Feb 1, 2005 · LC 50 is the concentration of a substance that is lethal to 50 percent of the organisms in a toxicity test. LC 50 can be determined for any exposure time, but the most common exposure period is 96 hours.

Mar 23, 2016 · Acute toxicity to fish (96hrs, LC50 in mg/l): The acute toxicity is expressed as the median lethal concentration (LC 50) that is the concentration in water which kills 50% of a test batch of fish within a continuous period of exposure which is usually 96hrs.

QSARs include acute and chronic toxicity endpoints for (1) fish, (2) aquatic invertebrates (Daphnia), and (3) aquatic plants (green algae). These organisms are surrogate species representing the aquatic food web. Endpoints for acute and chronic toxicity to these three organisms form the standard EPA New Chemicals Program ecotoxicity profile.

The fish are exposed to the test substance preferably for a period of 96 hours. Mortalities are recorded at 24, 48, 72 and 96 hours and the concentrations which kill 50 per cent of the fish (LC50) are determined where possible.

Definitive testing may be waived if limit testing with at least 30 organisms shows LC50 levels to be greater than 1,000 mg/L based on 100 percent active ingredients (AI), or the limits of water solubility or dispersibility.

The current experiment was performed with the aim to determine the median lethal concentration (LC 50) of endosulfan, heptachlor and dieldrin to African catfish (Clarias gariepinus); their behavioral abnormalities and histopathological alterations in several vital organs.

LC 50 c a l c u l a t i o n s h e l p pre d ic t to x icity Tuesday, 1 February 2005 By C l au d e E . Boyd , Ph . D. Safe concentration of a toxicant is called the maximum allowable toxicant concentration Aquaculturists sometimes ar e confronted with the t oxicity of natural or man-made substances t o sh, shrimp, or

Sep 22, 2019 · This dataset was used to develop quantitative regression QSAR models to predict acute aquatic toxicity towards the fish Pimephales promelas (fathead minnow) on a set of 908 chemicals. LC50 data, which is the concentration that causes death in 50% of test fish over a test duration of 96 hours, was used as model response.

Jun 27, 2024 · The median lethal concentration, or LC 50, is the concentration of a toxicant given at one time that causes the death of 50% of a population of test organisms. The LC 50 is a standardized approach for assessing the short-term (acute) …

LC50 – the concentration of a substance that is lethal to 50% of the organisms exposed to it in a toxicity test – is a useful tool because it can predict the effects of a po-tential toxin in...