Which LD50 value indicates the highest level of toxicity?

The LD50 value indicates the median lethal dose of a substance, representing the amount of a chemical required to kill 50% of a test population, typically measured in milligrams of substance per kilogram of body weight (mg/kg). A lower LD50 value signifies a higher level of toxicity because it means that a smaller amount of the substance is lethal to half of the test subjects.

In the context of the given values, 1 mg/kg is significantly lower than 100 mg/kg or 10 mg/kg, indicating that only a small dose is necessary to achieve lethal effects. Therefore, the lowest LD50 value of 1 mg/kg demonstrates the greatest toxicity, confirming that the substance with this value is more toxic compared to those with higher LD50 values.

The other LD50 values represent increasing levels of chemical required to produce lethal effects, thereby indicating lower toxicity levels relative to the 1 mg/kg value.