1. (a) Warnings. Each x-ray system must:

   1. (1) have a warning light labeled "X-RAY ON", or words having similar intent, located near any switch that turns on an x-ray tube and which lights up only when the tube is energized; and

   2. (2) be labeled with a sign or signs bearing the radiation symbol and the following words or words having similar intent:

      1. (A) "CAUTION - HIGH INTENSITY X-RAY BEAM" on the x-ray source housing if the source housing is visible and accessible without the use of tools; and
      2. (B) "CAUTION RADIATION - THIS EQUIPMENT PRODUCES RADIATION WHEN ENERGIZED" near any switch that energizes a x-ray tube.

2. (b) X-ray tube housings.

   1. (1) Unused ports on x-ray tube housings must be secured in the closed position to prevent unintentional opening.
   2. (2) Each x-ray tube housing must be constructed so that when all shutters are closed the leakage radiation measured at a distance of 5 centimeters from the housing's surface is not capable of producing a dose in excess of 2.5 millirems in one hour at any specified tube rating.
3. (c) Caution signs, labels and signals; control device testing. Caution signs, labels and signals and control device testing are subject to the requirements of Subchapter 20.3.

Added at 17 Ok Reg 1136, eff 6-1-00