A concentration lethal to 50% of the population is known as

A concentration lethal to 50% of the population is known as

• A. LD50
• B. LC50
• C. TD50
• D. ED50

Answer: (B)

LC50 refers to the lethal concentration of a substance that kills 50% of a test population over a defined exposure period. This is the appropriate term when the measurement is a concentration in the exposure medium (such as air or water) rather than a dose per body weight. In industrial hygiene and toxicology, LC50 is used for inhalation or aquatic exposures and is typically reported in units like mg/m3 or mg/L. It differs from LD50, which is the lethal dose per body weight (mg/kg); TD50, the dose causing toxic effects (not necessarily death) in 50%; and ED50, the dose producing a defined effect in 50%. Because the question specifies concentration, LC50 is the best fit.

LC50 refers to the lethal concentration of a substance that kills 50% of a test population over a defined exposure period. This is the appropriate term when the measurement is a concentration in the exposure medium (such as air or water) rather than a dose per body weight. In industrial hygiene and toxicology, LC50 is used for inhalation or aquatic exposures and is typically reported in units like mg/m3 or mg/L. It differs from LD50, which is the lethal dose per body weight (mg/kg); TD50, the dose causing toxic effects (not necessarily death) in 50%; and ED50, the dose producing a defined effect in 50%. Because the question specifies concentration, LC50 is the best fit.