Which statement best describes the relationship between hazard and exposure?

• A. Hazard is the exposure
• B. Hazard is the potential to cause adverse effects
• C. Hazard is the exposure to a hazard
• D. Exposure determines hazard

Answer: (B)

Hazard is the inherent potential to cause harm, not the actual contact. Exposure is the actual contact with that hazard under specific conditions (dose, duration, route). So hazard describes what could happen, while exposure describes what is actually happening to someone. This makes the statement that hazard is the potential to cause adverse effects the most accurate. The idea that hazard is exposure mixes up the two concepts, and saying exposure determines hazard or that hazard is exposure to a hazard is circular. If there’s no exposure, there’s no illness risk—even with hazardous properties present, risk depends on both hazard and exposure.