The Clean Air Act requires EPA to promulgate regulations to prevent accidental releases of regulated substances and reduce the severity of those releases that do occur. EPA is promulgating rules that apply to all stationary sources with processes that contain more than a threshold quantity of a regulated substance. Processes will be divided into three categories based on: the potential for offsite consequences associated with a worst-case accidental release; accident history; or compliance with the prevention requirements under OSHA's Process Safety Management Standard. Processes that have no potential impact on the public in the case of an accidental release will have minimal requirements. For other processes, sources will implement a risk management program that includes more detailed requirements for hazard assessment, prevention, and emergency response. Processes in industry categories with a history of accidental releases and processes already complying with OSHA's Process Safety Management Standard will be subject to a prevention program that is identical to parallel elements of the OSHA Standard. All other processes will be subject to streamlined prevention requirements. All sources must prepare a risk management plan based on the risk management programs established at the source. The source must submit the plan to a central point specified by EPA; the plan will be available to state and local governments and the public. These regulations will encourage sources to reduce the probability of accidental releases of substances that have the potential to cause immediate harm to public health and the environment and will stimulate the dialogue between industry and the public to improve accident prevention and emergency response practices.