Kinston, NC, September 23, 2004 — The U.S. Chemical Safety
and Hazard Investigation Board (CSB) today released its final report on
the investigation of last year’s fatal dust explosion and fire at West
Pharmaceutical Services Inc., finding inadequate engineering at the destroyed
plant and calling on North Carolina to adopt National Fire Code controls
on combustible dust for industrial facilities statewide.
Application of the national code, known as National Fire Protection
Association (NFPA) 654, would require that businesses in all North Carolina
jurisdictions adhere to recognized good practices for preventing combustible
dust explosions. Those measures include segregating dust-producing operations;
sealing walls, ceilings, and partitions to prevent intrusion and accumulation
of dust; using only electrical equipment suitable for potentially explosive
atmospheres; and regularly training employees on combustible dust hazards.
The CSB report determined four root causes of the accident at West:
the company’s inadequate engineering assessment for combustible powders,
inadequate consultation with fire safety standards, lack of appropriate
review of material safety data sheets (MSDSs), and inadequate communication
of dust hazards to workers. The investigation report and recommendations
will be considered for approval by CSB board members at a public meeting
this evening in Kinston.
“If the good safety practices described in the National Fire Code and
elsewhere had been followed at West, this tragic accident would likely
have been avoided,” said CSB lead investigator. He also stated that “we will
therefore be recommending that the State of North Carolina make compliance
with the dust code mandatory.”
The accident on January 29, 2003, killed six workers and injured 38
others, including two firefighters. The blast could be felt 25 miles
away, and burning debris ignited fires in wooded areas as far as two
miles away. A large fire at the plant burned for two days.
In addition to recommending that North Carolina’s Building Code Council
adopt NFPA 654, the report calls on the state Department of Labor to
identify the industries at risk for combustible dust explosions and
conduct an educational outreach program to help prevent future accidents.
The report urges increased training of North Carolina fire and building
code officials on combustible dust hazards. It also recommends that
West improve its material safety review procedures, revise its project
engineering practices, communicate with its workers about combustible
dust hazards, and follow safety practices contained in NFPA 654 at all
company facilities that use combustible powders.
Consistent with preliminary findings released in June 2003, CSB investigators
concluded that the blast at West was caused by the ignition of a significant
amount of polyethylene dust, which had accumulated above a suspended
ceiling over a production area where slabs of rubber were made. The
company uses the rubber to make medical items such as syringe plungers
and rubber stoppers for vials. In the process, rubber strips were passed
through a tank of fine polyethylene powder and water and were then air-dried
with fans. Polyethylene dust with the consistency of talcum powder became
airborne in the process, and the dust was drawn above the suspended
ceiling by heating and air conditioning intake ducts, investigators
said.
The CSB report said that while dust removal and good housekeeping were
priorities at the facility, dust nevertheless accumulated above the
suspended ceiling over time and went unrecognized as a serious hazard.
Maintenance workers reported accumulations of one-quarter to one-half
inch of dust above the tiles and other surfaces; the National Fire Code
limits combustible dust accumulations to 1/32 of an inch.
The CSB Chairman said, “this tragic accident could have
been avoided if the design and operation of the facility had taken into
account the hazards of combustible dust. Unfortunately, West lacked
an effective understanding of the danger, and regulations did not require
adherence to control measures. Our findings underscore the need for
stronger fire codes on the books and for combustible powder manufacturers
to adequately identify the hazard of their products and warn customers
to prevent such disasters.”
CSB’s investigation determined that West company files included documents
warning of the explosive properties of polyethylene powder. However,
the company lacked effective management procedures for incorporating
those warnings into the engineering and operation of the rubber-making
process. In assessing the hazards of the powder, West relied on a material
safety data sheet (MSDS) prepared by a vendor that produced a polyethylene-water
slurry, not the original MSDSs from the powder manufacturer, which did
contain dust warnings. The MSDS from the slurry producer, Crystal Inc.
– PMC, did not consider the hazards once the slurry dried – a contributing
cause in the accident. Among other safety recommendations, investigators
urged that Crystal’s MSDS be modified.
The report noted that during a previous welding operation at the Kinston
plant, accumulated polyethylene powder had briefly ignited near the
rubber production equipment, without causing an explosion. Although
the incident indicated the combustibility of the powder, West did not
conduct a documented internal investigation of this incident, which
could have led to a better understanding of the dust hazard.
The CSB lead investigator said that extensive damage at the plant made it impossible
to determine what event initiated the dust explosion but noted the report
identifies four theories: a batch of rubber that overheated and ignited;
an electrical ballast or light fixture that ignited accumulated dust;
a spark caused by a possible electrical fault; or ignition of dust in
a cooling air duct feeding an electric motor.
The CSB lead investigator also said “the ultimate source of the large explosion that destroyed
the plant was the dust accumulation, and that is where future efforts
need to focus. Without accumulated fuel, dust explosions simply do not
occur.”
The explosion in Kinston was one of three fatal dust explosions in
2003 under investigation by the CSB. A phenolic resin dust explosion
at an automotive insulation maker in Corbin, Kentucky, in February caused
seven fatalities and injured 42, and an aluminum dust explosion at an
Indiana automotive parts maker in October killed one worker and burned
two others. These and other recent dust explosions are a focus of CSB’s
investigation on combustible dust hazards, which is currently underway.
That study will review possible national initiatives to reduce the occurrence
of industrial dust explosions.
The CSB is an independent federal agency charged with investigating
industrial 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 safety management systems. |