This a document which must accompany any filming and recce schedule.  This makes sure that the person responsible when on location has considered the safety of everyone involved in the filming from the contributor, the crew to the general public.  You have to think through the filming day and consider what the potential hazards are, what injury could result from this hazard and how the risk can be reduced or avoided.  You must be practical and realistic, the majority of injuries tend to come from trip hazards and manual handling kind of activities.