What is indicated by an oral LD50 between 50 and 500mg/kg?

An oral LD50 value, which stands for "lethal dose for 50% of the population," measures the toxicity of a substance. When the LD50 falls between 50 and 500 mg/kg, it signifies that the pesticide is of moderate toxicity.

In toxicological terms, values lower than 50 mg/kg indicate high toxicity, where relatively small amounts can be lethal, while values above 500 mg/kg suggest lower toxicity. Therefore, a pesticide with an LD50 between 50 and 500 mg/kg is recognized as having a significant level of toxicity, but it does not pose as high a risk to individuals as substances with lower LD50 values. This is an essential consideration in pesticide application and safety protocols, as it helps ensure that appropriate precautions are taken when handling, applying, or disposing of the chemical.

The other options misrepresent the toxicity levels associated with the LD50 range provided. For instance, a highly toxic classification would require a lower LD50, while non-toxic substances would present much higher values, and "environmentally friendly" is not directly linked to toxicity levels in this context.