what is poison
In biology, poisons are substances which cause disturbances to organisms, usually by chemical reaction or other activity on the molecular scale, when a sufficient quantity is absorbed by an organism. The fields of medicine (particularly veterinary) and zoology often distinguish a poison from a toxin, and from a venom.Toxins are poisons produced by organisms in nature, and venoms are toxins which are injected by a bite or sting (this is exclusive to animals).ndeed, 2,4-D is not a poison, but classified as harmful (EU). Many substances regarded as poisons are toxic only indirectly, by toxication. An example is wood alcohol or methanol, which is not poisonous itself, but is chemically converted to toxic formaldehyde and formic acid in the liver.