Which term describes a material that exerts little systemic toxic action or that reacts on contact?

• A. A material that exerts little systemic toxic action on contact
• B. A substance that causes mucous membrane irritation
• C. A material that exerts little systemic toxic action or that reacts on contact
• D. A substance that triggers immune responses

Answer: (C)

When thinking about how harmful a material could be, the important idea is how it could affect the body. A material described as having little systemic toxic action means it won’t cause toxic effects that travel through the bloodstream to organs. If it also may react on contact, that adds another way the material can cause immediate effects, but not through systemic toxicity. Putting those ideas together gives a description of a low-hazard material—that is, it has minimal overall toxic risk and may only react when touched.

That makes the term describing a material with both of these characteristics the best fit. The other options point to different hazard types—an irritant that affects mucous membranes, or a substance that triggers immune responses. The complete, nuanced phrasing that covers both low systemic toxicity and potential on-contact reaction is why this choice is the most accurate.