If the radiation-producing device is not in a restricted area as defined in 10 CFR 20.1003 (relating to definitions), the operator shall control access to the radiation-producing device at all times during operation. The following apply:

1. (1) Radiation areas must be conspicuously identified. The following apply:

   1. (i) The radiation source must be within a conspicuous perimeter, for instance, a rope, tape or other barrier, that identifies the area in which radiation levels could result in an individual receiving a dose equivalent in excess of 0.005 rem (0.05 mSv) in 1 hour.
   2. (ii) The area described in subparagraph (i) must be suitably posted with ‘‘CAUTION—RADIATION AREA’’ signs.
   3. (iii) The operator shall ensure that no one is inside and that no one enters the radiation area during operation of the radiation-producing device.

2. (2) High radiation areas must be conspicuously identified. The following apply:

   1. (i) The radiation source must be within a conspicuous perimeter, for instance, a rope, tape or other barrier, that identifies the area in which radiation levels from radiation sources external to the body could result in an individual receiving a dose equivalent in excess of 0.1 rem (1 mSv) in 1 hour.
   2. (ii) The area described in subparagraph (i) must be suitably posted with ‘‘CAUTION—HIGH RADIATION AREA’’ signs.
   3. (iii) The operator shall ensure that no one is inside or enters the high radiation area during operation of the radiation-producing device.
3. (3) The operator shall perform a visual check of the controlled area to ensure that it is free of unauthorized personnel immediately prior to activating or exposing the radiation source.