Chlorobenzylidene malononitrile tear gas exposure: Rinsing with amphoteric, hypertonic, and chelating solution

Chlorobenzylidene malononitrile (CS) is the tear gas used by the police. The aim was to evaluate an amphoteric, hypertonic, and chelating rinsing solution in CS exposure.

The first (CS) group of six police officers was exposed to CS only. The second (preexposure) group of eight sprayed their faces with an aqueous, hypertonic, amphoteric, and chelating solution before CS exposure. The third (postexposure) group of eight sprayed their faces with an aqueous, hypertonic, amphoteric, and chelating solution after CS exposure. The time between exiting the CS cloud and arriving at the "ready for action" checkpoint was measured. Their facial pain both inside the CS cloud and at the checkpoint was assessed (0-10 points).

The pain level inside the CS cloud was significantly lower in the preexposed group (5.6 ± 1.1; p = 0.01) than in the CS group (9.7 ± 0.5) and in the postexposure group (9.1 ± 0.4) where it was similar. The time interval between CS exposure and arrival at the checkpoint in the preexposure group (1:26 ± 0:44 min) was significantly shorter than both in the CS group (2:28 ± 0:25 min; p = 0.04) and postexposure group (2:30 ± 0:48 min; p = 0.02) where it was not different. The residual pain at the checkpoint in the preexposure (1.1 ± 0.4) and postexposure (1.4 ± 0.7) groups was similar with a significant lower pain level than in the CS group (2.3 ± 0.5; p = 0.02).

CS decontamination with an aqueous, hypertonic, amphoteric, and chelating solution reduces facial pain, whereas prevention with it reduces pain and recovery time.