The purpose of illumination of high risk task areas is to increase the safety of persons involved in potentially dangerous processes or situations and to allow safe and correct completion or interruption of activities in such areas. In high risk task areas, the operating level of illuminance at the reference plane should not be lower than 10% of the normal illuminance required for given activities, however no less than 15 lx. The stroboscopic effect must be eliminated. The uniformity of illuminance in a high risk task area should not exceed 10:1.
The minimum duration of emergency lighting should be as long as the safety hazards exist.
High risk task area lighting should ensure full and continuous illuminance required at once or within 0.5 s, depending on the application.
The luminance of each colour area of a safety sign should be at least 2 cd/m2 in all viewing directions which are important for safety.