Laser Safety Guide

Safety Procedures

Class IV Lasers

The same requirements as for Class IIIB lasers shall be followed. In addition, the following safeguards are required:

• A total hazards review shall be conducted before a high power laser is used. This shall include evaluation of Nominal Hazard Zones (NHZ), measurements (if deemed necessary and other such analytical techniques.
  
  
• Devices shall be located in an area designated specifically for laser operations (laser controlled area). Access during operation must require authorization of the person responsible for the area. In conditions where the beam path is not completely enclosed, access shall be limited.
  
  
• An entryway control shall be used. This may include:
  
  
  • A non defeatable entryway interlock at the doorway, or
    
    
  • A defeatable entryway interlock at the doorway; or
    
    
  • Procedural entryway controls including a warning light immediately outside the room. One form of such a warning light could indicate conditions of enabled laser (high voltage on), laser on (beam on) and area clear (no high voltage or beam on).
    
    Such measures shall permit rapid egress by the laser personnel at all times and admittance to the area under emergency conditions.
    
    
• A control-disconnect switch or equivalent device shall be available near the exit for deactivating the laser.
  
  
• A notice outside the area shall indicate the meaning of the blinking light.
  
  
• Care must be taken to insure that the hands, arms, or other parts of the body do not intersect the beam.
  
  
• The system must have provision(s) for quickly disengaging the laser power source from the electrical main during emergency.
  
  
• The beam shall be terminated by a highly absorbent beam trap of fire resistant material.
  
  
• For infrared lasers, since the radiation is invisible, areas which are exposed to reflections of the beam shall be protected by fully enclosing the beam and target area.
  
  
• Ultraviolet laser beam radiation shall require a beam shield which attenuates the radiation to acceptable levels.
  
  
• A countdown procedure shall be used to signify the firing of single pulse laser types (eg.: Q-switch) to ensure all present are aware of the time of the operation.
  
  
• The use of laser protective eyewear is mandatory with Class IV lasers. Protective eyewear shall be fabricated of plastic or glass absorption filters appropriate for the laser. All laser protective eyewear shall be clearly labeled with optical density values and wavelengths for which protection is afforded.