The maximum exposure rate limits for radiographic exposure devices, storage containers and source changers are 2 millisieverts (200 millirem) per hour at any exterior surface, and 0.1 millisieverts (10 millirem) per hour at 1 meter (approximately 3 feet) from any exterior surface with the sealed source in the shielded position.
10-144 C.M.R. ch. 220, § E-C-6