This research project investigated OHS/WHS hazards impacting on EHOs in Australia, the United States and New Zealand, and outcomes will used to inform potential OHS/WHS guidelines to manage workplace hazards that EHOs are exposed to. This mixed methods research adopted a methodological triangulation design, allowing the researcher to use different methods to approach the same research topic. Environmental Health Officers (EHOs) in all three countries reported that the major OHS/WHS hazards were work related psychological stress, musculoskeletal demands, exposure to chemical and biological agents, driving incidents and workplace violence.