Good lighting is important at the workplace in order to concentrate over longer periods, but also to work safely. The European standard EN 12464 specifies the lighting requirements that must be complied with: the main parameters are, in addition to illuminance,
- luminance distribution,
- danger of glare,
- light direction,
- light colour and colour rendering,
- flicker, and
- daylight.
The importance of daylight was specifically emphasised in the updated DIN EN 12464-1 from 2011. In addition, it is repeatedly pointed out that lighting should be controllable or adjustable.
The Committee on Workplaces supervised by the German Ministry of Labour and Social Affairs also reflects the state of scientific knowledge for occupational safety and health in the setting up and operating of workplaces:
- The mean illuminance in the surrounding area of a workstation with 300lx illuminance must be at least 200lx.
- For workstations illuminated with 500lx or more, the mean illuminance in the surrounding area must be at least 300lx.
- Illuminances above 500lx in workstation areas may require a higher mean illuminance in the surrounding areas.
- The minimum illuminance in the surrounding area must not fall below 0.5 times the mean illuminance of the surrounding area.
For light visual tasks, sufficient
visual performance is achieved with low illuminance levels, whereas complex visual tasks need high illuminance levels. For example, 20 lux is a bottom limit at which people's facial features can only just be distinguished.