What effect does a lower LD50 value have on toxicity?

A lower LD50 value indicates higher toxicity because LD50, or lethal dose for 50% of the test population, refers to the amount of a substance required to kill half of a test group, typically in laboratory settings. The lower the LD50, the smaller the dose needed to achieve lethal effects. This relationship demonstrates that substances with a low LD50 are more toxic, as they can cause harm or death at lower exposure levels.

For instance, if a substance has an LD50 value of 10 mg/kg and another has an LD50 value of 300 mg/kg, the substance with the 10 mg/kg value is much more toxic to the organism, requiring significantly less of the substance to be lethal. Thus, understanding the implications of LD50 values is critical in assessing and managing risks associated with toxic substances.