Toxins as Mass-Casualty Weapons By James M Madsen, MD, MPH, U S.Army Medical Research Institute of Chemical Defense (USAMRICD) Reviewed / Revised Jan 2023 View Patient Education Botulinum Toxin Ricin and Abrin Staphylococcal Enterotoxin B (SEB) "Toxin" is often loosely used to refer to any poison, but technically refers only to a poisonous chemical produced by an organism (although some toxins can now also be produced synthetically).