For the purposes of this chapter, the following definitions shall apply
1° Optical radiation: all electromagnetic radiation with a wavelength between 100 nanometres and 1 millimetre. The spectrum of optical radiation is subdivided into ultraviolet radiation, visible radiation and infrared radiation:
a) Ultraviolet radiation: optical radiation with a wavelength between 100 nanometres and 400 nanometres. The ultraviolet range is subdivided into UVA (315-400 nanometres), UVB (280-315 nanometres) and UVC (100-280 nanometres) radiation;
b) Visible radiation: optical radiation with a wavelength between 380 nanometres and 780 nanometres;
c) Infrared radiation: optical radiation with a wavelength between 780 nanometres and 1 millimetre. The infrared range is subdivided into IRA (780-1,400 nanometres), IRB (1,400-3,000 nanometres) and IRC (3,000 nanometres – 1 millimetre) radiation;
2° Laser (amplification of light by stimulated emission of radiation) : any device capable of producing or amplifying electromagnetic radiation of wavelengths corresponding to optical radiation, essentially by the process of controlled stimulated emission;
3° Laser radiation: optical radiation from a laser;
4° Incoherent radiation: all optical radiation other than laser radiation;
5° Exposure limit values: limit values for the level of exposure to optical radiation, based directly on proven health effects and biological considerations, compliance with which ensures that workers exposed to artificial sources of optical radiation are protected from any known harmful effects on health;
6° Irradiance (E) or power density: incident radiated power per unit area on a surface, expressed in watts per square metre (W. m – ²);
7° Irradiance (H): the integral of irradiance with respect to time, expressed in joules per square metre (J. m – ²);
8° Luminance (L): the energy flux or power per unit solid angle and per unit area, expressed in watts per square metre per steradian (W. m – ². sr – ¹);
9° Level: the combination of irradiance, energy exposure and radiance to which a worker is exposed.