Lethal concentration
As lethal concentration (engl. Lethal concentration abbreviated as LC , often having a number additive, for example, LC 50 ) is in the environment ( water , soil or respiratory air ) located and effective concentration of a chemical substance referred to, the one within a defined period for defined percentage of a certain type of living being is fatal.
The mean lethal concentration, the LC 50 value, is often given to describe the hazard potential of a substance .
determination
To determine the acute inhalation toxicity , the rat is preferred as the test animal . The substance to be tested is absorbed via the airways . As a rule, a test duration of 24 hours is not exceeded.
In the field of aquatic toxicology, the acute lethal toxicity is usually determined on zebrafish (“ fish test ”), where the duration of action is usually 96 hours.
The LC 50 value is determined on earthworms for terrestrial toxicity determinations.
The unit of the LC values varies depending on the medium from mg · l −1 (for solutions in water) to mg · m −3 (substances in soil or gases in air).
Warfare agents
For gaseous warfare agents , the specification of the so-called "Haber's lethality product" LCt 50 is common (corresponds to Haber's rule ). This is the concentration of warfare agents in milligrams per cubic meter of air multiplied by the exposure time in minutes (unit: mg · m −3 ⋅min). The LCt 50 value describes the inhaled dose of warfare agent, which leads to death in half of the exposed persons.
literature
- Entry on LC. In: Römpp Online . Georg Thieme Verlag, accessed on September 5, 2014.
- OECD : Test No. 403: Acute Inhalation Toxicity , OECD Guidelines for the Testing of Chemicals, Section 4, OECD Publishing, 2009, doi : 10.1787 / 9789264070608-en .
- OECD: Test No. 203: Fish, Acute Toxicity Test , OECD Guidelines for the Testing of Chemicals, Section 2, OECD Publishing, 1992, doi : 10.1787 / 9789264069961-en .