What is the federal annual dose limit for the extremities?

• A. 5 rem/yr
• B. 0.5 rem/yr
• C. 50 rem/yr
• D. 15 rem/yr

Answer: (C)

Different parts of the body have different annual exposure limits to reflect how sensitive they are to radiation and how shielding affects them. For the extremities—hands, feet, fingers, toes, and skin—the federal annual occupational dose limit is 50 rem per year, which is about 0.5 Sv. This higher limit makes sense because these areas are less radiosensitive than the whole body and are often better protected through gloves and practical shielding, while still being important to monitor to prevent localized harm.

In contrast, the whole-body limit is lower at 5 rem per year, since the entire body’s sensitivity is greater; the lens of the eye has a limit of 15 rem per year, reflecting its particular vulnerability to cataracts. Therefore, 50 rem per year is the appropriate limit for the extremities.