【Basic Knowledge of Occupational Health】: The Lethal Concentration for 50% of the Population, LC50
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This post was last edited by slll611 on 2016-5-18 21:41. Do you know what LC50 is? I know about this thing, but I’ve forgotten where; I can’t find the source. It’s available on Baidu, but since it’s basic knowledge, its authenticity should be ensured. Finally found an authoritative one. Or you know which standard provides an exact definition. GBZ/T224-2010 \"Terminology for Occupational Health\" defines it as the concentration of a chemical substance under certain experimental conditions that results in a 50% mortality rate among the test animals. In English, it is referred to as median lethal concentration. The unit for LC50 is mg/L; the lower the value of LC50, the stronger the toxicity of the poison ； Conversely, the higher the LC50 value, the lower the toxicity of the toxin.
GBZ/T224-2010 \"Terminology for Occupational Health\" defines it as the concentration of a chemical substance under certain experimental conditions that results in a 50% mortality rate among the test animals. In English, it is referred to as median lethal concentration. The unit for LC50 is mg/L; the lower the value of LC50, the stronger the toxicity of the poison ； Conversely, the higher the LC50 value, the lower the toxicity of the toxin.
LC50: (Lethal Concentration 50, the concentration at which 50% of the target organisms are killed) refers to the concentration of the agent required to kill 50% of the target organisms. The international unit for this value is mg/L, while the unit commonly used in everyday life is PPm, which also represents 1/1,000,000. The lethal concentration for 50% of the population is an important parameter for measuring the toxicity of toxins present in water to aquatic animals, and the toxicity of toxins present in air to mammals and humans. The lethal effect of toxins is closely related to the exposure time of the animals being tested. If LC50 is used to indicate the acute toxicity of a toxin in water to aquatic organisms, the exposure time must be specified before the LC50 value, such as 24-hour LC50, 48-hour LC50, and 96-hour LC50, etc. If LC50 is used to represent the acute toxicity of air toxins to mammals, it generally refers to the test results obtained 2 hours or 4 hours after the test animals inhale the toxin; the inhalation time need not be specified, although it can sometimes be indicated as well. For example, LCt50 refers to the product of the concentration that causes half of the animals to die and the inhalation time, with time (t) generally expressed in minutes.