A laser is used in welding and cutting processes to provide a concentrated heat source that quickly heats metals to extremely high temperatures. Laser welding and cutting are often used in high volume applications.
During the process, a laser uses electricity to create a coherent, parallel light that directly focuses on the material being cut or welded to melt, burn, or vaporize it. A laser light may be different colors of the visible light spectrum or invisible when the light is ultraviolet or infrared. Lasers used for welding and cutting may be infrared and the beam may be invisible making it difficult for operators to take proper precautions.
A lot of the radiation that strikes the workpiece is reflected into the surrounding environment emitting fumes, gases, and smoke that can contain a variety of oxides. Laser welding and cutting fumes and gases can be made up of particles so small they aren't visible to the human eye, presenting serious health and safety risks.
The overall health hazard risk of laser welding and cutting is based on how long machine operators are exposed to these fumes, dusts, and gases, how much space is in the working area, what materials are being cut, and the quality of protection that is being implemented.
Radiation - Visible and invisible light radiation is produced during welding or cutting processes. Because of the interaction with the workpiece, a high concentration of dangerous blue light and ultraviolet radiation develop. This type of radiation can severely burn eyes and skin quickly and permanently.
Fire - This style of laser system produces a very small spot size with high energy creating a fire risk if a laser beam hits flammable material. It is critical that flammables are kept away from welding or cutting areas. Since reflected radiation has the capability to start fires in unexpected places, anything flammable in the work area must be covered and protected.
Fumes and Mists - While lasers vaporize metals, fumes and mists are produced creating respiratory hazards. Because fumes and mists are not often visible it is crucial to use adequate ventilation or a filtration system to prevent serious health hazards.
Mechanical - The optical device on the robotic arm or beam manipulator being used can malfunction and send the laser beam in unintended directions. It is essential that the work area is shielded in compliance with standards for the specific laser type and class.
Electric Shock - Because most lasers require a large amount of electrical power in welding and cutting processes, electrical hazards are present. There are the general hazards associated with any electrical industrial power source and unique electrical hazards common to lasers and the individual application. Commonly, the best source for safety information is provided in the instruction manual from the manufacturer of the laser system.
Eye and Skin Damage - In many situations, special laser eye protective devices are required. According to the ANSI Z136.1 standard, this eyewear must be labeled with both the optical density (protective factor) and wavelength(s) for which the protection is afforded. The protective eyewear must be compatible with the laser systems manufacturer’s specifications to ensure that the eyewear is suitable. In addition to the primary hazard of the laser beam, there may be a considerable eye hazard from high levels of secondary radiation. The ANSI Z136.1 standard requires that the eyes be protected from this secondary radiation in addition to the primary laser beam. Any laser eyewear, plain or prescription, must be labeled with the wavelength(s) of protection and the optical density at that wavelength(s). In some laser systems, ultraviolet light may be leaked into the workplace. The eyewear should provide primary beam protection, secondary radiation protection, and also ultraviolet protection.