66.4.1 radioactive material is used, the area shall be labeled with a radiation sign on with installing radiation originates. For people who work or live in the area, clearly visible radiation.
66.4.1 the areas where the radioactive material must be labeled with the radiation than in the original source of radiation. So people who work in, or visible radiation.
66.4.1 area with the use of radioactive materials will be labeled with mark radiation into the installation source of radiation. For people who work or live in the radiation apparent.