what are the different types of chemical weapons?
['Nerve agents (such as sarin, soman, cyclohexylsarin, tabun, VX)', 'Vesicating or blistering agents (such as mustards, lewisite)', 'Choking agents or lung toxicants (such as chlorine, phosgene, diphosgene)', 'Cyanides.', 'Incapacitating agents (such as anticholinergic compounds)']