Researchers and practitioners within safety critical industries seek to avoid personal harm to employees, and costly accidents to equipment, by preventing unsafe behaviours and incidents from occurring. Their actions and investigations are most effective before these occur and thus focused on understanding and developing tools to predict safety incidents. Such tools that predict incidents are lead indicators. The focus of this thesis is on further developing lead indicator safety climate measurement tools. These assess the degree to which employees believe there is enough value placed on safety in their workplace which in turn influences their likelihood of performing safe behaviours.