Skip to content

KMCO LLC Fatal Fire and Explosion

Overview

On April 2, 2019, a flammable isobutylene vapor cloud exploded at the KMCO, LLC facility in Crosby, Texas. The event fatally injured one KMCO employee and seriously injured two others. At least 28 other workers were injured. The CSB final report identified a brittle overload fracture of a cast iron y-strainer driven by internal pressure as the cause of the release.

Incident Snapshot

Field Value
Facility / Company KMCO, LLC
Location Crosby, TX
Incident Date 04/02/2019
Investigation Status The CSB released its final report on 12/21/23. A fire and explosion at the KMCO custom chemical processing and speciality chemical manufacturing facility caused one fatality and multiple injuries.
Accident Type Chemical Manufacturing - Fire and Explosion
Final Report Release Date 12/21/2023

What Happened

  • On the morning of April 2, 2019, KMCO’s operations staff were making a batch of sulfurized isobutylene.
  • Field Operator 1 and Board Operator 1 completed the isobutylene charge to the batch reactor that KMCO’s night shift operators had started.
  • Control system data showed that the isobutylene charge was completed at 6:25 a.m.
  • Shortly before 10:41 a.m., Field Operator 1 heard a loud “pop” sound followed by a loud whooshing noise similar to “an air hose coming off.”
  • Field Operator 1 told CSB investigators that a y-strainer failed.
  • A contract worker insulating tubing near the reactor heard the loud sound when the “line blew,” saw the vapor pouring into the area, and ran out of the unit.
  • Board Operator 1 identified the leak as isobutylene and announced: “Attention KMCO, evacuate the reaction area.”
  • Soon after 10:46 a.m., the isobutylene release stopped after Board Operator 1 closed a manual isolation valve in the unit.
  • The Shift Supervisor used the all-call feature on his radio to order an evacuation of the plant at about 10:47 a.m.
  • KMCO surveillance cameras visibly shook after 10:51 a.m., capturing the time of the explosion.
  • The explosion lifted the Shift Supervisor off the ground.
  • The first member of KMCO’s emergency response team (ERT) to put on their protective equipment and head toward the unit did so at about 10:54 a.m., about three minutes after the explosion.
  • Emergency responders transported Board Operator 1 and the Shift Supervisor by helicopter to a hospital in Houston.
  • KMCO conducted a headcount and found that one KMCO employee, Board Operator 2, was missing.
  • Emergency responders found Board Operator 2 deceased under debris near the entrance to the R2 Building.

Facility and Process Context

  • KMCO, LLC facility in Crosby, Texas, employed 164 people to manufacture specialty chemicals and operate its tolling facilities.
  • KMCO purchased the Crosby plant on July 1, 2012, and invested over $50 million in the facility.
  • KMCO built a blast-resistant control room in 2013 to improve safety.
  • At the time of the April 2, 2019, incident, only one of three buildings commonly referred to as control rooms was being used as a formal control room.
  • KMCO renamed the former Reaction 2 Control Room the R-II Motor Control building (“R2 Building”).
  • The R2 Building also housed the equipment needed to stop some of the equipment for Board Operator 2’s units.
  • A self-contained breathing apparatus (SCBA) was also located in the R2 Building.
  • KMCO planned to relocate useful equipment from the R2 Building into a new motor control center and then demolish the R2 Building.
  • KMCO’s decision to eliminate this building was based on safety concerns with the R2 Building’s type of construction and the proximity of this building to reactors, as well as more efficient operation.
  • KMCO used isobutylene as a raw material in its batch reaction process to manufacture sulfurized isobutylene lubrication additive products.
  • On the day of the incident, this reaction system was producing HiTEC® 3315, a lubrication additive.
  • KMCO’s isobutylene system included a storage tank, circulation pump, charge pump, piping, manual valves, automatic valves, and a pressure control valve.

Consequences

  • Fatalities:
  • 1 KMCO employee was fatally injured.
  • Board Operator 2 died from “sharp force injuries of the right upper extremity with transection of the right brachial artery and vein” resulting from an “accident”.
  • Injuries:
  • Board Operator 1 and the Shift Supervisor suffered serious burn injuries that resulted in inpatient hospitalization.
  • At least 28 other workers were injured, including five KMCO employees and 23 contract workers.
  • Environmental release:
  • More than 10,000 pounds of isobutylene were released during the incident.
  • About 10,000 pounds of isobutylene were released in 5 minutes and 25 seconds.
  • Facility damage:
  • Portions of the KMCO facility were substantially damaged from the explosion and subsequent fires.
  • The area of greatest explosion damage was the R2 Building.
  • One responder said, “Shrapnel. … There was nothing left of it. Wires, there was nothing there. There wasn’t a building there anymore.”
  • The y-strainer ruptured.
  • Operational impact:
  • KMCO filed for Chapter 7 Bankruptcy (liquidation) in May 2020.
  • The facility was sold to Altivia Oxide Chemicals, LLC.
  • KMCO is no longer in business.

Key Findings

Immediate Causes

  • The cause of the isobutylene release was a brittle overload fracture of the cast iron y-strainer driven by internal pressure.
  • The y-strainer was installed in a segment of the isobutylene piping that was not protected from the high-pressure conditions that developed within this equipment, most likely from liquid thermal expansion.
  • The isobutylene vapor cloud was most likely ignited by electrical equipment within a poorly sealed, nearby building.

Contributing Factors

  • KMCO’s hazard evaluation programs, including process hazard analysis, pre-startup safety review, and management of change, also contributed to the incident.
  • KMCO did not provide safety equipment that its workers could have used to remotely stop (isolate) the isobutylene release from a safe location, which contributed to the severity of the incident.
  • Deficiencies in KMCO’s emergency response system, including its procedures and training, also contributed to the severity of the incident by not effectively distinguishing which events its operators should handle from those incidents that the site’s emergency response team must respond to.
  • Because KMCO relied on its unit operators to take quick actions to stop chemical releases, workers who were in a safe location moved toward the flammable isobutylene vapor cloud, which put them in harm’s way.

Organizational and Systemic Factors

  • KMCO’s emergency response procedures and training did not properly limit the role of its operators during the emergency response.
  • KMCO’s plant culture relied on unit operators taking quick actions to stop a release before the site’s emergency response team assembled.
  • KMCO’s hazard evaluations consistently overlooked or misunderstood that its y-strainer was made from cast iron, a brittle material that existing industry standards and good practice guidance documents either prohibit or warn against using in hazardous applications, such as KMCO’s isobutylene system.
  • None of KMCO’s hazard evaluations identified the potential for liquid thermal expansion or other possible scenarios to develop high-pressure conditions within the piping system that included the y-strainer.
  • KMCO’s emergency response plan did not deal with training requirements.
  • KMCO’s PHA did not address the hazards of the y-strainer that failed or the hazards of an isobutylene release without installing remote emergency isolation valves.
  • KMCO did not effectively implement its emergency response plan.
  • KMCO did not train all employees in safe and orderly evacuation.
  • Material of construction information was not maintained for the y-strainer that failed or the isobutylene piping from the storage tank to the reactor system.
  • KMCO’s process safety information did not include the pressure relief valve design and design basis for certain safety relief valves that provide equipment overpressure protection.
  • KMCO did not have written procedures to manage changes for the reactor system piping and instrumentation diagrams or for the y-strainer that failed.

Failed Safeguards or Barrier Breakdowns

  • KMCO never activated its plant alarm system during the isobutylene release, explosion, or subsequent fires.
  • KMCO’s workers lacked the safety equipment they needed to stop (isolate) the isobutylene release from a safe location, such as from within the blast-resistant control room.
  • Unlike other portions of KMCO’s isobutylene piping, this piping section was not equipped with a pressure-relief device or otherwise protected from potential high-pressure conditions.
  • The charge pump’s inlet piping—including the y-strainer—lacked a pressure-relief device to protect it from liquid thermal expansion.
  • KMCO’s PHA did not address the hazards of the y-strainer that failed or the hazards of an isobutylene release without installing remote emergency isolation valves.
  • KMCO did not complete the implementation of the 2010 insurance recommendation to provide remote isolation capability in strategic process areas, including the isobutylene system.
  • KMCO’s 2018 PHA did not document an analysis of the potential high-pressure scenarios that could develop in the isobutylene piping from liquid thermal expansion hazards.
  • The R2 Building likely did not meet the NFPA’s requirements because it contained unclassified electrical equipment, such as motor starters, and the building was not pressurized to prevent flammable vapor from entering the building.

Recommendations

  1. Recommendation ID:
    Recipient: Altivia Oxide Chemicals, LLC
    Status: not issuing recommendations with this report
    Summary: The CSB urges Altivia to read this report closely and understand the factors that led to the incident at the KMCO facility and the lessons stemming from it. Moreover, if hereafter Altivia reinitiates the process or any equipment involved in this incident, the company should ensure that the facts, conditions, and circumstances that caused the incident—and contributed to its severity—are not repeated.

Key Engineering Lessons

  • Cast iron is widely recognized as a brittle material that should not be used in hazardous applications, including applications that involve flammable or toxic chemicals.
  • Piping systems should be equipped with protection from high-pressure conditions, where liquid thermal expansion or other scenarios can create a hazard.
  • Where remote isolation is not provided or is otherwise not available, clear policies and effective training are needed to help ensure that workers do not put themselves in danger to stop a chemical release.
  • Emergency response procedures and training should clearly communicate which incidents plant operators should respond to and which should be handled by a more qualified emergency response team.
  • Reliable facility alarm systems can help ensure effective emergency communication to alert people of danger and inform them of what actions are needed to protect life and health.

Source Notes

  • Primary source: CSB final report (source_priority 1), which overrides supporting documents where conflicts existed.
  • Supporting factual update used only for details not contradicted by the final report, including some early incident narrative and facility context.
  • Investigation closure plan and release schedule documents contained no incident-specific findings and were not used for causal conclusions.

Similar Incidents

Incidents sharing the same equipment, root causes, or hazard types.

Same Equipment

Same Root Cause

  • Cuisine Solutions Ammonia Release — Shared failure mode: Alarm Management Failure · Design Deficiency · Emergency Response Failure · Procedural Failure · Relief System Failure · Training Deficiency
  • Kuraray Pasadena Release and Fire — Shared failure mode: Alarm Management Failure · Design Deficiency · Management Of Change Failure · Procedural Failure · Relief System Failure · Training Deficiency
  • Morton International Inc. Runaway Chemical Reaction — Shared failure mode: Alarm Management Failure · Design Deficiency · Management Of Change Failure · Procedural Failure · Relief System Failure · Training Deficiency
  • Midland Resource Recovery Explosion — Shared failure mode: Design Deficiency · Management Of Change Failure · Procedural Failure · Relief System Failure · Training Deficiency
  • DuPont La Porte Facility Toxic Chemical Release — Shared failure mode: Alarm Management Failure · Design Deficiency · Emergency Response Failure · Management Of Change Failure · Procedural Failure

Same Hazard

← View in Knowledge Graph