Ethyldichloroarsine Arsenical Yellow Cross (chemical warfare) Blue Cross (chemical warfare) Methyldichloroarsine List of chemical warfare agents Phenyldichloroarsine Lewisite Moscow hostage crisis chemical agent Blister agent Nettle agent Pulmonary agent Incapacitating agent Blood agent Chemical weapon List of UN numbers 1801 to 1900 Nerve agent VR (nerve agent) Pepper spray EA-3148 Novichok VX (nerve agent) Kolokol-1 Chemical weapons in World War I Chemical warfare