I would not in passing the only reason I am willing to describe the preperation
of Na azide is that is it NOT an explosive. However, this does not make it safe!!
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Blasts and fires at air bag factories injure workers and slow production
By Tom Incantalupo STAFF WRITER
New York Newsday 16iii92
IN THIRTEEN YEARS of police work, Sgt. Gwen White-Erickson has seen plenty of
rubble. But the Michigan state police fire investigator wasn't ready for what greeted her
when she pulled up to TRW's plant in Romeo, Mich., last Dec. 17.
An hour and a half earlier, an explosion of automobile air bag propellant had leveled a
concrete block building that was about 40 feet long and wide.
"The walls sort of blew out; the roof just sort of collapsed in," she recalled. "It was just a
bunch of rubble. . .Ive never seen concrete blocks laid out that way."
It was an awesome display of the power of the chemicals used to inflate air bags and
an unpleasant side of the air bag success story.
Anyone who watches TV has seen videotape of air bags inflating in slow motion just in
time to cushion a test dummy before it slams into a steering column. By all accounts the
widespread installation of air bags in cars is saving lives and preventing injuries, and
the devices themselves have been remarkably reliable.
Federal safety regulators forecast that 2,400 lives will have been saved in the five years
ending at the close of 1995 and 29,000 serious injuries avoided, thanks to air bags -
nylon sacks that inflate with nitrogen gas in a fraction of a second to cushion
passengers in a crash.
But manufacturing those systems has proved on occasion to be a risky business, one
that involves working with highly unstable and explosive chemicals.
Since 1988, there have been at least 18 explosions or fires in factories that make air
bag components, mix the propellant that inflates air bags or handle waste products from
either. No one has been killed, but 23 workers have been injured, four seriously. Eleven
workers at the Romeo plant, about 30 miles north of Detroit, were slightly injured and
were treated for smoke inhalation and trauma.
But the accidents have not only affected workers; they are one reason why car makers
have been unable to install air bags in more models more quickly.
In one instance, a factory was shut down for almost a year and it created shortages of
air bag propellant that forced Ford Motor Co. to build 75,000 1991 Lincoln's without
passenger side air bags. They were later retrofitted.
Despite the manufacturing mishaps, experts say drivers don't have to worry about the'
propellant in their own air bag-equipped cars. Only a small amount of the chemical is in
the car, hermetically sealed.
State regulators say air bag manufacturing plants use some of the most stringent safety
practices of any industry. Much of the work is done by robots or by remote control. Still,
some of the mishaps have resulted from seemingly innocuous actions by workers.
The Michigan explosion, for instance, was the result of a spark created by a worker with
an allen wrench who was turning a screw to adjust a machine. The spark ignited some
propellant dust and a vacuum system carried the fire to another room where a barrel of
dust exploded, said White-Erickson.
An explosion in Mesa, Ariz., was set off when some water was dropped on burned air
bag propellant. Two months later, an enormous explosion at the same desert site
occurred because an aluminum scoop - similar to one a grocery shopper would use to
fill a bag I with bulk produce - was left in a mixing trough and the contact threw off
sparks. A worker in a Canadian factory set off an explosion when he tapped a hammer
on a pipe clogged with propellant.
At least one workplace safety activist says the 18 incidents are cause for concern.
"Clearly, there should be an investigation to see what can be done to reduce these
kinds, of explosions," says Joseph A. Kinney, executive director of a nonprofit research
group in Chicago. The National Safe Workplace Institute.
"Clearly, this industry, which is new, has not done its homework."
Similar concerns by a Michigan congressman led to a study in 1990 by the General
Accounting Office into the accidents up to that point. The GAO report was not critical,
but Rep. John Dingell (D-Mich.), who requested the study, expressed concerns in a
letter to the secretaries of labor and transportation and the administrator of the U.S.
Environmental Protection Agency about whether the states involved were adequately
monitoring the industry.
Still, there is no statistical evidence that the air bag industry's safety record is any worse
than any other handling highly-explosive substances - or any other industry, period.
In fact, state officials in Utah, Arizona, Michigan and Tennessee, where the industry is
concentrated, praise the companies operating within their borders for their safety
procedures and cooperation in investigating mishaps.
Further, the number of accidents has to be viewed in the context of the industry's
production volume. The Insurance Institute for Highway Safety, a trade group, says
almost 6 million air bag-equipped cars have been sold in this country since the 1980s
and it says most air bag systems were produced in North America including those in
many imported cars.
Noel Baker, senior vice president for marketing at a new company getting into the
manufacture of propellant and the cannisters that hold it, says the accidents were an
unfortunate but not surprising byproduct of the industry efforts to handle greater
amounts of material to satisfy burgeoning demand"
"What you've seen, I think, are some of the strains produced by this
tremendous ramp-up," Baker said. His company, Breed Automotive,
which is based in New Jersey but has set up its plant in Florida, will mix
propellant with a new process that involves producing small batches simultaneously
rather than one large batch and by shaking, not stirring, ingredients.
Concerns about the safety of air bags goes beyond the mixing of propellant and its
placement in inflator modules. The United Auto Workers Union is worried about
inadvertent deployments -of air bags - perhaps from electrical short circuits or static
electricity - as its. people install the systems in cars on assembly lines. Though that
hasn't happened yet, one concern is that a deployment a loud and violent
occurrence could push a worker into running machinery.
"It has the potential to be a real big problem," said Dick Monczka, who represents the
union at a workers health and safety center it runs jointly with General Motors near
Pontiac Mich. The center has written a 70-page safety manual and produced A
videotape to train workers handling the equipment.
There is concern as well about safe disposal of unused propellant when, cars are
scrapped. Some auto recyclers are worried about explosions or poisoning of workers
with the chemical involved.
Eventually, all cars and light trucks will have air bags on both the driver, and passenger
side by the 1998 model year for cars, the 1999 model year for light trucks.
The industry that produces air bags, in North America is dominated by TRW Safety
Systems Inc., based in Washington, Mich., with plants in Mesa, Romeo, Cookeville,
Tenn., and McMasterville,, Quebec; Morton International, with,, plants in Ogden,
Brigham City and Promontory, Utah and, in a joint venture with Allied Signal's Bendix
unit, in Maryville, Tenn.
So far, most of the accidents reported have involved operations that mix chemicals that
make propellant the material that is ignited to form the nitrogen gas that inflates the
bag. One occurred in a factory installing propellant in inflators, two occurred in facilities
manufacturing the basic ingredient of propellant, sodium azide, and one explosion
occurred at a facility handling waste propellant.
Sodium azide is flammable but not explosive. However, it can form explosives when it
comes into contact with water, acidic solutions or with heavy metals such as copper or
lead. The finished propellant, as installed in cars also is highly flammable, but not
explosive.
The fact that no one has been killed in 18 incidents is attributable to intensive safety
measures, industry officials say.
Buildings are constructed with three specially reinforced walls and one that is
designed to give way easily if there is an explosion, to channel the force of blasts away
from the people working inside.
Much of. the work in high-danger areas, such as where propellant is
mixed or pressed into pellets or wafers done by robot or remote control, with operators
monitoring work via TV cameras. Cement block walls separate workers performing
different manufacturing steps. Buildings have state-of-the-art fire suppression systems.
In all of the things you do, in the factories you build and the procedures you use, you
function as though there could be an incident with pyrotechnics says George Virchoff,
vice president for automotive programs at Morton. "You always function so that, you:
had an incident, you would have injury to personnel."
Cleanliness, he said, is practiced religiously. Propellant, once mixed, is moved in small
quantities to the plan where it will be loaded into inflators.
The machines that do the loading Kirchoff said, operate automatically and are vented
through a stack that juts up through the buildings roof,
that any fire or explosion would b channeled up and out of the structure. He said the
two explosions at Morton' facilities did minimal damage and, while their precise causes
was proprietary information, the company ha learned from the experience.
"We have mixed more than 1.5 million pounds of gas generants [propellants] since
those accidents without incident," Kirchoff said.
The mishaps have occurred as pressure has built on the industry to increase
production; Americans have largely been sold on the lifesaving benefits of air bags but
the supply of them is limited. While it is difficult to draw a connection between limited air
bag supplies and the accidents, the industry has not been found entirely blameless
when officials have investigated the accidents.
Chemical Waste Management, an Illinois hazardous waste disposal company to whom
TRW had been trucking waste propellant from Arizona, agreed last month to pay the
Illinois Environmental Protection Agency a $1.9 million fine - without admitting wrong-
doing - for violations of state environmental law after explosions in January, and
February, 1991, at Chemical Waste's hazardous waste incinerating plant in Sauget, Ill.
Only the January explosion involved air bag propellant. But the incidents caused
problems for TRW: It had no place else to send waste propellant. Called in by TRW in
February of last year, Arizona state officials found thousands of pounds of it at one of
TRW's Mesa plants. Some of the propellant had exceeded a 90-day state storage limit.
Under a settlement signed last September, TRW paid a $35,000 penalty.
TRW has paid other fines in Arizona in connection with its air bag operations. Before
the first accident, Arizonas Division of Occupational Safety and Health fined TRW $400
for failing to properly train and inform workers about hazardous chemicals. Another
state fine, for $640, was for an explosion July 28, 1989, at its plant on the north side of
Mesa.
"We're not perfect no one is," said Tom Cresante, director of operations at the TRW
plant. "We're dealing with pyrotechnics, and we're trying to do something that maybe
other industries haven't done bringing it to a high volume
The Boom in Air Bags
The probable causes of reported fires and explosions at air bag manufacturing sites or
the sites their wastes are handled.
Dec. 17, 1991: TRW, Romeo, Mich. Eleven workers injured, building destroyed, when
air bag propellant explodes. A spark from wrench set off explosion.
Jan. 25,1991: Chemical Waste Management, Sauget, Ill. Cannister of waste propellant
falls into dumpster of hot ash, explodes. No injuries.
January, 1991: TRW, Mesa, Ariz. No injuries, no damage from what fire official describe
as minor fire.
April 1991: TRW, Mesa. Small fire; no injuries.
March 14,19-": Sabag lnc., Quebec, Canada. Three workers seriously hurt in explosion
atop conveyor pipe full of propellant, Caused by spark from mallet blow to unclog pipe.
Dec. 8,1989: Sabag Inc. Propellant ignited when employees drill above equipment used
to grind sodium azide. Drill cuttings ignite propellant mix. No injuries.
Nov. 1, 1989 ICI Explosives, Canada Inc., Quebec. Fire begins from chemical reaction
between wet sodium azide stored in drums and raw sodium that had been in same
drums. Drums had not been cleaned as required. No injuries.
Oct. 8, 1989. ICI Explosives, Quebec. Pressure-reducing valve regulating steam heat
going to sodium azide dryer was too close to dryer, causing sodium azide to overheat
and ignite. No injuries.
Aug. 14,1989 Morton International, Utah. Propellant mixture ignited by unknown source.
No injuries.
July 28, 1989 TRW, Mesa. Five workers Injured, building heavily damaged when friction
from aluminum scoop left in mixing bay produces sparks, ignites propellant.
July 24, 1989: Morton international. Propellant ignites when broken piece of press falls
into press die. No injuries.
July 13,1989: Sabag Inc. Moisture from dry ice contacts sodium azide, forms explosive
chemical, fire occurs. No injuries.
June 16,17,18, 1989: Talley Defense Systems, Mesa. Series of three explosions set off
by friction igniting propellant dust in ball bearing assembly of a mixer. No injuries.
May 1989. Talley Defense Systems. Two workers hurt in explosion In open bum pit
when water poured into pit reacts with sodium residue of burn propellant.
March 11, 1989: Sabag Inc. Spark from static electricity ignites propellant. No injures.
Feb 17, 1968: Sabag Inc. One worker injured seriously, three others hurt, when spark
from screwdriver ignites propellant
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donald j haarmann independently dubious