Evaluation of the OECD “Fish Prolonged Toxicity Study at Least 14 Days”

The Organization for Economic Cooperation and Development "Fish Prolonged Toxicity Study at Least 14 Days" test (OECD, 1981) determines the LC50 at fixed time intervals and establishes whether a lethal threshold concentration (LTC) exists. The lethal threshold concentration is the level of the toxicant which is lethal to 50 percent of individuals exposed for periods sufficiently long that the acute lethal action has ceased. The test can be run batchwise (renewal of the test solutions every 24 hours) or preferably using a flow-through system. The test period is usually from 14 to 28 days.