Hazardous Materials Accident Report - Hazardous Materials Release From Railroad Tank Car With Subsequent Fire

Riverview, Michigan
July 14, 2001

NTSB Number: HZM-02/01
NTIS Number: PB2002-917002
Adopted June 26, 2002
PDF

Executive Summary

About 3:45 a.m., eastern daylight time, on July 14, 2001, at the ATOFINA Chemicals, Inc., (ATOFINA) plant in Riverview, Michigan, a pipe attached to a fitting on the unloading line of a railroad tank car fractured and separated, causing the release of methyl mercaptan, a poisonous and flammable gas. About 4:09 a.m., shortly after the Riverview Fire Department chief arrived on scene, the methyl mercaptan ignited, engulfing the tank car in flames and sending a fireball about 200 feet into the air. Fire damage to cargo transfer hoses on an adjacent tank car resulted in the release of chlorine, a poisonous gas that is also an oxidizer. The fire was extinguished about 9:30 a.m. Three plant employees were killed in the accident. There were several other injuries; most of the injured were treated for respiratory symptoms and released. About 2,000 residents were evacuated from their homes for about 10 hours. Two tank cars, railroad track, and plant equipment (including hoses and fittings) were damaged in the fire.

Probable Cause

The National Transportation Safety Board determines that the probable cause of the accident involving the release of methyl mercaptan from a tank car at the ATOFINA Chemicals, Inc., plant in Riverview, Michigan, was a fractured cargo transfer pipe that resulted from (1) the failure of ATOFINA to adequately inspect and maintain its cargo transfer equipment, and (2) inadequate Federal oversight of unloading operations involving hazardous materials. Contributing to the accident were ATOFINA's reliance on a tank car excess flow valve to close in the event of a leak from cargo transfer equipment and the company's failure to require appropriate safety equipment for employees involved in tank car loading and unloading operations.

As a result of its investigation of the accident, the National Transportation Safety Board identified the following safety issues:

  • The adequacy of ATOFINA's procedures for unloading tank cars containing hazardous materials.
  • The adequacy of Federal regulations and oversight for cargo transfer operations involving bulk containers transporting hazardous materials.

As a result of its investigation of this accident, the Safety Board makes safety recommendations to the U.S. Department of Transportation, the Federal Railroad Administration, the Environmental Protection Agency, and the Occupational Safety and Health Administration.

Recommendations

As a result of its investigation of the July 14, 2001, accident at Riverview, Michigan, the National Transportation Safety Board makes the following safety recommendations:

To the U.S. Department of Transportation:

Develop, with the assistance of the Environmental Protection Agency and the Occupational Safety and Health Administration, safety requirements that apply to the loading and unloading of railroad tank cars, highway cargo tanks, and other bulk containers that address the inspection and maintenance of cargo transfer equipment, emergency shutdown measures, and personal protection requirements. (I-02-1)

Implement, after the adoption of safety requirements developed in response to Safety Recommendation I-02-1, an oversight program to ensure compliance with these requirements. (I-02-2)

To the Federal Railroad Administration:

Issue a hazardous materials bulletin to warn companies involved in tank car loading and unloading operations that tank car excess flow valves cannot be relied upon to stop leaks that occur during those operations. (R-02-16)

To the Occupational Safety and Health Administration:

Assist the U.S. Department of Transportation in developing safety requirements that apply to the loading and unloading of railroad tank cars, highway cargo tanks, and other bulk containers that address personal protection requirements, emergency shutdown measures, and the inspection and maintenance of cargo transfer equipment. (I-02-3)

To the Environmental Protection Agency:

Assist the U.S. Department of Transportation in developing safety requirements that apply to the loading and unloading of railroad tank cars, highway cargo tanks, and other bulk containers that address personal protection requirements, emergency shutdown measures, and the inspection and maintenance of cargo transfer equipment. (I-02-4)

Notify all facilities that are required to submit risk management plans to the Environmental Protection Agency that tank car excess flow valves cannot be relied upon to stop leaks that occur during tank car loading and unloading operations and that those companies that have included reliance on such valves in their risk management plans should instead identify and implement other measures that will stop the uncontrolled release of product in the event of a transfer line failure during tank car loading or unloading. (R-02-17)