Real-World Explosions and Fire Examples:
In the July 2009 Newsletter article
took a snapshot look at some real-world example explosions involving chemicals
including fuels, several at industrial facilities.
We concluded that the PEAC
tool can be used by responders as a rapid first assessment of an incident or to
help recognize a potentially dangerous situation where things can go wrong and
what action can be taken.
We will examine three more real-world accidents in
Ammonium Perchlorate Explosion and Fire,
Henderson NV, 1988, 2 killed, 372 injured
United States Fire
Fire and Explosions at Rocket Fuel Plant, Henderson NV,
The United States Fire Administration,
created in 1974, is now part of the Department of Homeland Security.
The presence of a large quantity of a very
strong oxidizing agent (ammonium perchlorate) and fuels (high-density
polyethylene plastic containers used to contain the ammonium perchlorate; fiberglass;
also a 16-inch pressurized natural gas line) were the raw ingredients of a
chain of events leading to one of the worst industrial explosions in U.S.
Ammonium perchlorate is not normally explosive by itself at room
temperature, but the combination of a fuel and this oxidant results in an
explosive mixture even if the fuel is in trace amounts, and the chemical will
burn and may detonate at hot temperatures.
The incident occurred on 4 May 1988
at the Pacific Engineering Production Company of Nevada (PEPCON) plant in
You-Tube video clip taken by a television engineer less than
a second after the largest detonation (shock wave boundary line defined by
PEPCON was under contract to produce
ammonium perchlorate to be used as an oxidant for rocket fuel for the NASA
For reasons that this writer was unable to determine, PEPCON
continued production of ammonium perchlorate following the Space Shuttle 1986
Challenger disaster which resulted in suspension of space flights and
apparently little demand for the oxidant.
Without instructions from NASA to cease
production, PEPCON apparently continued to produce the oxidant storing it in
55-gallon high-density polyethylene drums after their existing aluminum storage
bins were filled to capacity.
The polyethylene drums were also used as part of
blending operations in meeting customer specifications.
At the time of the
disaster, on 4 May 1988, an estimated 4000 tons of ammonium perchlorate were
stored at the facility.
Another report estimated 10.5 million pounds.
ingredients for ammonium perchlorate manufacture, which included anhydrous
ammonia, hydrochloric acid, nitric acid shipped by rail and various chlorate
compounds were also at the site.
According to the United States Fire
Administration report, a fire originated around a drying process structure
between 11:30 to 11:40 AM on 4 May 1988.
The fire was initiated by use of a
welding torch to repair a damaged steel frame with fiberglass walls, which
caused the fiberglass to ignite.
The employees initially tried in vain to put
the fire out using a garden hose, but the flames quickly spread to an adjacent
storage area containing ammonium perchlorate in high-density polyethylene
This began a series of explosions starting at 10 to 20
minutes after ignition.
The 75 employees at the facility immediately evacuated
fleeing on foot and in cars.
The company Comptroller stayed behind to notify
the Clark County Fire Department and apparently assist evacuation.
of a nearby business, Kidd & Co. (produces marshmallows), also evacuated.
The quick evacuation from the area saved many lives before the major explosion
occurred, apparently when the 16-inch, 300 psig natural gas line directly under
the building containing the exploding ammonium perchlorate ruptured and “exploded”
with more ammonium perchlorate.
The only two deaths were the company
Comptroller who remained behind and a wheelchair-bound employee who was unable
to escape with no one providing assistance.
Most of the 372 people injured
were the result of flying glass.
The Fire Chief of the City of Henderson
approached the scene as employees were escaping.
At about 11:54 AM, the first
of two major explosions sent a shock wave that shattered the windows of his car
and showering him and his passenger with glass.
A fleeing driver of a heavily
damaged vehicle warned the Fire Chief of possible subsequent larger explosions;
the Fire Chief turned around and as he fled, the second explosion (four minutes
after the first explosion) nearly destroyed his car injuring him and his passenger
with flying glass.
A responding Henderson Fire Department vehicle was also
severely damaged with firefighters injured with flying glass.
firefighting units assisted the injured firemen at a staging area 1.5 miles
from the scene.
The explosions (seven in all) and fires were beyond their
The natural gas company shut off the natural gas
supply at 12:59 hours at a valve about one mile away.
Both the PEPCON facility and the Kidd
& Co. facility were completely destroyed by the explosions and fires.
explosions created a crater 15 feet deep and 200 feet long in the ammonium
perchlorate storage area.
The largest explosion was equivalent to 1000 tons of
Broken windows, doors blown off, and injuries from flying glass were
reported up to 10 miles away.
Moderate structural damage to buildings was
reported 3 miles away.
A Boeing 737 on final approach at McCarran
International Airport, 7 miles away, was buffeted by the shock wave; windows
were cracked and doors pushed open at the airport.
The incident caused over
$100 million in damages.
Bankrupted PEPCON settled for $71 million in a
courtroom battle involving dozens of insurance companies and over 50 law firms.
The PEAC tool carries a warning that
ammonium perchloride may explode in fires.
At ordinary temperatures, the
chemical will not burn, but the autoignition temperature is 240oC
(464oF), and the chemical may detonate.
The PEPCON facility was originally built
in the 1950’s in an isolated area well away from businesses and residential
But the Las Vegas metropolitan area grew, and eventually the town of
Henderson completely surrounded the facility while PEPCON remained in an
unincorporated area within Clark County.
The closest residential area was 1.5
miles away, but other businesses were closer.
The 16-inch natural gas pipeline
under the facility served Las Vegas.
The United States Fire Administration
report was critical of land use decisions.
The magnitude of the incident was
much greater than had been contemplated by urban planners.
Urban planner and
others in decision making capacity must be aware of worst case scenarios of
accidents that can happen.
The United States Fire Administration
report was also critical of hazardous materials training given to
Some aspects of hazardous materials training are very
specialized, and specialized expertise must be brought into play when unusual
or “exotic hazardous materials” are known to be present in a plant or
The “worst case” situation needs to be anticipated.
If the Fire Chief
had not been warned of possible big explosions at the last moment by fleeing
employees, the entire fire department could have been wiped out.
the Fire Chief made the correct decision to turn around and withdraw, and firefighters
set up a staging area 1.5 miles away to provide emergency treatment.
The industrial facility was not rebuilt.
The area was converted to residential development.
Hydroxylamine Explosion, Lehigh Co., PA,
1999, 5 Killed, 14 People Injured
This incident was investigated by the
Chemical Safety Board.
Their final report 1999-13-C-PA is available at
Photo by Tom
Volk, “The Morning Call”, used in the CSB Report
On 19 February 1999, at 8:14 PM, a process vessel containing
several hundred pounds of hydroxylamine exploded at the Concept Sciences.
Inc. (CSI) production facility in the Lehigh Valley Industrial Park near
Four CSI employees and one employee of an adjacent business
were killed; 14 people were injured including six firefighters.
occurred during startup of a new production facility for this chemical.
facility was located close to other commercial buildings which were damaged
by the blast.
The CSI process involved mixing
hydroxylamine sulfate with potassium hydroxide to produce hydroxylamine as a
30% slurry in water.
The precipitated potassium sulfate solids are then
filtered out leaving a 30% solution of hydroxylamine in water.
The next step
is to concentrate the solution to 50% using a vacuum distillation system and a
heat exchanger column operating at 140°F, followed by ion exchange purification
of the distillate, and final product packaging.
CSI also had a ready customer
for the 50% aqueous product (Ashland Chemical Company), who planned to use it
to strip process residues from integrated circuits.
The PEAC tool shows that hydroxylamine
is an unstable solid which may explode if heated and may detonate:
Laboratory distillation tests showed that
explosive solid crystals of hydroxylamine form if the solution concentration
exceeds 80%, and there is danger of fire and explosion if concentrations exceed
But CSI experienced problems with its heat exchange system in the
distillation column, and as a result, the concentration of hydroxylamine in the
charge tank (part of the distillation system) was recorded as 86% somewhere
between 7:00 and 7:15 PM on 19 February 1999.
At 7:45 PM, the distillation
column was shut down and cleaned with 30% hydroxylamine to wash away any
crystals that may have formed.
An engineering supervisor was called at his
home; he arrived at the facility at 8 PM.
Exactly what happened after that was
not clear, but at 8:14 PM the system exploded killing four CSI employees and
another person in a nearby business.
Two CSI employees survived the blast with
moderate to serious injuries.
Six firefighters and two security guards
suffered minor injuries.
Four people in a nearby building were also injured.
More people could have been injured or killed if it were not for the fact that
the explosion occurred on a Friday evening when most businesses were vacated.
at charge tank area, from CSB report
damaged 10 buildings within the Lehigh Valley Industrial Park and several
Total property damage was estimated between $3.5 and $4
Sections of the distillation equipment were thrown more than 1000
The end manway of the charge tank was thrown 200 feet.
approximately 6 feet wide, 26 feet long, and 16 inches deep was found in the
concrete floor where the charge tank had been located.
An OSHA contractor, Hazards Research
Corporation, investigating the accident estimated that the hydroxylamine in the
charge tank that exploded was equivalent to 667 pounds of TNT.
The CSB report stated that CSI knew of the
explosive hazards of 80% (and higher) hydroxylamine solution, but the plant was
the first of its kind in the U.S., and it was being brought on line for the
CSI apparently did not anticipate or allow for startup problems.
The CSB report noted another accident
which occurred later in Gunma, Japan, on 10 June 2000, at the Nissin Chemical
Nissin used a process similar to the CSI process for concentrating
hydroxylamine solution from 30% to 50%.
After a shutdown for 5 hours to
replace oil in a vacuum pump, the distillation was restarted.
concentration of hydroxylamine reached 85% 30 minutes after startup resulting
in an explosion which killed 4 people and injured 58 others.
(cited in CSB report and from various papers by Koseki available on the Internet)
demonstrated the explosive hazard of 85% hydroxylamine solution in water, and
while 50% hydroxylamine solution is usually “safe”, even a 50% solution could
be unstable if contaminated with several parts per million of iron.
On 9 November 2000, a Federal Grand Jury
indicted the president of CSI for alleged criminal violations of OSHA’s Process
Safety Management (PSM) standard (see 20 CFR Part 1910.119) which regulates
facilities with any process that contains 2500 or more pounds of hydroxylamine.
CSI contested the indictment, and on 5 setember 2001 as the result of the
defendant’s Motion to Dismiss, a U.S. District Court dismissed the case.
District Court said that OSHA’s PSM regulation is ambiguous as to whether CSI’s
hydroxylamine production process is covered, and informal interpretations
issued by OSHA are prohibited from being used against the defendant in a
The CSB report was critical of CSI for
failure to conduct a Process Safety Analysis in the location of the facility.
There were no standard engineering drawings, only basic sketches and process
Facility siting should consider all potential hazards (e.g.
fire, explosions toxic material release) to people and the environment.
is part of the process design.
The building itself where the explosion took
place was also shared by other businesses.
The CSB report also noted that CSI first
considered a site for the process in nearby Northampton County.
But on 30
March 1998, CSI was notified by the zoning officer that CSI would not be issued
a building permit or certificate of occupancy because the industrial park did
not permit a manufacturing facility “whose primary use involved chemical
manufacturing” without conditional approval.
No such conditions were imposed
for Handover Township in Lehigh County.
CSI provided Handover Township with
MSDSs for raw materials and finished products, but did not alert the township
as to process hazards.
Fire and Community Evacuation, Apex, North
Carolina, 2006, No deaths, 30 people Sought Medical attention
This incident was investigated by the
Chemical Safety Board.
Their final report 2007-01-1-NC is available at http://www.chemsafety.gov/assets/document/EQFinalReport.pdf
Photo from Wake County
Fire/Rescue Services used in CSB Report of destroyed Environmental Quality
Notice stacked drums.
The incident began at 9:38 PM on 5 October 2006
citizen driving past the Environmental Quality Company (EQ) hazardous waste facility
in Apex, North Carolina, called “911” to report a haze with a “strong
The Apex Fire Department responding to the call confirmed
the haze and chlorine odor, but could not determine immediately the source.
The Apex Fire Department Chief, acting as the Incident Commander, sent two
firefighter teams in personal protective equipment to investigate the source.
The firefighters located the source as
coming from one of the hazardous waste bays at the EQ facility.
itself was vacant and was protected by a chain-like fence with a padlocked
A small “sofa-sized” fire was in the bay.
However, the fire grew and
spread to the flammable hazardous liquid storage area in the next few minutes causing
55-gallon drums to ‘explode” sending fireballs hundreds of feet into the air.
The EQ facility eventually collapsed as seen in the photo.
About 30 people
including 13 first responders sought medical attention at local hospitals for
respiratory distress and nausea, although none were admitted.
Because of the unknown nature of the
chemicals, the Incident Commander chose to take only defensive actions, which
evacuation of about 3300 residences and the town hall, the fire station, and
town 911 center.
The evacuation order continued for 2 days because of possible
re-ignition and persistent smoke from the rubble.
control access to
roads leading into the evacuation area
stopping rail traffic
through the community
allowing the fire to
burn itself out
The North Carolina Department of
Environmental and Natural Resources (NCDENR) and the U.S. EPA began
investigations about five hours after the incident, including air quality
monitoring, and later, soil sampling.
On 17 November 2006, the NCDENR issued a
report that their environmental tests showed no offsite contamination.
Chemical Safety Board Investigations:
U.S. Chemical Safety Board (CSB) in their investigations found 22
other fire and chemical release incidents at hazardous waste facilities in the
United States in the five years prior to their 2008 report describing this EQ
Fifteen of these incidents involved fires and/or explosions
including one at an EQ facility in Romulus, Michigan, on 9 August 2005.
were chemical release-only incidents.
These 22 incidents included two deaths
and eight community evacuations
Photo, from Chemical Safety Board Report showing
generator with activation pin circled, in EQ rubble
While the CSB never determined the cause
of the EQ fire at Apex, North Carolina, the fire did originate in the bay
where oxidizers were stored.
Included in the oxidizer bay were unspent
aircraft oxygen generators and containers of solid chlorine-based pool
The CSB report said that if EQ used fire barriers (walls) to
OCTarate the segregated bays, the fire likely would have been contained
within the oxidizer bay and not spread to the bay where flammable hazardous
wastes were stored.
In addition, the EQ facility did not have an active fire
suppression system and relied only on five portable fire extinguishers for
control or to extinguish fires even though the facility stored hundreds of
drums of flammable and combustible materials.
The building was unoccupied at
the time of the incident.
The CSB report concluded that EQ had
limited contact with the Apex Fire Department prior to the fire, and EQ had not
provided the fire department with written information on the types, quantities,
and locations of hazardous materials in their facility.
While EPA regulations (e.g. 40 CFR 264.32)
on companies handling or treating hazardous waste require information be
provided to local authorities on the facility, its layout, and its hazards, the
regulations do not explicitly state what information should be written or if
updates are necessary.
OSHA regulations (29CFR 1910.1200) exclude hazardous
wastes from Material Safety Data Sheet (MSDS) requirements, and Community
Right-to-Know requirements exclude materials for which a MSDS is not required.
The APEX Fire Department inspected the EQ
However the EQ facility takes in and treats or recycles
many different kinds of hazardous wastes during the year meaning that the
particular situation in the oxidizer bin probably would not have been discovered
in the inspection.
The EQ facility was not rebuilt.
Role of the PEAC Tool
One common thread of the examples
presented is that first responders did not know what was being stored or used
at these facilities, or the hazards, and the owners/managers provided
inadequate information to the community.
Community Right-to-Know laws exist on
the books, and companies generally comply.
But there are gaps in the
regulations leaving companies with an uncertainty of how to comply.
EPA Off-site consequence analysis regulations only cover some chemicals and
fuels, and only if large quantities are used.
This leaves uncertainties for
responders as to what is present at a facility in case of an incident, if
owners/managers only comply with regulations as stated.
The PEAC tool is designed for inspectors
and responders to rapidly examine situations where accidents have or can
The inspections might be done by the local fire department,
by an insurance company, and also in-house.
What are the chemicals used and
where are they located?
Where are the oxidizers, fuels, acids, and caustics
What can happen if two or more chemicals come into contact, or are
water reactive, or may explode when heated?
What toxic gases may be given off?
What are the worst-case scenarios?