Chemical Weapons Convention (CWC), to which Russia is a signatory. Russia is already widely using tear gas, the Dutch defense ministry said, and called the deployment of chloropicrin a "grave violation" of the CWC.

Dutch and German intelligence agencies have gathered evidence of widespread Russian use of banned chemical weapons in Ukraine, including dropping a choking agent from drones to drive soldiers out of trenches so they can be shot,