Question

Which of the following compounds listed below has the lowest lethal dose, based on LD50, where the LD50 is based on oral or skin exposture by test animals?

A) Phenobarbital
B) Strychnine
C) Nicotine
D) PCBs

Answer 1

Strychnine has the lowest lethal dose (LD50) among the listed compounds, making it the most toxic.

Step-by-step explanation:

The LD50 is a standardized measure for expressing and comparing the toxicity of chemicals. The LD50 is the dose that kills half (50%) of the animals tested. In this case, we are comparing the LD50 values for different compounds based on oral or skin exposure. The higher the LD50 value, the lower the toxicity of the compound. Let's analyze the options:

• A) Phenobarbital: LD50 values range from 50 to 600 mg/kg, so it is not the compound with the lowest lethal dose.
• B) Strychnine: LD50 values range from 2 to 4 mg/kg, which is significantly lower than Phenobarbital. It is a highly toxic compound.
• C) Nicotine: LD50 values range from 3 to 12 mg/kg, making it more toxic than Strychnine and Phenobarbital.
• D) PCBs: There is no specific LD50 value provided for PCBs in the given information, so we cannot determine their toxicity level compared to the other compounds.

Based on the given information, Strychnine has the lowest lethal dose (LD50) among the listed compounds, making it the most toxic.