In the building construction industry, the safety of workers has become a paramount concern. This is particularly so in the construction of multi-storey buildings where it has been acknowledged that a fall of greater than 1.8 metres can be fatal. On such sites, there may be many risks of falls, and one of these is the risk or a worker falling through a formwork penetration or cavity destined to become a column of the multi-storey building, and within which a prefabricated steel reinforcement cage is to be lowered prior to filling with concrete to create the column.

Conventionally, a formwork penetration is covered by a plywood board or the like, which is normally nailed down to the surrounding structure. A message is then spray painted onto the plywood board warning of the danger of a fall if the board is removed or excessive weight is applied thereon. A major risk of a fall arises when the plywood board is removed in order to lower a steel reinforcement cage within the formwork penetration, at which time there are numerous workers standing around the now uncovered and unprotected penetration trying to carefully manoeuvre the cage downwardly into position with the aid of a crane. With their attention fixed on the reinforcement cage, the workers may fail to notice that they are stepping dangerously close to the penetration and accidentally fall into it.

Research has indicated that the risk of a worker falling down a formwork penetration in a multi-storey building may be substantially reduced by providing a fall safety barrier that, when the penetration is not in use, is in a collapsed state for covering the penetration, and when the penetration is in use, is in an upright state for preventing workers stepping dangerously close to the penetration.