Since the invention of the laser in the 1960s and the emergence of high-power laser devices and supporting manufacturing systems in the 1970s, laser processing technology has developed laser welding, laser cutting, laser drilling, direct laser forming of metal parts, after decades of development There are dozens of industrial processing technologies such as laser engraving, laser marking, laser cladding, laser surface shaping, laser 3D printing, laser cleaning, laser scanning and measurement, as well as laser medical and beauty, laser lighting and other commercial applications. Compared with traditional processes and methods, lasers have brought about tremendous changes in product design, manufacturing processes and production concepts, and are triggering tremendous changes in processing and manufacturing and commercial fields. At the same time, the application of laser also generates some new dust, smoke, gas hazards and potential hazards such as laser burns and radiation, etc., collectively known as laser hazards, the safety countermeasures taken against laser hazards are called laser protection, this chapter And below only consider the hazards of laser radiation.
Laser radiation can cause damage to human eyes and skin, with the former having the most severe consequences. Because the human eye transmits and absorbs lasers of different wavelengths
Different wavelengths, different wavelengths of laser damage to human eyes are also different.
Laser radiation, even with very little energy, its energy density may be quite high, which will affect human health. Eye injuries caused by laser radiation mainly include photo-induced keratitis, corneal coagulation, carbonization and perforation, lens opacity, visual dysfunction 'flash blindness', and retinal coagulation, bleeding and bursting. Even more serious is that the eye damage caused by the laser is permanent and cannot be recovered or improved by treatment.
The skin damage caused by laser radiation mainly includes pigmentation, erythema and blisters. The degree of damage depends on the radiation dose, which is related to the output energy, working wavelength and working state of the laser, of which energy is the most important factor. Not only direct light, but also reflected light and diffuse light are harmful to human body and working environment.
The basis for taking protective measures against laser radiation is the laser safety protection standard. The general standards commonly used in the world mainly include the Chinese national standard GB 7247.1-2012, the International Electrotechnical Commission (IEC) standard IEC 60825, the EU standard EN60825 and the American National Standards Institute standard (ANSI-Z136.1). T 7247.14-2012, GJB 1762-1993, GB / T 18151-2008, EN 207 / EN 208, EN 12254: 2010, IEC 60825-4: 2006, ANSI-Z136.7, etc.
All laser safety standards divide the laser into several safety levels according to parameters such as output energy, operating wavelength, and pulse width. Divided by
It is the radiation limit directly related to the damage threshold. The expression methods and values ??of different standard irradiation limits are different.