The toxicity (of the Greek τοξικότητα toxikótêta ) is the measurement of the capacity of a substance to cause effects harmful and bad for health on any form of life, such as an human being, a Bactérie or a plant or a substructure of this organization such as the liver. In extenso , the word can be employed to describe the toxic effects on a group of people, like a family or a population as a whole. The science which studies toxic substances is called Toxicologie.

In toxicology, the subject of such a study is made on the effect of a substance or external conditions and their noxious effects on the living organisms, fabrics, cell S or Organite S. the central concept of toxicology is that the effects depend on the amount. If water is toxic for the man with very strong amount, a contrario , there exists a threshold for toxic substances such as the Venin of snake for which there is no discernible toxic effect.

example of toxic products: Beryllium

Generally one distinguishes three types of toxic entities:

• chemical;
• biological;
• Physical.

• acute toxicity;
• long-term toxicity.

See too

• lethal Amount 50 (or DL50)