Which statement accurately describes NOAEL and LOAEL in risk assessment?

• A. NOAEL is the highest exposure level at which no adverse effects are observed; LOAEL is the lowest exposure level that produces an adverse effect; they anchor reference doses and safety factors.
• B. NOAEL is the lowest exposure level that produces an adverse effect; LOAEL is the highest exposure level with no adverse effects.
• C. NOAEL and LOAEL refer to acute toxicity data only.
• D. NOAEL/LOAEL are used only for inhalation exposures.

Answer: (A)