Toxicity is defined as the degree of which a substance can cause injury to biological tissue. Which option best matches this definition?

• A. Degree of which a substance can cause injury to biological tissue
• B. The speed at which a chemical evaporates
• C. The duration of a chemical's shelf life
• D. The rate at which a chemical reacts with water

Answer: (A)

Toxicity describes how harmful a substance can be to living tissue, which depends on the dose and exposure conditions. The choice that states the degree to which a substance can cause injury to biological tissue directly matches this idea, because it defines toxicity as the potential to cause damage to biological systems. In practice, toxicity isn’t about how quickly a chemical evaporates, how long its shelf life lasts, or how fast it reacts with water. Those properties describe volatility, stability, and reactivity, respectively, not the harm potential. So this option best reflects the concept of toxicity and is the correct choice for understanding harmful effects on biological tissue.