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DPC Enterprises Festus Chlorine Release

Overview

On August 14, 2002, a 1-inch chlorine transfer hose ruptured during a railroad tank car unloading operation at the DPC Enterprises chlorine repackaging facility near Festus, Missouri. The rupture released 48,000 pounds of chlorine over about 3 hours. Sixty-six people sought medical evaluation.

Incident Snapshot

Field Value
Facility / Company DPC Enterprises, L.P.
Location Festus, MO
Incident Date 08/14/2002
Investigation Status The final report on this investigation was approved May 1, 2003.
Accident Type Chlorine release during rail car unloading operation
Final Report Release Date 05/01/2003

What Happened

  • At about 6:30 am on August 14, 2002, DPC packagers, a truck driver, and the operations manager started chlorine filling and container preparation operations for the day.
  • Around 9:00 am, the repackaging system was placed on standby and the employees took their morning break.
  • Around 9:20 am, a 1-inch chlorine transfer hose used in a railroad tank car unloading operation catastrophically ruptured at tank car station #3.
  • Employees outside heard a loud pop and observed a continuous release of chlorine.
  • The leak activated an area chlorine detection monitor audio alarm.
  • The operations manager pushed the ESD button as he exited in an attempt to manually shut off the chlorine release.
  • Although both the automatic and manual ESD mechanisms were activated, several critical ESD valves failed to close and the release continued unabated.
  • At about 9:27 am, the DPC operations manager called 9-1-1 to report the chlorine release.
  • The Jefferson County R-7 volunteer fire department arrived on scene within about 10 minutes.
  • The release continued for nearly 3 hours until HAZMAT personnel closed the tank car valves.
  • Around noon, HAZMAT personnel and a DPC employee entered the release area and closed the liquid and vapor valves on the tank car.
  • The release stopped when valve C was closed.
  • Around 5:00 pm, the Jefferson County R-7 fire department lifted the evacuation order and reopened Highway 61.

Facility and Process Context

  • The facility repackages bulk dry liquid chlorine into 1-ton containers and 150-pound cylinders for commercial, industrial, and municipal use.
  • DPC Festus is located on an 8-acre site in the Plattin Creek Valley of Jefferson County at 1785 Highway 61.
  • The chlorine repackaging process is a one-shift operation, typically running from 6:00 am to 4:00 pm, Monday through Friday.
  • At the end of the day, a packager manually closes all tank car valves, directs residual chlorine in the piping system to the bleach production process, pulls a vacuum, leaves the system under negative pressure, and presses the ESD button to close all ESD valves.
  • The chlorine transfer hoses remain connected to the tank car overnight.
  • Leak testing by spraying small amounts of ammonia solution around possible leak points is performed prior to startup the next day.
  • Blue Fountain residential mobile home park, consisting of about 100 homes, is directly adjacent to the southwest.
  • Several residential areas, businesses, Jefferson Memorial Hospital system facilities, St. Pius High School, and Festus–Crystal City Airport are located within a 1-mile radius of the facility.

Consequences

  • Fatalities: None reported.
  • Injuries: Sixty-three people from the surrounding community sought medical evaluation for respiratory distress, and three were admitted for overnight observation. Three DPC workers received minor skin exposure to chlorine during cleanup activities. Eight persons were administered oxygen.
  • Environmental release: 48,000 pounds of chlorine was released over a 3-hour period.
  • Facility damage: None reported.
  • Operational impact: Traffic was halted on Interstate 55 for about 1.5 hours. The community was advised to shelter-in-place for 4 hours. Highway 61 was shut down in both directions.

Key Findings

Immediate Causes

  • The chlorine transfer hose ruptured about 3.5 feet from its connection to the tank car.
  • The hose was constructed with 316L stainless steel structural braiding, which was inappropriate for chlorine transfer.
  • Corrosion of the 316L braid layer weakened the structural integrity of the hose.
  • Normal operating pressure, in combination with repetitive bending forces, caused the hose to rupture.
  • Corrosion products impeded motion of the ESD valves, preventing them from closing.
  • The tank car excess flow valves remained open during the release.

Contributing Factors

  • The hose identification system of chlorine transfer hose manufacturers was inadequate to provide continuous positive identification of similar-looking structural braiding materials of construction such as Hastelloy C and stainless steel.
  • The DPC mechanical integrity program failed to detect corrosion in the chlorine transfer and pad air systems before it caused operational and safety problems.
  • The community notification system was inefficient, resulting in additional exposure to neighboring residents and businesses.
  • DPC emergency preparedness planning was deficient.
  • Jefferson County community emergency preparedness planning was inadequate for an incident of this magnitude.
  • Wet chlorine caused excessive corrosion of the chlorine unloading piping and pad air piping systems, which prevented the ESD valves from closing properly.
  • Potential sources of water included atmospheric moisture from inadequate capping of hoses and tank car piping assemblies, and moisture from the pad air supply system.

Organizational and Systemic Factors

  • The DPC quality assurance management system did not have adequate provisions to ensure that chlorine transfer hoses met required specifications prior to installation and use.
  • Branham Corporation did not have a quality assurance management system to ensure that fabricated hose complied with customer specifications or that its certification of materials specifications was correct.
  • The DPC testing and inspection program did not include procedures to ensure that the process emergency shutdown system would operate as designed.
  • Routine inspection, testing, and maintenance checks at DPC Festus were inadequate and poorly supervised.
  • During the transition after the operations manager resigned in July 2001, there were periods with no management supervision of day-to-day operations, including inspections.
  • The new manager was inexperienced in chlorine repackaging operations.
  • DPC provided training on chlorine repackaging, but it was inadequate for safety responsibilities and did not sufficiently cover preventive maintenance and inspection.
  • DPC training on mechanical integrity focused on how to and when to, not on the consequences of inadequate inspection or warning signals of equipment failure.
  • The DPC emergency response plan did not contain adequate guidelines or mechanisms to ensure prompt community notification of an incident.
  • The DPC emergency response plan did not clearly specify the responsibilities of response team members during a release.
  • The DPC emergency response plan did not contain timetables or schedules for initial or annual employee refresher training in accordance with HAZWOPER requirements.
  • The DPC emergency response plan had no built-in audit procedures.
  • The DPC emergency response plan made no provisions for drilling emergency response personnel on various levels of response.
  • The DPC emergency response plan did not have clear guidelines on emergency equipment testing and inspection.
  • The DPC emergency response plan included no guidelines for planning post-incident cleanup of hazardous materials.
  • Coordination between local emergency planning and response entities and DPC was insufficient to ensure timely community notification and mitigation of the release.
  • The Jefferson County emergency plan had not been updated since 1996.
  • Its hazardous materials incident component was too general.
  • It did not include methods and schedules for testing with all participating local authorities.
  • It had not been tested for public evacuation or shelter-in-place responses.

Failed Safeguards or Barrier Breakdowns

  • The chlorine transfer hose was not the specified material of construction.
  • The DPC standard operating procedures did not require packagers to verify that the indicators showed actual closure of the ESD valves.
  • The ESD system was not designed to provide a signal of actual valve closure.
  • The tank car excess flow valves remained open during the release.
  • The equipment was not adequately maintained or organized inside the repackaging building.
  • DPC had no community sirens or other community-wide alert systems to notify neighboring residents and businesses of a release.
  • No procedures for evacuation or shelter-in-place had been given in advance to residents or businesses.
  • The chlorine repackaging system piping had not been measured for wall thickness, nor internally inspected.
  • The ESD valves were not visually inspected or tested for ease of closure prior to the incident.
  • The DPC emergency response plan contained no documentation, schedules, or procedures to indicate that equipment testing and inspection regulatory requirements were fulfilled.
  • The DPC emergency response plan included no guidelines for post-incident cleanup of hazardous materials.
  • The operators wore level C PPE, which was inadequate for the job.

Recommendations

  1. 2002-04-I-MO-R1 — Recipient: DPC Enterprises L.P., Festus Site — Status: Not specified — Develop and implement a quality assurance management system, such as positive materials identification, to confirm that chlorine transfer hoses (CTH) are of the appropriate materials of construction.
  2. 2002-04-I-MO-R2 — Recipient: DPC Enterprises L.P., Festus Site — Status: Not specified — Implement procedures and practices to ensure the emergency shutdown (ESD) system operates properly. Include procedures to verify that the ESD valves will close to shut down the flow of chlorine.
  3. 2002-04-I-MO-R3 — Recipient: DPC Enterprises L.P., Festus Site — Status: Not specified — Revise the preventive maintenance and inspection program for the chlorine transfer system to address moisture-related corrosion. Evaluate and correct any problems associated with corrosion that could potentially lead to chlorine transfer and safety system failure.
  4. 2002-04-I-MO-R4 — Recipient: DPC Enterprises L.P., Festus Site — Status: Not specified — Require periodic inspection of the above critical safety systems by the operations or facility manager.
  5. 2002-04-I-MO-R5 — Recipient: DPC Enterprises L.P., Festus Site — Status: Not specified — Develop procedures to clearly designate the roles and responsibilities of facility emergency response personnel, including post-incident remediation.
  6. 2002-04-I-MO-R6 — Recipient: DPC Enterprises L.P., Festus Site — Status: Not specified — Develop and implement a timetable for drills to test emergency response personnel on various levels of response, including a large uncontrolled release that could affect the public. Coordinate these drills with local emergency response authorities. Provide a copy of the revised Emergency Response Plan to the local emergency planning committee, and review the plan with the committee and the local fire department. Work with these authorities to implement an improved community emergency notification system.
  7. 2002-04-I-MO-R7 — Recipient: DPC Enterprises L.P., Festus Site — Status: Not specified — Improve accessibility of equipment required for emergency response, considering likely response scenarios.
  8. 2002-04-I-MO-R8 — Recipient: DX Distribution Group (corporate owner of DPC Enterprises, L.P.) — Status: Not specified — In light of the findings of this report, conduct periodic audits of the safety management systems involved in this incident, such as mechanical integrity, emergency response, and material quality assurance. Ensure that the audit recommendations are tracked and implemented. Share findings and recommendations with the work force at your repackaging facilities.
  9. 2002-04-I-MO-R9 — Recipient: DX Distribution Group (corporate owner of DPC Enterprises, L.P.) — Status: Not specified — To improve supervision of day-to-day operations, revise your corporate safety management-training program on chlorine repackaging operations. Emphasize safety critical systems, including verification of safety system performance.
  10. 2002-04-I-MO-R10 — Recipient: DX Distribution Group (corporate owner of DPC Enterprises, L.P.) — Status: Not specified — Communicate the findings and recommendations of this report to all DPC facilities.
  11. 2002-04-I-MO-R11 — Recipient: Branham Corporation — Status: Not specified — Implement a materials verification procedure to improve quality assurance during chlorine transfer hose fabrication and shipment, such that hoses shipped to customers are readily identifiable and meet required specifications.
  12. 2002-04-I-MO-R12 — Recipient: Jefferson County Emergency Management Agency (EMA) — Status: Not specified — Work with DPC to implement a community notification system that will immediately alert neighboring residents and businesses of a chemical release.
  13. 2002-04-I-MO-R13 — Recipient: Jefferson County Emergency Management Agency (EMA) — Status: Not specified — Work with DPC, local emergency planning and response authorities in Jefferson and adjacent counties, the City of Festus, and Crystal City to improve overall response and mitigation time.
  14. 2002-04-I-MO-R14 — Recipient: Jefferson County Emergency Management Agency (EMA) — Status: Not specified — Communicate the findings and recommendations of this report to your membership.
  15. 2002-04-I-MO-R15 — Recipient: Missouri State Emergency Response Commission — Status: Not specified — Communicate the findings and recommendations of this report to local emergency planning committees, emergency management agencies, and local fire departments.
  16. 2002-04-I-MO-R16 — Recipient: Missouri Department of Natural Resources (MDNR) — Status: Not specified — In collaboration with appropriate agencies, hold a community meeting in Festus, Missouri, to hear concerns raised by local citizens affected by the DPC incident and to respond to issues raised by the community.
  17. 2002-04-I-MO-R17 — Recipient: Agency for Toxic Substances and Disease Registry (ATSDR) — Status: Not specified — Work with State and local agencies to address concerns about the long-term health effects of the chlorine release in Festus, Missouri, and communicate your findings to the community.
  18. 2002-04-I-MO-R18 — Recipient: The Chlorine Institute, Inc. — Status: Not specified — Work with the Association of Hose and Accessories Distributors (NAHAD) and chlorine hose manufacturers, such as Crane-Resistoflex, to develop and implement a recommended practice requiring continuous positive identification throughout the supply chain, from manufacturing to the end user of the product.
  19. 2002-04-I-MO-R19 — Recipient: The Chlorine Institute, Inc. — Status: Not specified — Develop recommended practices to address moisture in dry chlorine piping systems. Include information on suggested material specifications, prevention and corrective measures, and adverse consequences, particularly for emergency shutdown systems.
  20. 2002-04-I-MO-R20 — Recipient: The Chlorine Institute, Inc. — Status: Not specified — Develop recommended practices for testing, inspection, and preventative maintenance of ESD systems for bulk transfer of chlorine.
  21. 2002-04-I-MO-R21 — Recipient: The Chlorine Institute, Inc. — Status: Not specified — Communicate the findings and recommendations of this report to your membership.
  22. 2002-04-I-MO-R22 — Recipient: National Association of Hose and Accessories Distributors (NAHAD) — Status: Not specified — Work with The Chlorine Institute and chlorine hose manufacturers, such as Crane-Resistoflex, to develop and implement a recommended practice requiring continuous positive identification throughout the supply chain, from manufacturing to the end user of the product.
  23. 2002-04-I-MO-R23 — Recipient: National Association of Hose and Accessories Distributors (NAHAD) — Status: Not specified — Communicate the findings and recommendations of this report to your membership.
  24. 2002-04-I-MO-R24 — Recipient: National Association of Chemical Distributors (NACD) — Status: Not specified — Communicate the findings and recommendations of this report to your membership.

Key Engineering Lessons

  • Chlorine transfer hoses must be positively identified as the correct material of construction before installation and use. Visual inspection alone is not sufficient when similar-looking braiding materials can be confused.
  • Emergency shutdown systems should be verified to confirm actual valve closure, not merely activation of the shutdown signal.
  • Moisture-related corrosion in chlorine transfer and pad air systems can impair safety-critical equipment and should be addressed through preventive maintenance and inspection.
  • Mechanical integrity programs need inspection and testing methods capable of detecting corrosion and other degradation before they lead to transfer-system or safety-system failure.
  • Community notification and emergency response planning must be coordinated with local authorities and tested for large uncontrolled releases that could affect the public.

Source Notes

  • Priority 1 final report was used to resolve conflicts where it differed from supporting documents.
  • The final report states 66 people sought medical evaluation; supporting documents also reference 63 community members and 3 workers with minor exposure, which were retained in the injuries summary.
  • The transcript contains some inconsistent or amended recommendation wording; the final report recommendation text was used where available.
  • All facts were limited to the provided source extracts; no external information was added.

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