The Control of Major Accident Hazards Regulations 2015 provide the principal framework for controlling major accident risks involving dangerous substances in Great Britain. They apply where specified substances are present, or are anticipated to be present, at or above the relevant qualifying quantities. All COMAH operators must take all measures necessary to prevent major accidents and limit their consequences for people and the environment. Additional duties apply according to whether an establishment is lower-tier or upper-tier. This practical one-day course provides an introductory overview of the COMAH regime and the principal requirements applying at each tier, including regulatory expectations, Competent Authority oversight and the types of arrangements operators use to support compliance. The emphasis will be tailored to delegates from establishments below COMAH thresholds intending to enter scope, as well as lower-tier and upper-tier establishments. Delegates will examine dangerous-substance thresholds and aggregation, Major Accident Prevention Policies, Safety Management Systems, upper-tier safety reports, emergency preparedness and Competent Authority expectations. Worked examples and industry case studies will relate these requirements to delegates’ own establishments and responsibilities.