Six case studies of fires or explosions involving air pollution control (APC) systems are reviewed in this paper. These case studies have been generalized from actual accident investigations performed by the authors.

The case studies cover the APC technologies of thermal oxidation, catalytic oxidation, gas scrubbers, adsorption, and condensation. Each of the technologies was used to control emissions of volatile organic compounds (VOCs). The accidents encompass a broad range of industries, ignition sources, and circumstances. The causal factors for these accidents are compared with applicable safety guidelines and standards to show how safeguards could have prevented or mitigated these accidents.

The common theme that emerges from these accident investigations is that APC systems should not be specified and installed strictly by intuition or experience, but rather through careful engineering design. The key findings of this study are:

  • Characterize the waste stream to be treated.

  • Conduct a process hazard analysis for each APC system, with particular emphasis on fire and explosion hazards.

  • Design the APC system using good engineering practices.

  • Operate the APC system within its design specifications.

  • Periodically verify that the APC system performance satisfies its technical and regulatory objectives.

  • Perform maintenance activities in accordance with manufacturer's recommendations.

Each of the accidents was the direct result of the omission of one or more of these basic tenets. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2005