By Little Pro on 2016-04-24 Views: Update:2018-02-09
Acute toxicity describes the adverse effects of a substance that result either from a single exposure or from multiple exposures in a short period of time (usually less than 24 hours). Acute toxicity tests in animals (i.e, rat) use mortality as the main observational endpoint in order to derive a LD50 or LC50.
Acute toxicitity studies usually include 3 routes: oral, dermal and inhalation.
A common dose-response descriptor for acute toxicity is the LD50 (Lethal Dose 50%). This is a statistically derived dose at which 50% of the individuals will be expected to die. For inhalation toxicity, air concentrations are used for exposure values. Thus, the LC50 (Lethal Concentration 50%) is used.
The units of LD50 and LC50 are listed as follows:
It shall be noted that LD50/LC50 from acute toxicity studies are mainly used for GHS acute toxicity classification, qualitative risk assessment and dose selection for repeated dose toxicity studies. They cannot be used to derive No-observed-adverse-effect-level (NOAEL).
LD50 and LC50 values are used to describe the relative acute toxicity of a chemical substance. The table below shows GHS classification criteria for acute toxicity. Acute toxicity category 1 represents the most severe toxicity.
You have learned the definition of acute toxicity, dose descriptor for acute toxicity (LD50 and LC50), GHS classification criteria for acute toxicity and testing guidelines.