Each area or room containing a radiation-producing device where an individual may receive 2 mrem (0.02 mSv) in any 1 hour or 100 mrem (1 mSv) per year shall be conspicuously posted with a sign or signs bearing the radiation symbol and "CAUTION RADIATION-THIS EQUIPMENT PRODUCES RADIATION WHEN ENERGIZED," or words having a similar intent.
25 Pa. Code § 227a.16