[Music] Sherburne: Everything was changed that morning. And when Kelly and I
got to the hospital, the first thing the doctors told us,
walking in the door, was he burned 95 percent of his body
and we don't think he's going to make it. There's nothing you can say to that. [Music] Narrator: January 31, 2011. Two maintenance workers were
troubleshooting a problem with a bucket elevator at the Hoeganaes Powdered
Metals Plant in Gallatin, Tennessee. Suddenly, fine particles of iron
dust ignited ... [Sound of explosion] when workers attempted to restart the elevator's motor. The CSB investigation into
that accident was underway, when just two months later, on March 29, a similar flash fire
burned another Hoeganaes worker. At a news conference in Tennessee on May 11,
the CSB released laboratory test results, demonstrating the combustibility of
even small amounts of the iron dust, when dispersed in air in the
presence of an ignition source. Just 16 days after the CSB released those test results,
on May 27, a hydrogen explosion erupted in the plant. [Sound of explosion] The blast shook loose iron dust accumulation
from the upper reaches of the building, which ignited and
rained down on workers. Moure-Eraso: Combustible dust is a
serious workplace hazard across the country. Since the Chemical Safety Board
was established in 1998, three of the deadliest accidents we have investigated
have been combustible dust explosions. They are entirely preventable, just like
the dust fires that occurred at Hoeganaes. Narrator: The Hoeganaes Corporation
is a subsidiary of GKN, a multinational engineering company
headquartered in the United Kingdom. The Hoeganaes Gallatin facility,
located some 30 miles from Nashville, employs about 180 workers in the production of
powdered metals, with a capacity of 300,000 tons per year. The main product is over 99 percent pure iron powder,
used primarily in the automotive industry. The manufacturing process releases
combustible metal dust into the workplace. Banks: The dust must be controlled
and not allowed to accumulate. But when the CSB examined the Hoeganaes facility
after each of the three accidents, we were alarmed to discover literally tons of
accumulated dust on surfaces throughout the facility. Narrator: At the Hoeganaes facility,
iron powder travels through the plant by a system of conveyors
and bucket elevators. The belts on the bucket elevators
had a tendency to become misaligned, causing the motors to
overload and shut down. On January 31, 2011, a
maintenance mechanic and an electrician were sent to inspect a bucket elevator
that had just malfunctioned, to see if the belt was off-track. It appeared to be aligned properly and the mechanics
radioed the control room operator to restart the motor. The dust collection bag house had been out of
service periodically over the previous week. Fine particles of iron dust
remained in the area of the motor. As the motor restarted, combustible iron dust
was suddenly dispersed into the air. The two workers were immersed
in a thick dust cloud. Almost immediately the iron dust found an
ignition source ... [Sound of explosion] likely an electrical arc
from exposed wiring on the motor. A flash fire erupted,
engulfing both workers. Both men were severely burned. The first worker died from his injuries
just two days after the accident. The second survived for nearly four months,
but died in May of 2011. After the first accident, the CSB documented
that combustible iron dust was visible in the air and that it coated most surfaces
up to four inches deep. These CSB investigation photos show the
accumulated dust on elevated surfaces, where the dust could be
readily dislodged and ignited. The CSB report noted
that engineering controls, such as enclosing conveyors and installing
properly designed dust collection equipment are the best ways to
prevent dust accumulations. But as this CSB investigation video shows, the plant's
powder-handling equipment was not adequately sealed. Combustible dust was always
present in the air inside the plant. In this investigation video,
dust particles ignite and sparkle as they contact an indoor hydrogen gas flare
from one of the plant's furnaces. And employees told CSB investigators that
dust collectors were often down for maintenance. Housekeeping measures
were the last line of defense for removing the large amounts of dust
that constantly accumulated on plant surfaces. But the CSB found that housekeeping
at Hoeganaes was ineffective. Those conditions led to a
second serious accident at the plant, less than two months after
the first deadly flash fire. On March 29, 2011, a
Hoeganaes engineer attempted to reconnect a gas line to a 20-foot high furnace,
following maintenance. But he was having difficulty,
standing on a ladder held by a second worker. He tried hammering
the line into place. As the hammer struck,
[sound of hammering] iron dust that had accumulated on the
side of the furnace was lofted into the air. The iron dust ignited ... [Sound of explosion] burning the engineer,
who jumped and fell from the ladder. Partly protected by a
heavy flame-resistant coat, he received first and second-degree burns
to both of his thighs. Banks: The buildup of so much iron dust
near a furnace, with open flames and hot surfaces,
was a recipe for disaster. A fire was basically inevitable the
moment the dust was lofted into the air. Narrator: Even small amounts of iron dust
can produce intense flash fires when ignited, as demonstrated in the
CSB's laboratory testing. Banks: If just an ounce of dust
can produce such a serious fire, you can imagine the magnitude
of the fire and explosion hazard from the estimated tons of dust
accumulated at the Hoeganaes plant. Narrator: Still, Hoeganaes
and its corporate parent, GKN, did not take effective measures
to control the dust hazard. Around 6:00 a.m. on the morning of May 27, 2011, operators near one of the plant's furnaces
heard a hissing noise [hissing noise] that they identified
as a possible gas leak. They believed that that the leak came
from piping somewhere below the furnaces, inside a trench
under large steel covers. Six mechanics were sent to find and
repair the leak, as another operator stood by. They assumed it was similar to another recent leak
that involved nitrogen, an odorless, nonflammable gas. Unknown to the workers, the leak actually
involved a different odorless, invisible gas; highly flammable hydrogen, used in
the plant's massive annealing furnaces. Using a forklift, maintenance personnel removed a
trench cover above the area of the suspected leak. As the cover was wrenched upward, metal sparks
ignited the hydrogen, causing a powerful explosion. [Sound of explosion] Narrator: Hydrogen continued to
leak from piping, fueling a jet fire. The force of the explosion
lofted large quantities of iron dust, that had accumulated on rafters
and overhead surfaces. Falling clouds of dust ignited as
they contacted the flames below. [Sound of explosion] Narrator: Visibility was reduced by
the large quantity of dust in the air. One eyewitness reported
that even with a flashlight, he could only see three to four feet ahead
as he tried to escape. Five workers, including the operator standing by
the trench and four of the mechanics were injured; three of them with severe burns. Two of those workers would die
from their injuries within days. The third injured worker
succumbed six weeks later. The CSB noted that on
the day of the accident, maintenance crews were allowed to work without
testing for dangerous concentrations of flammable gas and that the facility had no procedures
to properly mitigate flammable gas leaks. Hoeganaes did not have an
effective mechanical integrity program, allowing corrosion in piping to go unnoticed
until the piping failed. And despite mounting evidence
of a serious hazard, Hoeganaes did not make major improvements
in its dust control program. Hoeganaes tested its powdered metals
for combustibility in 2009 and 2010, following warnings from an insurance audit about
the potential for a dust explosion at the plant. The company collected and tested three powder samples
in 2009, all of which had combustible properties, similar to the dust later
collected and tested by the CSB. Hoeganaes was also aware of
the combustibility of iron dust, because earlier flash fires had occurred
when maintenance workers used welding torches on
dust-covered conveyor belts. Banks: When the Hoeganaes facility
was built more than 30 years ago, it was not designed according to good
practice guidelines on combustible dust, such as those set forth by the
National Fire Protection Association or NFPA. And during its decades of operation, it was
never redesigned to address the serious dust hazard. Narrator: The Hoeganaes facility has numerous
flat overhead surfaces where dust can accumulate and they are difficult to reach and clean. NFPA 484, the Standard for Combustible Metals,
recommends that floors, elevated platforms and gratings be designed to prevent dust accumulations
and to facilitate cleaning. The NFPA Standard also requires that
all machines that release combustible dust be connected to a
dust collection system. The City of Gallatin requires
industrial facilities, including Hoeganaes, to comply with the
International Fire Code. The Code includes a brief chapter
on combustible dust. The chapter references the far more
detailed dust safety standards of the NFPA, but does not specifically
require companies to follow them. As a result, the CSB recommended that the
International Code Council revise the International Fire Code to mandate compliance with the combustible
dust safety requirements set forth by the NFPA. In its 2006 study on the
hazards of combustible dust, the CSB recommended that the
Occupational Safety and Health Administration create a combustible dust standard
for general industry. In response, OSHA initiated a
National Emphasis Program in 2007 to target industries with combustible dust hazards
for additional inspections and enforcement. Two years later, OSHA announced it would begin rulemaking
on a comprehensive standard for general industry. Solis: And I'm announcing today that OSHA
will be begin the rulemaking on combustible dust. Narrator: But in 2011, at the
time of the accidents at Hoeganaes, a specific standard had not
yet been proposed or completed. Narrator: As a result, in its final report
on the accidents at Hoeganaes, the CSB recommended that OSHA develop and publish a
proposed combustible dust standard within one year and ensure that the new standard includes
coverage for combustible iron and steel powders. Meantime, until the dust
standard is completed, the CSB recommended that facilities like
Hoeganaes, that handle iron and steel powder, should be included in OSHA's National
Emphasis Program for combustible dust. Banks: It is a tragedy that five lives were lost
at the Hoeganaes facility from these accidents. The CSB believes that adhering
to recommended industry practices will greatly reduce the potential
of a future dust fire or explosion. Moure-Eraso: Dust fires and explosions continue to
claim lives and destroy property in many industries. More must be done to control this hazard. No more lives should be lost
from these preventable accidents. Thank you for watching
this CSB Safety Video. Narrator: For more information on the CSB's
Hoeganaes investigation, please visit CSB.gov.
