- The installations must not present an accident risk to workers and must be installed in such a way as to prevent all dazzle.
- Proper diffusion of light must be ensured and shadow zones avoided.
- Good visibility of surfaces and colours must be ensured, especially in the case of what are known as safety colours.
- The general lighting must not be too weak in relation to the local lighting
The lighting intensity must be measured during activities at the same workplace. There are tables of recommended light intensity, depending on the particular type of activity pursued; in general, however, a nominal light intensity of at least 500 Lux is recommended for workplaces which are permanently occupied and situated indoors.