January, 2023

This is a repeating event

202323JanAll DayDupont (Belle) Toxic Release 2010DuPont Belle (US-WV)Lessons:Asset integrity,Audits & Reviews,Competency,Compliance with Standards,Emergency Preparedness,Incident Investigation,Operating Procedures,Risk AssessmentIndustry:ChemicalsCountry:United StatesLanguage:ENLoC:Deterioration Origin: CSB Incident:Gas/vapour/mist/etc release to airHazards:Corrosive,Flammable,ToxicContributory Factors:Containment FailureImpact:HUMAN (On Site Fatalities)Effects:1-10 FatalitiesMaterial:Methyl Chloride,Oleum,Phosgene


On January 22 and 23, 2010, three separate incidents at the DuPont plant in Belle, WV, involving releases of methyl chloride, oleum, and phosgene, triggered notification of outside emergency response agencies. The incident involving the release of phosgene gas led to the fatal exposure of a worker performing routine duties in an area where phosgene cylinders were stored and used.

Operators discovered the first incident, the release of methyl chloride, the morning of January 22, 2010, when an alarm sounded on the plant’s distributed control system monitor. They confirmed that a release had occurred and that methyl chloride was venting to the atmosphere. Managers assessing the release estimated that more than 2,000 pounds of methyl chloride may have been released over the preceding 5 days.

The oleum release, the second incident, occurred the morning of January 23, 2010. Workers discovered a leak in an overhead oleum sample pipe that was allowing a fuming cloud of oleum to escape to the atmosphere. The plant fire brigade, after donning the appropriate personal protective equipment, closed a valve that stopped the leak about an hour after it was discovered. No injuries occurred, but the plant called the Belle Volunteer Fire Department to assist.

The third incident, a phosgene release, occurred later that same day when a hose used to transfer phosgene from a 1-ton cylinder to a process catastrophically failed and sprayed a worker in the face while he was checking the weight of the cylinder. The employee, who was alone when exposed, was assisted by co-workers who immediately responded to his call for help. Initial assessments by the plant’s occupational health nurse indicated that the worker showed no symptoms of exposure prior to transport to the hospital for observation and treatment. A delayed onset of symptoms, consistent with information in phosgene exposure literature, occurred after he arrived at the hospital. His condition deteriorated over the next day and he died from his exposure the next night.



Methyl Chloride Incident (January 22, 2010)
1. DuPont management, following their Management of Change process, approved a design for the rupture disc alarm system that lacked sufficient reliability to advise operators of a flammable methyl chloride release.

Oleum Release Incident (January 23, 2010)
1. Corrosion under the insulation caused a small leak in the oleum pipe.

Phosgene Incident (January 23, 2010)
1. DuPont’s phosgene hazard awareness program was deficient in ensuring that operating personnel were aware of the hazards associated with trapped liquid phosgene in transfer hoses.
2. DuPont relied on a maintenance software program that was subject to changes without authorization or review, did not automatically initiate a change-out of phosgene hoses at the prescribed interval, and did not provide a back-up process to ensure timely change-out of hoses.
3. DuPont Belle’s near-miss reporting process was not rigorous enough to ensure that the near failure of a similar phosgene transfer hose, just hours prior to the exposure incident, would be immediately brought to the attention of plant supervisors and managers.
4. DuPont lacked a dedicated radio/telephone system and emergency notification process to convey the nature of an emergency at the Belle plant, thereby restricting the ability of personnel to provide timely and quality information to emergency responders.

Image credit: CSB


CSBUS Chemical Safety Board