What does NOHD stand for in laser safety terms?

What does NOHD stand for in laser safety terms?

• A. The distance to the laser source
• B. The distance along the beam beyond which exposure won't exceed MPE
• C. The distance between worker and wall
• D. The distance to emergency exit

Answer: (B)

NOHD, or nominal ocular hazard distance, marks the boundary along the laser beam where eye exposure changes from potentially hazardous to not exceeding the maximum permissible exposure (MPE) for the given wavelength and exposure time. In other words, beyond this distance the eye is unlikely to receive dangerous levels of laser radiation; within it, there is a potential hazard. This concept is used to define safe zones and inform protective measures. It isn’t simply the distance to the laser source, nor the distance to a wall or an emergency exit.

NOHD, or nominal ocular hazard distance, marks the boundary along the laser beam where eye exposure changes from potentially hazardous to not exceeding the maximum permissible exposure (MPE) for the given wavelength and exposure time. In other words, beyond this distance the eye is unlikely to receive dangerous levels of laser radiation; within it, there is a potential hazard. This concept is used to define safe zones and inform protective measures. It isn’t simply the distance to the laser source, nor the distance to a wall or an emergency exit.