In the standard hazard assessment framework, what is the correct sequence of components?

• A. Hazard identification, dose-response assessment, exposure assessment, risk characterization.
• B. Exposure assessment, hazard identification, risk characterization, dose-response.
• C. Risk characterization, hazard identification, exposure assessment, dose-response.
• D. Dose-response assessment, hazard identification, risk characterization, exposure.

Answer: (A)

The main idea is the logical, stepwise flow of a hazard-based risk assessment: identify what could cause harm, quantify how dose relates to effect, measure exposure, then synthesize into overall risk. First, hazard identification asks whether a chemical has the potential to cause adverse health effects and what endpoints are relevant. Next, dose–response assessment characterizes how the probability or severity of those effects changes with dose, establishing curves and points of departure. Then exposure assessment estimates how much, how long, and through which routes people are exposed, providing the context needed to assess actual risk. Finally, risk characterization combines hazard information with exposure data to describe the overall risk and its uncertainties, guiding decisions. The other sequences don’t fit because you can’t meaningfully characterize risk or quantify exposure without knowing what hazards exist and how dose relates to effects.