A review of the accidental release analysis procedure for the Clean Air Act Section 112(r)

As a result of the 1990 Clean Air Act Amendment, the US Environmental Protection Agency (EPA) is in the process of developing a chemical accident prevention program, which is covered under Section 112(r)(7). The EPA finalized the threshold quantities for the compounds listed in the 112(r)(7)(A) in January 1994. The proposed risk management program (RMP), 112(r)(7)(B), received over 1,000 comments from industries and the general public. The RMP rule proposed by the EPA is fundamentally based on the Process Safety Management (PSM) standard implemented by the Occupational Safety Health Administration (OSHA). The PSM was promulgated in May 1992. Many of the facilities subject to the OSHA PSM standard have developed certain programs to comply with the rule. The major difference between the EPA RMP and the OSHA PSM is the off-site hazard risk assessment (consequence analysis) required by EPA. As a result of this additional requirement, most of the comments received by the EPA for the proposed RMP rule concern the worst case release scenario defined for the hazard risk assessment, which may have a significant impact on the operations and future planning for all the facilities subject to this rule. This paper reviews major concerns involved in the consequencemore » analysis of accidental releases. Several well-established models are reviewed in terms of their applicability for different release scenarios.« less