Fire
• Combustion process requires Fuel and
Oxidant, e.g.:
CH4 + 2O2  2H2O + CO2
• Flammability Limits: lowest and highest
concentration of fuel in air which will
support continuous combustion
• Depend on pressure, temperature, &c
Explosion
• Can be based on combustion:
– Wave of high pressure from rapid expansion
• Could be mechanical (e.g. bursting vessel)
• Explosives  Chemicals combining both
fuel and oxidant
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Hazard Parameters
• Volatility (vapor pressure and boiling point)
• Flashpoint
• Flammable vs. Combustible liquids (flash
point below or above 100 F, respectively)
• Autoignition temperature
• LFL/UFL
• LEL/UEL
Dust
Explosions
• Suspended particles of reactive
materials can combust/explode
like vapors and gases
• Coal dust in mines and fiber dust
in granaries are common
examples
• Particle surface area is an
important variable
A burning bag-house
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Example: Sugar Plant Explosion
AP: updated 7:07 p.m. ET, Fri., Feb. 8, 2008:
PORT WENTWORTH, Ga. - Volatile dust was
blamed Friday in an explosion that leveled a sugar
refinery, and crews pulled four bodies from
tunnels beneath the mangled mass of metal and
beams left by the blast. At least four people known
to be inside during the explosion were missing.
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Firefighters on Friday battle a fire at the Imperial Sugar Co., a day after a blast
ripped apart the plant on the Savannah River in Port Wentworth, Ga.
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Thu, Sep 24 2009:
ATLANTA (Reuters) - An explosion at Imperial
Sugar's plant near Savannah, Georgia, in 2008 that
killed 14 people was "entirely preventable," the
U.S. Chemical Safety Board (CSB) said in a report
on its investigation.
Imperial Sugar had been aware of the hazard of
combustible dust for decades before the accident
that also caused 36 injuries, mostly related to
burns and many of which were life-threatening…
CTA Acoustics Explosion
On February 20, 2003, an explosion and fire
damaged the CTA Acoustics manufacturing plant
in Corbin, Kentucky, fatally injuring seven
workers. The facility produced fiberglass
insulation for the automotive industry. CSB
investigators have found that the explosion was
fueled by resin dust accumulated in a production
area, likely ignited by flames from a
malfunctioning oven. The resin involved was a
phenolic binder used in producing fiberglass mats.
BP Plant Explosion
EHSToday (3/25/10): On March 23, 2005, tragedy struck
BP’s Texas City, Texas, refinery when a cloud of
hydrocarbon vapor exploded, killing 15 workers and
injuring more than 180 others. Perhaps the real tragedy is
that federal investigators believe that the accident – like so
many other workplace accidents – was entirely avoidable.
In 2005, following an investigation, OSHA hit BP with what
was, at that time, the largest fine ever: $21 million. A
February 2007 internal BP report commissioned by top BP
brass concluded that four members of management should
be held accountable for the blast.
BP (cont’d)
OSHA, however, didn’t let up on the company and in October
2009, the agency announced it was fining BP Products
North America Inc. again, this time for $87.4 million, “for
the company's failure to correct potential hazards faced by
employees.”
Victims of the blast and their family members sued the
company, and in 2007, BP acknowledged it had set aside
$1.6 billion to cover compensation claims related to the
blast.
Coors Plant Gas Explosion
Daily News-Record March 16, 2004:
ELKTON -- The Virginia Occupational Safety and
Health organization determined earlier this month
that last fall's deadly explosion at the Coors Brewing
Co.'s Shenandoah plant occurred because of on-site
hazards that Coors and E.A. Breeden Inc. failed to
address. The explosion killed two workers from E.A.
Breeden Inc. on Sept. 9, 2003. They were welding
atop [tanks containing methane.]
WHSV August 5, 2005:
The Coors Brewing Company has agreed to pay nearly
$71,000 in state fines stemming from a fatal
explosion at its Rockingham County plant in 2003.
Combustion Products
•
•
•
•
•
•
CO2 and CO
Particulates
SO2 and H2S
Hydrogen Chloride and Phosgene
Hydrogen Cyanide
Metals
Prevention
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•
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•
•
Leak control
Temperature control
Fuel deprivation (e.g. housekeeping)
Ventilation
Spark suppression
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Safe Working Procedures
Operational Analysis and Control (OAC)
Model
Analyse the Operation
What can cause harm?
What are you doing about it?
Is it enough?
Manage the Operation
What has to be done?
What resources do you need?
When does the operation need reviewed?
Effectiveness Review
Has the operation progressed as planned?
Detail the changes needed?
List the improvement actions?
Safe Working Procedures
Set your work objectives to include:
“...tasks/ activities are to be completed on time and in a manner that
does not cause harm to the employees, customers, other non-employees,
or the company/ organisation.”
Three key questions to start with are…
• What can cause a fire or explosion?
• What are you doing about it?
• Is it enough?
Safe Working Procedures
Know where the harm is;
Identify the key hazards & outcomes of exposure to fire or
explosion.
Source of Hazards
(non-exhaustive list)
Outcomes of exposure
(non-exhaustive list)
• Flammable materials & substances
•
•
•
•
•
•
•
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•
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•
Hot work
Ignition sources
Pressurised gas containers & vessels
Dust
Explosives
Explosive substances
Burns
Amputations
Noise induced deafness
Respiratory damage
Death
Emergency procedures
• Develop and communicate fire safety & bomb alert plans
• Have emergency fire fighting equipment (appropriate to hazards)
• Inspect and maintain fire fighting equipment
• Carry out periodic emergency evacuation drills
• involving all personnel and visitors
• Have fire safety and bomb alert notices
• clearly visible and easily understood
• multi-lingual
• Clearly mark all fire doors and escape routes
• Keep escape routes free from obstructions
Inspections, tests and maintenance
• Inspect and test all emergency equipment and
alarms
• Competent and authorized persons should carry out
inspections, tests and maintenance
• Maintenance may need to be carried out using a
permit to work system
• Keep a record of every inspection
Roles and Responsibilities
Duty Holders
Responsible for…
Managing Director
Ensuring compliance.
Safety Managers
Providing professional safety advice.
Business Activity Managers
Complying with the requirements.
Employees
Co-operating with the requirements.
Documentation
• Emergency Plans
• Emergency evacuation routes and warning notices
• Inspection log
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Fire Control
• Oxygen deprivation (e.g. CO2 and foam
extinguishers)
• Cooling to below ignition temperature (e.g.
water extinguishers)
• Training on use of extinguishers, and on
evacuation and damage control techniques
• Make sure available extinguishers match
likely fire hazard (class A-D)
Fire Classification
• Class A: ordinary combustible materials (e.g.
paper, wood, cloth, some rubber/plastic)
• Class B: flammable or combustible liquids,
gases, greases, and some rubber/plastic
• Class C: energized electrical equipment
• Class D: combustible metals (e.g. sodium,
magnesium, titanium, zirconium, lithium,
potassium)
Fire Diamond
• National Fire Protection Association (NFPA)
• Fire Diamond page
Fire Suppression
• All employees can help a little…
• …but for larger fires you need
pros
• Your site might have a “fire
brigade”
• If so, they should regularly train
and conduct drills
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Chemical Safety Board Video
http://www.csb.gov/investigations/detail.aspx?SID=35