What is the recommended distance and angle to stand from the X-ray beam?

• A. 0.5-1 metre away at 0°
• B. 3 metres away at 180°
• C. 1.5-2 metres away at 90°-135°
• D. 0.3 metres away at 45°

Answer: (C)

The key to radiation protection during dental X-ray work is maximizing distance from the source and positioning yourself out of the path of the primary beam. The intensity of radiation drops quickly as you move away, following the inverse square law, so increasing distance substantially lowers your exposure.

Standing about 1.5 to 2 metres from the patient puts you well clear of the primary beam’s intensity. Positioning yourself at a side angle of roughly 90° to 135° relative to the beam means you’re not in the direct line of the beam and you avoid much of the scatter that travels forward from the patient. This combination—greater distance than closer standpoints and a side-on angle—provides the best protection for the operator.

Being much closer (for example around 0.3 to 1 metre) or aligning directly with the beam (0°) would expose you to far more radiation, and an angle like 45° doesn’t place you far enough to the side to minimize scatter exposure.