Risk assessment methodologies have been developed to provide a structured approach to the analysis of safety hazards. By their nature, they allow a systematic assessment of the management options to minimize the risk to workers and the public. This approach is also used to assess the risks to the environment by determining the impacts both of planned activities (e.g., emissions and discharges) and unplanned events (e.g., chemical spills). In this way, the risks from each stage of a project development can be assessed and systems for their management put in place.