A barrier is a collective protection measure which warns people that they are entering a fall danger zone. As long as they do not cross it, there is no chance of them falling.
Barriers are used when work has to be carried out on a roof surface or when an access route is adjacent to a fall danger zone. As long as there are no components around that are incapable of bearing loads (for example, non-fall-through-resistent domed rooflights, strip lighting and light panels), it is not usually necessary to use a special fall arrest system. Barriers are used to prevent workers from inadvertently entering a danger zone. Workers can dispense with the use of PPE equipment as long as the danger zones are clearly marked and they only work outside these danger zones.
It may, however, be necessary to use PPE equipment when originally installing a barrier.
According to DGUV Information 201-054 , a barrier can be a guard rail, a chain or a rope - but on no account can you simply close off the section using warning tape as this can be blown into the fall danger zone by a strong wind. This would leave the fall danger zone unmarked. The barrier should be designed in a bright signal colour. An additional sign may be used to indicate the danger zone.
Barriers can be used on roofs with a maximum roof pitch of 22.5° and must be installed at least 2 m away from the falling edge. If a roof is generally accessed by individuals who do not have to enter the fall danger zone to carry out their tasks, a barrier is a simple and cheap method of installing a preventive fall protection system. However, should it be necessary to work in the fall danger zone, a simple barrier is definitely not enough. In this case, a suitable fall arrest system must be used.