Which statement best defines a poison?

Which statement best defines a poison?

• A. A substance that is toxic at extremely low levels
• B. A substance that irritates the skin on contact
• C. A substance that smells pleasant
• D. A substance that glows in the dark

Answer: (A)

The main idea is that a poison is defined by its ability to cause harmful health effects at very small amounts. Toxicity at extremely low levels means that only a tiny exposure can produce adverse effects, which is what makes a substance a poison. Irritants cause irritation but may not produce toxic effects at low doses, so that isn’t the best definition for poison. Smelling pleasant and glowing in the dark have nothing to do with a substance’s toxic potential. So the statement that a substance is toxic at extremely low levels best captures what makes something a poison.

The main idea is that a poison is defined by its ability to cause harmful health effects at very small amounts. Toxicity at extremely low levels means that only a tiny exposure can produce adverse effects, which is what makes a substance a poison. Irritants cause irritation but may not produce toxic effects at low doses, so that isn’t the best definition for poison. Smelling pleasant and glowing in the dark have nothing to do with a substance’s toxic potential. So the statement that a substance is toxic at extremely low levels best captures what makes something a poison.