CUI Major Incident# 6: First Chemical Corporation Explosion and Fire

Date and Place of the Incident:

On October 13, 2002, an explosion occurred at the Bayou Cassotte Industrial Park in Pascagoula, Mississippi.

Summary of the Incident:

1. Steam leaking through manual valves heated mononitrotoluene (MNT) inside a distillation column caused an explosion at First Chemical Corporation (FCC) facility.
2. An MNT storage tank ruptured and caught fire that lasted for about three hours due to flying debris.
3. Fragments from the explosion reached through the adjacent facility and small fires initiated along the highway.
4. A local community shelter in place was conducted to minimize potential exposure to the hazardous chemical.

Root Cause of the Incident:

1. Corrosion under insulation was the root cause of the incident.
2. Leaking occurred at the manual valves in the steam line due to the accumulation of steam vapor and moisture.
3. The decomposition of MNT through the leaking steam resulted into a runaway chemical reaction and explosion.

Financial Loss to Freedom Industries:

First Chemical Corporation agreed to pay $751,000 for civil penalties because of the damages incurred during the explosion.

Environmental Impact of the Incident:

1,200 gallons of hazardous chemical were released to the environment, but no exposures were reported. Fire from ruptured tanks and burning debris was immediately controlled. The extent of the damage reached off-site vicinity as light and heavy fragments were found on Chevron area property.

Fatality or injury due to the Incident:

Three employees were brought to a hospital for treatment due to minor cuts and abrasion.

 Non-Compliance of Safety Guidelines and Reliability Practices:

1. FCC Pascagoula facility lacked hazard analysis system for the continuous MNT distillation columns.
2. No system in place to ensure sufficient layers of protection such as high temperature interlock to stop the heat input at the continuous MNT column.
3. Inadequate operating procedure wherein no caution was provided about the nature of MNT and the potential instabilities of the material.
4. Ineffective work practice and lack of comprehensive training wherein hazards were not properly assessed and communicated.
5. Inadequate programs to ensure integrity of isolation valves in the steam line connected to the MNT column.

Recommendations to Avoid Corrosion:

1. Set up of appropriate protection layers such as alarms and interlocks to avoid unforeseen chemical reaction releases.
2. Perform adequate maintenance and establish inspection schedules to ensure structural integrity and detect possible signs of corrosion such as wall and pipe thinning.
3. Proper location of pressure relief devices to prevent generation of vapors and accumulation of moisture that could cause external corrosion.

Links to the photos/videos:

The websites below provide full access to the incident report, useful insights, and related images.

https://www.csb.gov/assets/1/20/first_report.pdf?13794

https://www.wlox.com/story/970616/explosion-at-first-chemical-contained/