On September 21, 2003, a violent explosion destroyed an underground distillation tower at the Isotec chemical manufacturing plant in Miami Township, Ohio, injuring one worker. The explosion ruptured a carbon monoxide gas pipe and led to a precautionary evacuation of about 2000 residents. The Isotec facility manufactures rare forms of oxygen and nitrogen, known as stable isotopes, which are used in research and medicine.

KEY ISSUES:
• PROCESS HAZARDS ANALYSIS
• INCIDENT INVESTIGATION
• LAND USE MANAGEMENT
• EMERGENCY RESPONSE

ROOT CAUSES:
1. Although Isotec and Sigma-Aldrich PHA records acknowledged the explosive potential of the NO system, there was no written documentation that action had been taken to minimize this potential.
2. Although Isotec experienced two previous NO distillation unit failures involving the detonation of liquid nitric oxide, the investigation records were incomplete. There was no record of the cause of the incidents and no documentation of corrective actions to prevent recurrence.
3. Neither the township zoning process nor the township and city permit approval processes adequately considered the hazards of preexisting industrial chemicals. Likewise, neither authority prescribed steps for addressing potential public consequences from the accidental release of chemicals.
4. A number of residents were not informed of the evacuation in a timely manner; others received no notification. Information was sometimes inconsistent or incomplete, causing confusion among evacuees

Image Credit: CSB