The radioactive Yellow-II label is used on packages which have a maximum dose rate of .5 mSv/hr (50 mR/hr) on any exterior surface.

The radioactive Yellow-III label is used on packages with a maximum dose rate of 2 mSv/hr (200 mR/hr) on their exterior surfaces.

The labels are white except for the upper half of the radioactive Yellow-II and radioactive Yellow-III labels which are yellow. The printing and the radiation symbol are black except for the "I," "II," or "III" numerals which must be red.