According to DGUV publication 201-056 (formerly BGI 5164), access routes that are within 2 metres of the falling edge (where the outer edge of the structure is at least 3 metres above ground level), are considered to be in the fall danger zone. The technical rules for workplaces ASR A2.1 agree with this, stating: "Workplaces and accesses that are at least 2.0 m from the falling edge are outside the fall danger zone."
Individuals are only allowed to work within 2 metres of the falling edge, if they are accordingly secured against falls. As a rule, this is achieved through personal fall protection equipment (PPE) which trained employees use to attach themselves to locally-installed anchorage devices. The mandatory kit always includes a safety harness and a suitable connector. If there are no permanently-installed anchorage points or lifeline systems on the building structure, a mobile anchorage device can also be used on a flat roof surface. Such anchors are generally weighed down with weights, e.g. concrete slabs or synthetic weights. However, if the danger zone needs to be accessed regularly, a collective protection measure is required. This can be achieved, for example, by installing a guard rail system.