161. The primary radiation employed in fluoroscopy must be attenuated by a screen with a lead-equivalent of at least 1.5 mm in the case of x-ray machines operating at a maximum potential of 100 kV. For each additional kilovolt, a 0.01 mm lead-equivalent is added.
Exposure must be interrupted automatically when the screen is removed from the useful beam.
R.R.Q., 1981, c. P-35, r. 1, s. 161.