Pennsylvania Code
Title 25 - ENVIRONMENTAL PROTECTION
Part I - Department of Environmental Protection
Subpart D - Environmental Health and Safety
Article V - Radiological Health
Chapter 227a - RADIATION SAFETY REQUIREMENTS FOR NON-HEALING ARTS RADIATION-PRODUCING DEVICES
Subchapter B - GENERAL TECHNICAL REQUIREMENTS
Section 227a.13 - Radiation source housing

(a) Interlock. When the X-ray tube housing is the primary shielding for the X-ray tube and is intended to be opened for normal use or maintenance, the housing must be equipped with an interlock that shuts off the high voltage to the X-ray tube if the housing is opened.

(b) Radiation emission limit. Except as specified elsewhere in this chapter, each X-ray tube housing must be constructed so that, with all shutters closed, the leakage radiation measured at 5 centimeters from the X-ray tube housing surface does not exceed 2.5 mrem (0.025 mSv) per hour. This limit must be met at the maximum tube rating.