Service Personnel

Service personnel are particularly susceptible to ocular injury since they often gain access to collimated laser beams from the laser cavity itself, or by opening up the beam – delivery optics and gaining access to collimated laser beams prior to the beam focusing optics or fiber-optic beam-delivery system. Once the laser beam leaves the delivery system and comes rapidly into a focus, it then diverges again, or if emerging from a fiber, it also rapidly diverges. Because of the nature of flashlamps, the light emitted from IPL devices rapidly diverge. The zone where the beam is concentrated to a level sufficient to pose severe hazard to the eyes or skin (the Nominal Hazard Zone or NHZ), is normally a limited zone of less than 1-2 m near the beam focal point. However, a collimated laser beam, as the raw beam for most laser cavities, or a specular reflection from a turning mirror or Brewster window in the laser console may be emitted from the laser cabinet (protective housing) when the service person gains access. Several serious eye injuries have occurred to service personnel exposed to secondary, collimated, and invisible 1064 nm Nd:YAG laser beams when the service personnel gained access to the laser cavity. According to ANSI Z136.3, a “temporary controlled area” must be established when such potential risks occur during servicing.