MEDIAN LETHAL DOSE Meaning and
Definition
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The median lethal dose (LD50), a term used primarily in toxicology, refers to the chemical or substance dose that is estimated to be lethal to 50% of the individuals or test subjects exposed to it. It is a measure of acute toxicity used to determine and compare the relative potency or danger of different substances. The LD50 is usually determined through laboratory experiments, typically conducted on laboratory animals.
The LD50 is expressed as the amount of substance administered per unit of body weight of the test subject, commonly milligrams of the substance per kilogram of body weight. The purpose is to establish a dose-response relationship, allowing for an assessment of the substance's lethal impact.
By administering varying doses to a test group of animals, ranging from low to high levels, researchers can observe the percentage of animals that survive at each dosage. The dose at which the survival rate hits precisely 50% marks the LD50. Calculating this value allows scientists to estimate the potential lethal dosage range for humans. The LD50 value is used in regulatory decisions and helps determine appropriate safety measures, such as dosage limits and warning labels, to protect human health and minimize the risk of exposure to dangerous substances.
