'''Poison''' is any substance which acts in a pathological manner. The definition of poison is complicated, identified by the Ancient [[Greek]] philsopher and scientist [[Paracelsus]], who stated that "all substances are poisons, dependent on their dosage." Medically this is the general consensus also. Practically, however, many substances are of course innocuous in a low enough dosage - indeed one encountered in day to day life. Examples here would include nitrogen, chalk, water etc. (though water toxicity may occur following hypothalamic compromise such as after taking noradrenaline (norepinephrine in the USA) reuptake inhibitors such as MDMA/Ecstacy). Other substances are very damaging in minute doses - notably the irreversible acetylcholinesterase inhibitors such as VX and Tabun (now employed in chemical warfare), heavy metals such as lead and mercury. | '''Poison''' is any substance which acts in a pathological manner. The definition of poison is complicated, identified by the Ancient [[Greek]] philsopher and scientist [[Paracelsus]], who stated that "all substances are poisons, dependent on their dosage." Medically this is the general consensus also. Practically, however, many substances are of course innocuous in a low enough dosage - indeed one encountered in day to day life. Examples here would include nitrogen, chalk, water etc. (though water toxicity may occur following hypothalamic compromise such as after taking noradrenaline (norepinephrine in the USA) reuptake inhibitors such as MDMA/Ecstacy). Other substances are very damaging in minute doses - notably the irreversible acetylcholinesterase inhibitors such as VX and Tabun (now employed in chemical warfare), heavy metals such as lead and mercury. |