Chemical Weapons Convention chlorine

There are essentially millions of chemical compounds known to humanity, but only a limited number are weaponized by conventional militaries. The Organization for the Prohibition of Chemical Weapons (OPCW), the 184-member watchdog agency enforcing the guidelines of the Chemical Weapons Convention (CWC), has identified 55 chemical agents and their precursors that can be used as weapons (OPCW, 2005). Although some of the chemicals are well known (e.g. sarin, soman, VX, mustard), other less obvious choices for chemical terrorism include industrial chemicals such as chlorine and toxic precursors, which are considered weapons of opportunity . 

From a scientific and technical point of view the major problem with so-called NLW lies in the fact that they are not non-lethal, as the Moscow theatre situation has clearly demonstrated here about 130 of the 830 hostages present in the theatre died of the effects of the gas used. This represents a percentage of approximately 16 per cent. Compared with the lethality of conventional, commonly assumed to be lethal weapons there is no significant difference the use of firearms in combat have resulted in 35 per cent fatalities, mines 20 per cent and grenades around 10 per cent.54 World War I chemical warfare agents like chlorine, phosgene and mustard gas, which are prohibited under the Chemical Weapons Convention, have an even lower lethality of around 7 per cent.55... 

During the trench warfare that dominated World War I, the immediate incentive for one of the armies to employ chlorine gas was to break through the sturdy trench fortifications that had withstood attacks with conventional weapons. Heavier-than-air chemicals offered a means to break the lines of even the best dug-in defenders. The goal became to injure or kill large numbers of entrenched forces, then overrun their positions. 

---