(1) A safety device which prevents the entry of any portion of an individual's body into the primary x-ray beam path or which causes the beam to be shut off upon entry into its path shall be provided on all open-beam configurations.
(a) A registrant may apply to the department for an exemption from this requirement for a safety device. Such application shall include:
(i) a description of the various safety devices that have been evaluated;
(ii) the reason each of these devices cannot be used; and
(iii) a description of the alternative methods that will be employed to minimize the possibility of an accidental exposure, including procedures to assure that operators and others in the area will be informed of the absence of safety devices.
(2) Analytical x-ray equipment shall be equipped with the following warning devices:
(a) Open-beam configurations shall be provided with a readily discernible warning device which shall indicate:
(i) whether the x-ray tube is on or off, and which shall be located near the radiation source housing, if the primary beam is controlled in this manner; or
(ii) whether the shutter is open or closed, and which shall be located near each port on the radiation source housing, if the primary beam is controlled in this manner;
(b) Warning devices shall be labeled so that their purpose is easily identified. On equipment installed after July 1, 1980, warning devices shall have fail-safe characteristics.
(3) Unused ports on radiation source housings shall be secured in the closed position in a manner which will prevent casual opening.
(4) All analytical x-ray equipment shall be labeled with a readily discernible sign or signs bearing the radiation symbol and the words:
(a) "CAUTION--HIGH INTENSITY X-RAY BEAM", or words having a similar intent, on the x-ray source housing; and
(b) "CAUTION--RADIATION--THIS EQUIPMENT PRODUCES RADIATION WHEN ENERGIZED", or words having a similar intent, near any switch that energizes an x-ray tube if the radiation source is an x-ray tube; or
(c) "CAUTION--RADIOACTIVE MATERIAL", or words having a similar intent, on the source housing if the radiation source is a radionuclide.
(5) On open-beam configurations installed after July 1, 1980, each port on the radiation source housing shall be equipped with a shutter that cannot be opened unless a collimator or a coupling has been connected to the port.
(6) An easily visible warning light labeled with the words "X-RAY ON", or words having a similar intent, shall be located near any switch that energizes an x-ray tube and shall be illuminated only when the tube is energized; or in the case of a radioactive source, near any switch that opens a housing shutter, and shall be illuminated only when the shutter is open. On equipment installed after July 1, 1980, warning lights shall have fail-safe characteristics.
(7) Each x-ray tube housing shall be so constructed that, with all shutters closed, the leakage radiation measured at a distance of 5 cm from its surface is not capable of producing a dose in excess of 2.5 mrem in 1 hour at any specified tube rating; and if radioactive sources are used, corresponding dose limits shall not exceed 2 mR per hour.
(8) Each x-ray generator shall be supplied with a protective cabinet which limits leakage radiation measured at a distance of 5 cm from its surface such that it is not capable of producing a dose in excess of 0.25 mrem in 1 hour.