Laser Radiation and Other Hazards
Laser radiations can be hazardous, especially for eyes and skin. An incoming laser radiation in the eye can be focused by the eye's lens to a small spot on the retina, where it can cause serious permanent damage. The potential damages caused by an incident laser radiation on the eye or the skin depend on the laser characteristics. The damages can result from both thermal and photochemical effects. However, the high power output emitted by any industrial laser processing systems makes them inherently hazardous tools that requires proper laser safety measures to protect the users.
Not only does the laser radiation is potentially dangerous, the electrical or chemical risks must be considered because lasers use high electric voltages and can produce toxic fumes.
International Safety Standards
Government regulations define required safety measures for people who may be exposed to lasers. For the US, the American National Standards Institute Standard ANSI Z136.1: American Standard for Safe Use of Lasers and ANSI Z136.9: American National Standard for Safe Use of Lasers in Manufacturing Environment is applied. In Canada and the European Community, eye protection requirements are specified in the European standard EN 207 and IEC 60825-1.
Laser systems are categorized according to their ability to produce damage to exposed eye and skin. From class 1 (no hazard during normal use) to class 4 (severe hazard for eyes and skin). One thing to keep in mind is that all industrial lasers for material processing are classified as Class 4. However, using suitable enclosures and methods allows to turn them into Class 1 laser system.
The responsibility of ensuing laser safety according to ANSI Z136.1 including filing the CDRH reports (if necessary) falls entirely on the end user. All workers who are in contact or need to manipulate class 4 lasers have to get proper training on laser safety and should examined by an ophthalmologist each 3 years.
Technical precautions are frequently used for laser safety, some are listed below:
- The use of protective goggles, adequate for the laser used.
- Full or partial enclosing of the laser with absorbing housing materials and interlocks that switch off lasers if protective box is opened.
- Signs and confinement measures preventing people from entering dangerous areas.