Which factor most influences respirator selection for radiological work?

• A. Inhalation hazard and assigned protection factor
• B. Time of day and laboratory coat color
• C. The isotope with no concentration considerations
• D. The wearer's height and shoe size

Answer: (A)

The factor that matters most is how dangerous the inhalation exposure could be and how much a respirator can reduce that exposure, expressed as the assigned protection factor (APF). In radiological work, airborne radioactive material poses a potential inhalation hazard, and the amount of protection you need depends on how high the air concentration could be and how long you’ll be exposed. The APF tells you how much the respirator lowers the inhaled contaminant when worn correctly; choosing a respirator means selecting one with an APF high enough to bring the expected exposure below safe limits. Fit and use matter too, because a great APF does not help if the respirator doesn’t seal properly or isn’t worn as intended. The other factors listed don’t influence protection in the same way: time of day or coat color are irrelevant; the isotope concept is not about ignoring concentration in practice; and body measurements don’t affect respirator performance.