The continued rise of non-standard forms of employment, including increased use of subcontractors, has focused industry and research attention on how to manage the Occupational Health and Safety (OHS) of subcontractor employees. Existing measures to mitigate OHS risk appear to be less effective in the case of subcontractor employees as they are shaped by principal contractors and regulatory bodies in isolation to the realities of the non-standard nature of subcontractor work. From this point of view, in order to successfully manage subcontractor OHS risk, it is necessary to explore OHS risk as a perceived uncertainty that is constructed by the various stakeholders ((1) Principal Contractor and Subcontractor management, (2) Regulator, and (3) Subcontractor employees) based on their understanding of subcontractor work. The thesis is structured as a series of three studies, each addressing a different stakeholder point of view. The first study utilises focus groups to understand the reasons behind subcontractor OHS risk from the viewpoint of the managements of principal contractors and subcontractors. The second study utilises accident case studies to explore the viewpoint of the regulator. The third study is a six-month ethnography in an Australian utility organisation where data was collected through participant observations and 17 semi structured interviews with both the principal contractor and subcontractor employees to identify how the precarious nature of subcontractor work impacts their perception of OHS risk. A key question throughout this work was why do some subcontractors experience significantly higher OHS risk than others? To explain this, the thesis introduces the notion of ‘standing’. Standing is the informal hierarchical position of a subcontractor employee. This includes concepts previously discussed in the literature such as employee safety voice, injury reporting, and authority to stop work, but also factors such as job autonomy, and invoked paternalism from Principal Contractor/Client co-workers. The thesis concludes that standing contributes to subcontractor OHS risk through its connection to the precariousness of subcontractor work. The results have further implications towards the design of more well-rounded solutions to improve subcontractor OHS that take the nature of the work into consideration.