various marine animal mortalities involving trophic transfer of the toxin from its algal source up the food chain to higher predators. Studies in animals have shown that the lethal effects of saxitoxin can be reversed with 4-aminopyridine, but there are no studies on human subjects. As with any paralytic agent, where the acute concern is respiratory failure, mouth-to-mouth resuscitation or artificial ventilation of any means will keep a poisoned victim alive until antidote is administered or the poison wears off. Military interest Saxitoxin, by virtue of its extremely low LD50, readily lends itself to weaponization. In the past, it was considered for military use by the United States and was developed as a chemical weapon by the US military. It is known that saxitoxin was developed for both overt military use as well as for covert purposes by the CIA. Among weapons stockpiles were M1 munitions that contained either saxitoxin or botulinum toxin or a mixture of both. On the other hand, the CIA is known to have issued a small dose of saxitoxin to U-2 spy plane pilot Francis Gary Powers in the form of a small injection hidden within a silver dollar, for use in the event of his capture and detainment. After the 1969 ban on biological warfare by President Nixon, the US stockpiles of saxitoxin were destroyed, and development of saxitoxin as a military weapon ceased. However, in 1975 the CIA reported to Congress that it had kept a small amount of saxitoxin and cobra venom against Nixon's orders which was then destroyed or distributed to researchers. It is listed in schedule 1 of the Chemical Weapons Convention. The United States military isolated saxitoxin and assigned it the chemical weapon designation TZ. See also References External links Paralytic Shellfish Poisoning Neil Edwards. The Chemical Laboratories. School of Chemistry, Physics & Environmental Science. University of Sussex at Brighton. Saxitoxin - from food poisoning to chemical warfare Toxic cyanobacteria in water: A guide to their public health consequences, monitoring and management. Edited by Ingrid Chorus and Jamie Bartram, 1999. Published by World Health Organization. Alkaloids Biological toxin weapons Marine neurotoxins Carbamates Guanidine alkaloids Phycotoxins Cyanotoxins Sodium channel blockers Bacterial alkaloids Voltage-gated sodium channel blockers Non-protein ion channel toxins Geminal diols Heterocyclic compounds with 3 rings Nitrogen heterocycles