Accident: DPC Enterprises Glendale Chlorine Release
Location: Location: Glendale, AZ
Accident Occured On: 11/17/2003 | Final Report Released On: 02/28/2007
Accident Type: Release
Investigation Status: The CSB's final report was issued at a news conference in Glendale on February 28, 2007.
On November 17, 2003, there was a release of chlorine gas from the DPC Enterprises chlorine repackaging facility in Glendale, Arizona, near Phoenix. Fourteen people, including ten police officers, required treatment for chlorine exposure. The release occurred when chlorine vapors from a rail car unloading operation escaped from a system designed to recapture the material, known as a scrubber. Owing to the exhaustion of absorbent chemicals in the scrubber, chlorine gas was released.
Clarify the chemistry involved in over-chlorination incidents so that "Chlorine Scrubbing Systems, Pamphlet 89," and other pertinent publications: -Ensure that the recommended practices and safeguards prevent, mitigate, and control hazardous releases due to bleach decomposition. -Provide sufficient detail on the safety and environmental consequences of over-chlorination to enable companies to provide emergency responders with information on the potential characteristics of over-chlorination events, and on the best means of mitigating the bleach decomposition reaction following a release.
Establish and implement DPC corporate engineering standards that include adequate layers of protection on chlorine scrubbers at DPC facilities, including: -additional interlocks and shutdowns, such as automatically stopping chlorine flow to the scrubber upon oxidation-reduction potential alarm; -mitigation measures, such as systems to automatically add caustic to over-chlorinated scrubbers, or back-up scrubbing capability to treat emissions from over-chlorinated scrubbers; -increases in the final caustic concentration in the scrubbers to eight percent or higher to provide a substantial safety margin against over-chlorination; and -use of the site's continuous bleach manufacturing system to convert scrubber solution to saleable bleach.
Revise scrubber SOPs to include: -clearly described operating limits and warnings about the consequences of exceeding those limits, and -the safety and environmental hazards associated with scrubber over-chlorination.
Train employees on the revised SOPs and include a test to verify understanding. Periodically review operator understanding of and conformance to the scrubber SOPs.
Include scrubber operation in facility PHAs. Ensure that they: -include lessons learned from this incident and other DPC scrubber incidents, as well as industry experience with over-chlorination, and -consider off-site consequences when evaluating the adequacy of existing safeguards.
Use a qualified, independent auditor to evaluate DPC's PSM and RMP programs against best practices. Implement audit recommendations in a timely manner at all DPC chlorine repackaging sites.
Implement a recognized safety management system, including third party verification and certification, to achieve documented continuous improvement in safety performance at Glendale and the other DPC chlorine repackaging sites.
Work with the Glendale Police Department to integrate them into the incident command structure during hazardous material incidents, and address communications issues, such as radio interoperability, to ensure the timely transmission of critical safety information to responding officers.
Conduct hazardous materials exercises with the Glendale Police Department to identify and resolve police/fire integration issues. Coordinate exercise planning with the Arizona Division of Emergency Management Exercise Officer and with the Maricopa County LEPC. Schedule periodic hazardous materials incident drills to ensure safe and effective responses to future hazardous materials incidents.
Work with the Glendale Fire Department to integrate the Glendale Police Department into the command structure during hazardous material incidents, and address communications issues, such as radio interoperability, to ensure the timely transmission of critical safety information to responding officers.
Ensure that police officers responding to hazardous material incidents are briefed on specific incident conditions, and are equipped with and trained on the proper use, capabilities, and limitations of appropriate protective equipment.
Ensure that police officers receive hazardous materials - operations level training, and annual hazardous materials and air purifying respirator (APR) refresher training.
Conduct exercises with the Glendale Fire Department to identify and resolve police/fire integration issues. Coordinate exercise planning with the Arizona Division of Emergency Management Exercise Officer and with the Maricopa County LEPC. Schedule periodic hazardous materials incident drills to ensure safe and effective responses to future hazardous materials incidents.
Revise DPC's permitted operating conditions to specify a minimum scrubber caustic concentration of 8 percent or more, as determined by laboratory measurement, with measurements taken daily and upon completion of each scrubber batch.