Types and Categories of Hazardous Chemicals

Biotoxins
           Under development for later release
Blister Agents/Vesicants
           Lewisite, sulfur mustard, nitrogen mustard, ...
Blood/Systemic Agents (Knockdown Syndrome Agents)
           Hydrogen cyanide, arsine, ...
Caustics (Acids)
           Hydrogen fluoride (hydrofluoric acid)
Choking/Lung/Pulmonary Agents (Irritant Gas Syndrome Agents)
          Ammonia, chlorine, phosgene, ...
Incapacitating Agents
          Fentanyl, QNB (BZ), ...
Long-Acting Anticoagulants
          Super warfarin
Metals
          Under development for later release
Organophosphorus Pesticides and Nerve Agents
          Sarin (GB), Soman (GD), Tabun (GA), VX
Organic Solvents (Acute Solvent Syndrome Agents)
          Under development for later release
Riot Control Agents/Tear Gas
          Chloroacetophenone (CN), chloropicrin (PS), ...
Toxic Alcohols
          Under development for later release
Vomiting Agents
          Under development for later release

Source From http://chemm.nlm.nih.gov/agentcategories.htm