Air-purifying respirators are ideal for use in a limited oxygen environment or one that is immediately dangerous to health or life.

• A. True
• B. False
• C. Only in oxygen-rich environments
• D. Only when there is adequate ventilation

Answer: (B)

Air-purifying respirators remove contaminants from the air you breathe but do not supply oxygen. In environments with limited oxygen or that are immediately dangerous to life or health, this is not safe because the atmosphere may be oxygen-deficient even if the air looks and smells normal. APRs rely on the surrounding air’s oxygen to function, so if oxygen levels drop, a wearer can become hypoxic regardless of filter efficiency. In such conditions you need a respirator that provides breathing air from a safe source, such as a supplied-air respirator or a self-contained breathing apparatus. Adequate ventilation can lower contaminant levels, but it doesn’t address dangerous oxygen depletion, so APRs aren’t appropriate in those scenarios. Hence, the statement is false.