8. Systemic toxicity

8.1 Definitions

There are two forms of systemic toxicity:

• acute toxicity, the effects of which occur after a single, strong exposure over a short period (a few hours);

• long-term toxicity (in two forms):

  • subacute, the effects of which develop progressively with moderate but repeated exposure over a period of days to weeks,

  • chronic, whose effects develop over the long term following low but repeated exposure over a long exposure period lasting months or years.

Toxicology studies are generally based on a dose/duration relationship. Toxic doses are very high in acute studies, and much lower...