The objectives in this presentation on pulmonary agents are: a historical perspective, general issues related to toxic exposure, agents and their source, mechanism, clinical effects and therapy. The history of pulmonary agents begins in 1899 when the Hague Convention bans CW. The relevance of pulmonary agents is discussed along with related compounds. Anatomy (physiology), agent distribution, protective mechanisms, clinical examples, physical assessment, and clinical considerations are all outlined in this presentation. Among the agents discussed are chlorine and phosgene, which combined, accounted for 80% of fatalities from chemical agent exposure in World War I.