EH-9304 April 1993 Occupational Safety Observer
APRIL 1993
Occupational Safety OBSERVER
Lithium Fire
Knowledge of Material Characteristics Pays
Workers handling chemically reactive materials must possess
a thorough understanding of the characteristics and potential
dangers of those substances. This knowledge is important not
only for preventing accidents, but also for mitigating their
effects. The following incident is a reminder of the importance
of proper procedures and knowledge of material characteristics.
What happened
On December 12, 1992, two contractor employees at the
Lawrence Berkeley Laboratory received a routine request to remove
lithium ribbon from a laboratory research area. The workers, who
were contractor-certified waste handlers, complied and
transported the ribbon to the Hazardous Waste Handling Facility
(HWHF) for stabilization pending its final disposition. As
received, the lithium was doubly packaged in airtight plastic
storage bags and placed inside a transport container. At the
HWHF the workers proceeded to follow the contractor's published
procedure for stabilizing alkali metals (lithium is an alkali
metal).
The procedure required that the lithium first be placed in a
container under a fume hood and then completely immersed in
solvent. The workers interpreted "solvent" to mean methanol,
which is commonly available at the HWHF, and proceeded
accordingly. Almost immediately, the worker pouring the methanol
into the container observed the mixture rapidly heat up and
ignite as the lithium reacted with the water in the methanol. He
yelled to his co-worker, removed the container with the reacting
materials from the fume hood, and placed it in a second
polyethylene container on the floor. The co-worker grabbed a
readily available dry chemical extinguisher rated for Class A, B
and C fires, and shouted to a laboratory employee to notify the
fire department and to have the building evacuated.
The co-worker then unsuccessfully attempted to put out the
Class D fire with the incorrect fire extinguisher. When this
effort failed, the workers, now completely engulfed in smoke,
moved both the containers and their contents outside into the
open storage yard. Once outside they poured absorbent sand, a
commercial waste packing fire suppressant, onto the reacting
material and effectively extinguished the fire.
Although the lithium fire was out, sparks from that fire had
ignited documents and cardboard packing materials inside the
building. The secondary fire activated the building's automatic
sprinkler system.
The laboratory fire department responded to the site within
five minutes of notification and emergency response procedures
were executed professionally. Per the existing mutual aid
agreement, the Berkeley fire department HAZMAT team was summoned
to provide back-up support. Because the initial response was to
a lithium fire, fire fighters immediately secured the building's
sprinkler system and assessed the situation. Once it became
apparent that there were actually two separate fires, fire
Page 2 Occupational Safety OBSERVER
fighters entered the building and ensured that the second fire
was completely extinguished. The fires caused minimal damage to
the facility and the workers were treated for eye and throat
irritation.
Investigation
The investigation into the incident identified the primary
cause as an improper or imprecise written procedure. Lithium
reacts with water to form hydrogen gas and the reaction can
generate sufficient heat to ignite the hydrogen. To prevent this
reaction, alkali metals such as lithium are routinely stored
immersed in water-free solvent or mineral oil. The procedure
merely specified, in generic terms, a neutral solvent or mineral
oil. The solvent chosen by the workers, methanol, was incorrect
and reacted with the lithium.
The investigation cited training deficiencies and inadequate
management supervision as contributing causes. The following
points were identified:
o The waste generator who passed the lithium to the workers
lacked the training and knowledge to package the lithium
correctly. Had he placed the lithium properly in mineral
oil, the workers responsible for waste storage would not
have attempted to immerse it themselves.
o The workers should not have removed the lithium from the
generation site or attempted to prepare it for storage
without first notifying the responsible individual that it
had been incorrectly packaged.
o The workers used the wrong class of fire extinguisher in
their initial response to the fire, even though a Class D
fire extinguisher was located inside the HWHF. (The
facility was in compliance with OSHA regulation 29 CFR
1910.157, which requires proper [Class D] fire extinguishers
or other containers of Class D extinguishing agent to be
located within 75 feet of a combustible metal working area.)
It is possible that this extinguisher may have been
overlooked by the workers in the frenzy of the moment.
Fire Classes
A Ordinary combustibles such as paper, wood, or
cloth
B Flammable combustibles such as liquids or greases
C Energized electrical equipment
D Combustible metals, such as magnesium or
sodium
Lessons learned
What can be learned from this incident? Valid, unambiguous
written procedures should be available. Ideally, these
procedures should include cautionary notes on possible reactions
that may occur during stabilizing operations and should specify
immediate actions.
Occupational Safety OBSERVER Page 3
Additionally, the availability of adequate written
procedures is not in itself sufficient. All workers dealing with
potentially dangerous material must receive periodic refresher
training on the potential dangers of the material and on the
correct and immediate response actions. This training should be
tested through periodic drills and other means to maintain
awareness and provide feedback to supervisors on worker
proficiency. Workers should also know to provide feedback to
others when they observe an unsafe situation, such as improperly
packaged hazardous materials. The impact of an active
supervisory staff cannot be over emphasized in the identification
and prevention of potential problems.
Finally, management oversight of subcontractors is important
in accident prevention. Management at all levels must maintain a
continuing awareness of their subcontracted companies'
capabilities. How well do you verify your subcontractors'
abilities to perform their missions?
Industrial Incident
Three Deaths Attributed to Lockout/Tagout Failure
Lockout/tagout incidents seem to appear frequently in the
pages of the Observer. While each is unique in its circumstances
and consequences, a common theme runs through many of them:
workers who grow accustomed to working with their equipment
sometimes overlook the necessity to lock it out before working on
it, and accidents occur. This month, we highlight a case in a
California sawmill, in which three workers failed to adhere to
lockout/tagout procedures and were killed by the piece of
machinery on which they were working.
What happened
The three equipment operators, one of whom was a "lead man"
supervising his fellow workers, died September 8, 1992, in a
California sawmill accident. The three entered a jammed
"debarking" machine to adjust its operation and clear a log jam
without performing the lockout procedure that would have
prevented the machine from starting while they were inside. The
precise details of the accident may never be determined, but it
appears that once the log jam was cleared the hydraulic mechanism
resumed operations with the workers still inside.
During the investigation of the incident, other employees
testified that although lockout/tagout procedures existed, they
had not always been followed in the past. The California
Division of Occupational Safety and Health inspector called this
"a totally, absolutely preventable accident." Cal/OSHA cited the
lumber company for three violations of state worker safety
standards.
In addition to the relevant state safety codes, Federal OSHA
regulations apply in this case. In the Appendix to 29 CFR
1910.147, OSHA describes the elements of a minimal energy control
program, including the need to verify that energy sources have
been disconnected before working on equipment. Recognizing that
familiarity and experience are not substitutes for prudent safety
Page 4 Occupational Safety OBSERVER
practice, Section 1910.147(c) requires that such a written
program apply to all employees.
Lessons learned for DOE
Workers at DOE sites are unlikely to encounter log jams in
debarking machines, but there are several lessons from this
incident that are highly relevant for DOE sites. These lessons
focus on the importance of using appropriate lockout/tagout
procedures every time.
o Lockout/tagout procedures must be used consistently to be
effective. Inconsistent use of safety procedures can lead
to bad habits and complacency. Doing it right every time is
the only way to ensure safety.
o All workers should take the time to double-check that the
equipment has been properly locked and tagged out before
working on it. It's never safe to assume that one of your
co-workers will have taken care of it.
o Managers need to communicate not only the rules about
lockout/tagout procedures, but also the risks of failing to
follow these procedures and the reasons that the procedures
exist.
o Workers must remember that experience doesn't guarantee
safety. Often, experienced workers get accustomed to doing
things a certain way, but sometimes that accustomed way of
doing things can have hidden dangers. Just because those
short-cuts have not resulted in an accident in the past
doesn't guarantee that they won't next time.
Battery Explosion
Jump-Starting a Vehicle Can be Dangerous
People commonly jump-start vehicles with dead batteries,
both on and off the job. Jump-starting a vehicle is a
straightforward task that can be learned by anyone with the
desire to do so. However, because the task seems so simple, we
may overlook or discount the potential dangers involved, as
happened at the Hanford site.
What happened
On January 13, 1993, two contractor employees unsuccessfully
attempted to start a forklift. The weather was extremely cold at
the time, approximately 5.F, and the forklift had been stored in
an unheated area. Based on the symptoms they observed while
trying to start the vehicle, the workers reasonably concluded
that the forklift battery was dead and that the vehicle needed to
be jump-started. To do this, they used a welding machine.
The workers connected the welding machine to the battery and
switched it on, supplying approximately 135 amps at 12-15 volts
to the forklift battery. (Most automotive batteries are designed
for 50-60 cold cranking amps discharge, and charge rates of 10
Occupational Safety OBSERVER Page 5
amps or less are generally recommended.) Shortly after power was
applied the battery exploded, spraying battery electrolyte onto
the workers' outer clothing and the exposed areas of their faces.
Fortunately, both workers were wearing safety glasses at the time
of the incident and the amount of electrolyte that came in
contact with their skin was minimized. The workers immediately
washed their faces and another worker at the site called
emergency response personnel. The two workers were transported
to the Kadlec Medical Center where they were treated for minor
skin irritation caused by the electrolyte and released.
Results of the investigation
Investigation revealed three possible causes for the
explosion:
o An external spark might have ignited hydrogen gas being
released through the battery vents during the jump-start.
Hydrogen gas is created during the charging process and is
generated in increasing quantity with heat.
o The battery might have been frozen, which could have damaged
the battery's grid plates. The introduction of electricity
to the damaged grid plates could have caused an internal arc
that would have ignited hydrogen gas inside the battery.
o The battery vents might have been plugged by ice or other
debris. Lack of adequate venting could have caused a
pressure build-up inside the battery as hydrogen gas was
generated during the jump-start.
Investigators checked with the manufacturers of both the
forklift battery and the welding machine. The battery
manufacturer stated that a 135 amp/12-15 volt external source
applied to the battery for approximately a minute would generate
enough hydrogen gas to cause an explosion if the battery vents
were plugged. The company that manufactured the welding machine
did not generally recommend the use of its machines for
jump-starting, although models were available that specifically
indicated that they could be used for this purpose. The machine
used by the two workers was not one of these models.
Investigators concluded that the exact cause of the
explosion could not be determined. The most likely cause of the
accident appears to be related to a rapid build up of hydrogen
gas generated during the jump-start. The hydrogen was unable to
escape through vents, which were possibly plugged by ice.
Identified as contributory causes to the accident were the lack
of refresher training on hazards associated with jump-starting
and the lack of available written procedures.
Lessons learned
As simple as it may seem, jump-starting can be extremely
dangerous if proper procedures are not clearly understood and
correctly followed. Basic battery safety practices are addressed
in OSHA's Construction Standards (OSHA 29 CFR 1926.441); another
regulation, 29 CFR 1910.178(g), addresses forklift batteries
Page 6 Occupational Safety OBSERVER
specifically. When jump-starting a vehicle one should always:
o Perform the operation in a well-ventilated area.
o Ensure that the electrical source is within the rated
amperage of the battery being jumped.
o Visually ensure that cap vents are functional.
o Always make the last electrical connection, which almost
always produces a spark, at a point away from the potential
source of hydrogen (the battery).
o In extremely cold weather, visually check the "dead"
battery's cells before attempting a jump-start to ensure
that the electrolyte is not frozen. Note that many newer
batteries are the sealed type with no vent caps. They may
have a color- indicating "eye" which serves as a warning
when it is not safe to apply an amperage to the battery.
A reminder: Battery incidents of this type are not
restricted to the work site. They can happen anywhere!
They have happened just attempting to jump-start one car from
another.
Virginia Coal Mine
Miners Killed in Explosion
In day-to-day life, safety rules can sometimes be annoying.
They may seem to make a job more difficult and less pleasant.
But a tragic explosion in a Virginia coal mine shows how
disregard of these rules can lead to disaster.
What happened
In the early morning of December 7, 1992, a worker who was
400 feet inside the mine was picked up and thrown off his feet by
a blast of searing hot gases from an explosion much deeper in the
mine. He crawled to safety, having received second-degree burns
on his face and hands.
Miners were immediately fearful of what had happened to a
group of eight miners who were working a mile inside the mine.
Rescue efforts began immediately but proceeded slowly, as methane
levels in the mine were high and rescuers were afraid of setting
off another explosion. Three days after the explosion, the
rescuers found the bodies of seven of the eight miners. They had
died at their work stations, killed instantly by the blast. The
eighth body was recovered later.
Disregard of safety rules
The explosion was almost certainly a methane explosion.
Methane is an explosive gas that occurs naturally in coal mines.
Rescuers detected high levels of methane near the locations of
the bodies. Although the exact cause of the explosion has not
been determined, investigators found disturbing evidence at the
Occupational Safety OBSERVER Page 7
accident site Ä methane detectors had been disabled and they
found "the significant presence of cigarettes, both smoked and
unsmoked."
Methane detectors are installed on all underground mining
equipment. These detectors will shut the equipment off when
methane levels become dangerously high, so that the equipment
will not ignite the methane. Officials found that a methane
detector "was not functioning because of deliberate tampering."
The discovery of cigarettes was equally disturbing. Smoking
is prohibited in coal mines, and employers are even required to
body search miners for smoking materials before the miners enter
the mine.
Some lessons
Several lessons that are relevant to the DOE complex can be
drawn from this incident. Although the danger of methane in mines
is not pertinent to most DOE activities, a potentially explosive
atmosphere is a likelihood at industrial locations throughout the
DOE complex. Further, workers at some DOE sites are engaged in
the tunneling activities that are similar to mining and are
likely to be as hazardous.
There were several factors contributing to this accident,
the most critical being the disabled methane detector. Had this
detector been functioning, it would have warned miners of the
high levels of methane and they would have shut off equipment and
evacuated the mine or at least could have refrained from smoking.
The miners' disregard of the no-smoking policy is another
critical cause -- smoking is prohibited in a potentially
explosive atmosphere for a reason. The disabled detector and the
presence of cigarettes indicate a serious disregard for safety
rules.
Some questions about the role of management can also be
raised. Although the attitude of management towards safety in
this particular instance is not known, workers' casual attitudes
towards safety often flourish when management emphasizes
production over safety, either explicitly or implicitly. It is
not enough for managers to state that there is a safety policy Ä
they must actively implement and enforce the safety policy, and
continuously reinforce the workers' understanding of the
rationale behind safety rules.
Lack of Cooling
Inadequate Lockout/Tagout Leads to Fire
Periodic maintenance of equipment and systems is necessary
to keep everything operating within design specifications, but
many times during maintenance various valves, switches, and
circuits are either shut or de-energized. Specific
lockout/tagout procedures are used to ensure safety both when
equipment is out of service and when it is returned to service.
The recent fire at the Component Design and Integration Facility,
which is located at the Mountain States Energy site in Butte,
Montana, illustrates the serious dangers of not following
lockout/tagout procedures during maintenance activities.
Page 8 Occupational Safety OBSERVER
What happened
A fire occurred at the Component Design and Integration
Facility on January 21, 1993, causing approximately $15,000 in
damage. The fire started in and was confined to the afterburner
section of the Magneto Hydro-dynamics Facility (MHD), a test
facility for analyzing components used in the alternative
generation of electricity from coal. A water-cooled afterburner
was recently installed as a means of reducing carbon monoxide
emissions during tests. The fire began shortly after the test
started, when a loud roar was heard and smoke appeared in the
test bay. The fire was extinguished when the flow of combustion
air was stopped and a nitrogen purge was activated.
Investigation results
Investigators examining the accident site discovered that
the afterburner cooling water supply and return valves were
closed. The valves appeared to have been shut during welding
operations to repair water pipe leaks and, apparently due to an
inadequate lockout/tagout program, the valves were not reopened
prior to the start-up of MHD. Lockout/tagout procedures, if
properly developed and implemented, would establish the proper
steps for returning systems to operational configurations once
repair/maintenance activity was completed. This is especially
important for safety or control systems such as cooling water.
DOE 5480.19, Chapter IX, contains the requirements for a
facility lockout/tagout program which meets the requirements of
various sections of 29 CFR 1910 and 29 CFR 1926. The program
would include a section on Release from Lockout and Tagout, which
requires that actions be taken to "ensure that nonessential items
have been removed and to ensure that machine or equipment
components are operationally intact." Lock and tag procedures
are designed not only to ensure safety of personnel while a piece
of equipment or process is out of service but to ensure a safe
return to service after work is complete.
Lessons learned
Based on the preliminary information available concerning
this accident, there are some lessons that apply to DOE sites:
o Lockout/tagout procedures should be developed and followed
during maintenance activities to ensure that the operational
status of equipment is clear, and that equipment has been
returned to in-service configuration before attempts are
made to operate the system.
o Equipment start-up procedures should include checklists that
enable operators to verify that all supporting systems are
operational. Such verification should include the review of
lockout/tagout logs to ensure that system line-up is
correct.
o Accidents or occurrences that may be considered relatively
minor and do not involve injuries may be important
indicators of lockout/tagout problems. Such incidents
Occupational Safety OBSERVER Page 9
should be examined closely to determine if there are
shortcomings in lockout/tagout procedures or their
implementation. Addressing shortcomings early may avoid
much more serious incidents later.
$5 Million Fine
Responsibility for Worker Safety Ignored
There is a certain amount of danger in almost everything we
do. But workers have the right to expect that they will not be
killed or seriously harmed on the job. It is every manager's
responsibility to ensure that employees and the public are
protected. As shown in the following accident, willful disregard
of safety rules by management can lead to aggressive enforcement
action Ä in this case, a $5 million fine levied by the Department
of Labor against a fertilizer manufacturer.
What happened
On July 28, 1992, an explosion occurred at an agricultural
fertilizer manufacturing facility in Louisiana, injuring three
workers and four private citizens. The blast, which could be
felt for ten miles, spread debris and released as much as 50,000
pounds of ammonia into the atmosphere. Despite police warnings
that advised residents to stay indoors, several motorists were
caught in the area and later complained of burning eyes and
respiratory problems. Four employees suffered from ammonia
inhalation, cuts, and burns.
Urea is a fertilizer product made from ammonia and carbon
dioxide. Urea is produced in a pressure vessel known as a
reactor. This incident occurred when the reactor exploded. The
process leading to the reactor explosion began with a hole
produced by a faulty weld inside the unit. The hole was in the
inner shell of the reactor and allowed carbamate, a volatile
by-product of the production process, to leak into and corrode
the outer containment vessel. The carbamate hardened and clogged
holes in the outer shell that play a key role in maintaining
reactor stability. Once these holes were clogged, intense
pressure built up and caused the explosion.
Results of the investigation
OSHA investigators identified numerous willful violations of
OSHA standards that led to over $5 million in proposed
penalties. Essentially, the plant failed to provide a work place
free from recognized hazards that could cause death or serious
physical harm, as required in Section 5(a)(1) of the Occupational
Safety and Health Act. According to OSHA, the leak went
undetected for some time because the vessel was not adequately
inspected to identify such potential hazards. When the leak was
identified a decision was made, with intentional disregard or
indifference to OSHA regulations, to continue to operate the
reactor without making repairs. Last year OSHA promulgated the
standard for Process Safety Management of Highly Hazardous
Substances (29 CFR 1910.119). This standard requires, where
greater than threshold quantities of hazardous substances are
Page 10 Occupational Safety OBSERVER
involved, system safety analyses, change analyses, and management
systems to prevent these types of accidents. DOE contractors
have been in the forefront of development of many of the
techniques in use. It is critical that these systems be
rigorously implemented.
Applying lessons learned to DOE sites
Although this incident did not occur at a DOE site, it
demonstrates that willfully disregarding OSHA standards can
seriously jeopardize employee and public safety. Managers have a
personal responsibility to ensure employee safety by addressing
potential hazards quickly. In this instance, the offending firm
was held financially accountable for its actions. A discussion
of the complex issues surrounding the financial and legal
accountability of DOE officials and contractors is well beyond
the scope of this newsletter; however, in general, managers and
individuals in all industries are being held increasingly
accountable for their actions by the courts.
Occupational Safety OBSERVER Page 11
DOE Order 5483.1A, dated June 1983, requires DOE compliance with
OSHA regulations, including those listed in the Observer.
The descriptions of the incidents included in this compendium are
based on information available at the time of publication.
Articles regarding DOE incidents are drawn from ORPS reports,
accident investigation reports, and interviews with site
personnel. The following ORPS reports were used in this issue:
Knowledge of material characteristics pays:
SAN--LBL-EHS-1992-0012
Jump-starting a vehicle can be dangerous:
RL--KEH-KEH-1993-0002
Inadequate lockout/tagout leads to fire:
ID--MSE-CDIF-1993-0002
The Occupational Safety Observer
is a publication of the
Office of Environment, Safety and Health.
For more information or corrections to the articles in this
issue, please contact:
Tom Kyriakakis
Operations Management Division (EH-32.1)
U.S. Department of Energy
Telephone: (301) 903-5516
For address changes and mailing list information, please contact:
John Everett
Fax: (206) 528-3552
Telephone: (206) 528-3246