CSB Releases Case Study on Fatal 2008 Accident at Goodyear Tire and Rubber Plant in Houston; Cites Need for Emergency Drills, Following Pressure Vessel Codes
Washington DC, January 27, 2011 - A U.S. Chemical Safety Board (CSB) case study
released today on the 2008 heat exchanger rupture and ammonia release
at the Goodyear Tire and Rubber Company in Houston, Texas, identifies
gaps in facility emergency response training and calls for increased adherence to existing industry codes.
The
accident occurred on June 11, 2008, when an overpressure in a heat
exchanger led to a violent rupture of the exchanger, hurtling debris
that struck and killed a Goodyear employee walking through the area. The
heat exchanger contained pressurized anhydrous ammonia, a colorless,
toxic chemical, used as a coolant in the production of synthetic rubber;
five workers were exposed to ammonia released by the rupture.
On
the day prior to the accident, maintenance work required closing
several valves on the heat exchanger. CSB investigators found that
workers closed a valve that isolated the exchanger from a relief valve,
to replace a burst rupture disk located below the relief valve.
The
next day, at about 7:30 a.m. an operator closed another valve — this
one blocking a second, automatic pressure control valve – to begin
cleaning the process line with steam. Unaware that the isolation valve
was also closed – thus leaving no means of relieving excess pressure in
the exchanger, pressure continued to increase until the heat exchanger
exploded violently.
Managers
ordered the plant evacuated. However, CSB investigators found that on
the day of the accident the employee tracking system was not operating
properly, making it difficult to quickly account for all employees.
The
CSB found that a malfunction in the computerized electronic employee
badge tracking system delayed supervisors in immediately retrieving the
list of personnel in their area, requiring handwritten lists to be
generated. At about 1:20 p.m. an operations supervisor assessing the
damage to the incident area discovered a fatally injured employee buried
in rubble in a dimly lit area. The CSB case study notes that because
the fatally injured employee had been a member of the emergency response
team, her absence from the evacuation muster point was not considered
unusual.
CSB
Chairperson Rafael Moure-Eraso said, “The absence of this worker had
not been noted due to the lack of training and drills on worker
headcounts. Plant personnel were not provided with the proper training
to effectively manage this emergency. Company procedures called for
routine evacuation and shelter-in-place drills four times a year, but
such drills were not held for several years prior to the incident.
Management’s adherence to company procedures should have allowed for
effective communication between all members of the workforce and a more
robust emergency response structure.”
The
report further notes that maintenance work activity was not properly
communicated between maintenance and operations personnel, resulting in a
subsequent shift not being notified of the isolation of the pressure
relief line.
The CSB’s final report outlines several lessons learned including the
need to adhere to existing American Society of Mechanical Engineers
(ASME) Boiler and Pressure Vessel Code.
CSB
Investigations Supervisor Robert Hall said, “We found the accident
likely would not have happened had operators followed the ASME code.
It’s crucial that workers continuously monitor an isolated pressure
relief system throughout the course of a repair and reopen blocked
valves immediately after the work is completed.”
The
CSB’s report notes that the ASME code states that “Overpressure
protections shall be continually provided…whenever there is a
possibility that the vessel can be over-pressurized by a pressure
source.”
The
CSB is an independent federal agency charged with investigating serious
chemical accidents. The agency's board members are appointed by the
president and confirmed by the Senate. CSB investigations look into all
aspects of chemical accidents, including physical causes such as
equipment failure as well as inadequacies in regulations, industry
standards, and safety management systems.
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