Which oral LD50 value indicates the least toxic pesticide?

The oral LD50 (lethal dose for 50% of the population) value is a common measure used to assess the toxicity of substances, including pesticides. It indicates the dose required to kill half of a test population, often expressed in milligrams of substance per kilogram of body weight (mg/kg).

A higher LD50 value means that a larger amount of the substance is needed to achieve lethality, thus indicating lower toxicity. Therefore, the oral LD50 value of 6200 mg/kg signifies that it would take a much larger dose of this pesticide to reach a toxic level compared to those with lower LD50 values. This makes it the least toxic option among the ones provided.

In contrast, lower oral LD50 values, such as 27 mg/kg and 320 mg/kg, indicate higher toxicity, as smaller amounts of these substances can lead to lethal effects in organisms. A value of 585 mg/kg also reflects a higher toxicity level than 6200 mg/kg, emphasizing the relationship between LD50 values and the relative safety of a pesticide.