7.3.1 Under the occupational Safety Act(Arbeitsicherheitsgesetz) occupational safety specialists and medical personnel must be appointed to cover certain workplaces. The exact threshold of staff numbers above which coverage must be provided and the time to be provided by these personnel is set by the BGs in their accident prevention regulations. Small firms are largely exempt from any obligation, but the exact requirements vary between sectors of employment and depend on the level of risk. The threshold generally lies between 20 and 50 workers.