If a chemical is poisonous, what does this indicate?

• A. Harmless
• B. Non-toxic
• C. Poisonous
• D. Inert

Answer: (C)

Poisonous describes an inherent potential to cause harm to living organisms. If a chemical is poisonous, it can produce adverse effects—illness or death—when it is absorbed, inhaled, or ingested, depending on the dose and exposure route. The key point is that toxicity is about hazard, and the level of danger depends on how much exposure occurs and how the substance enters the body. This is why such a chemical requires careful handling, proper PPE, and controls to prevent exposure. It is not harmless, not non-toxic, and not inert, because those terms would imply little to no risk, whereas poisonous indicates a real potential for harm.