Volatility refers to which property?

• A. Water solubility
• B. Soil binding
• C. Evaporation potential
• D. Photodegradation rate

Answer: (C)

Volatility is about how readily a chemical becomes a gas. It describes how easily a substance evaporates into the air from surfaces or soil. That’s why the property it reflects is evaporation potential—the tendency to vaporize and move into the air. When a chemical is highly volatile, more of it can evaporate during and after application, increasing the chances of off-target movement and inhalation exposure. The other properties describe different behaviors: water solubility is about dissolving in water, soil binding is how strongly it adheres to soil particles, and photodegradation rate is how quickly it breaks down under light. While those factors affect fate and transport in other ways, they don’t define volatility.