Laser Safety Program: Non-Beam Hazards

Electrocution is most likely to occur when the protective covers are removed or interlocks are defeated to allow access to active components during installation, maintenance, modification, or service of lasers or laser systems.

• Check for potential electrical problems during laser facility audits:
  • Make sure laser systems are installed according to manufacturer specifications, or as required on the National Electrical Code (NFPA 70E).
  • Check for uncovered or improperly insulated electrical terminals.
  • Be alert for hidden "power-up" warning lights.
  • Properly discharge and ground capacitors.
  • Ensure that all energy sources are disengaged or blocked and that electrical sources are de-energized and locked in the "off" position during work or repair. UC San Diego offers Lockout/ Blockout Training for employees.
  • Guard against excessive wires and cables on the floor creating fall or slip hazards.
  • Know where the closest Automated External Defibrillator (AED) is located and how to use it.
• Make sure personnel receive training about electrical hazards.
  • Require cardiopulmonary resuscitation (CPR) training for service personnel, researchers, and their assistants. UC San Diego offers Emergency Medical Training.
  • Encourage periodic refresher courses.
• Require at least 2 trained employees be present when work involves high voltage laser power supplies.

Recognize the fire hazard from Class 4 laser beams.

• Use flame resistant materials when:
  • Irradiances exceed 10 Watts cm^-2
  • Beam powers exceed 0.5 Watts
• Ensure personnel know what to do in case of fire.
  • Read If You Discover a Fire ...
  • How to Use a Fire Extinguisher

Prevent injury from explosion to the equipment operator and observers.

• Enclose high-pressure arc lamps, filament lamps, and capacitor banks in a housing that can withstand the maximum explosive pressure.
• Enclose or equivalently protect the laser target and elements of the optical train which may shatter during laser operation.
• Be aware of the possibility of explosive reactions from chemical laser reactants.

• Follow chemical safety practices described in the General Chemical Safety Guidelines.
  • Take special care when handling laser dyes and solvents, preparing solutions, and operating dye lasers. Certain dyes are highly toxic or carcinogenic.
  • Store laser dyes and solvents in proper secondary containers. Read Chemical Storage and Inventory Guidelines for more information.
  • Identify known and suspected human carcinogens and take appropriate precautions.
  • Read How to Handle Cryogenic Liquids, if applicable.
• Ensure Material Safety Data Sheets (MSDSs) are readily available for employees who work with or in the vicinity of hazardous chemicals.
• Be prepared for a chemical emergency.
  • See How to Handle Chemical Spills in Laboratories.
• Identify hazardous chemical waste and dispose of it properly.

• Follow the UC San Diego compressed gas guidelines for safe handling and storage. Read:
  • Compressed Gas Classification and Requirements Overview
  • Compressed Gas Use and Storage Guidelines

• Take precautions to eliminate or reduce optical radiation hazards:
  • Shield ultraviolet radiation emitted from a laser's discharge tubes and pumping lamps (i.e., not part of the primary laser beam).
    • Maintain personnel exposures within the threshold limit values specified by the American Conference of Governmental Industrial Hygienists (ACGIH).
  • Consider additional protection requirements for operators exposed to plasma emissions. Plasma emissions created during a laser-welding process may have sufficient ultraviolet or blue light content (1.8 to 5.5 µm) to raise concern for operators viewing a process on a long-term basis.
    • Recommended additional protection for plasma emission may include:
      • Distance
      • Shielding
      • Personal protection equipment

• Investigate and control the source and intensity of X-rays emanating from laser power supplies and components.
• Follow standards and guidelines from:
  •  UC San Diego Radiation Safety Manual (PDF)
  • American National Standard "General Safety Standard for Installations Using Non-Medical X-Ray and Sealed Gamma-Ray Sources, Energies up to 10 MeV," ANSI/ NBS Handbook 114

Potentially hazardous fumes and vapors may be produced by laser welding, cutting, and other laser-target interactions.

• Reduce or eliminate exposure to potentially hazardous fumes and vapors to levels below those used for non-laser conventional cutting (such as flame cutting and welding of the same material).
• Install adequate local exhaust ventilation.
  • Read Engineering Controls for Laboratory Safety and Chemical Fume Hoods Overview for more information about ventilation and exhaust systems used at UC San Diego.
• Learn how to access the UC San Diego Respiratory Protection Program if a respirator may be required to protect employee health.