Hazards Associated with Commercial Cooking Operations

Report
Presentation
to
AIRM Technical Session
“Hazards Associated
with Commercial
Cooking Operations”
B. Bourke BSc MSc F.I.FireE.
???

+ hotel
Year 2011
Vilnius
Shopping
Mall (2009)
Understanding the
Hazards
 Multidimensional
 Human Factor, catering staff, building
management. (concerned with providing good
food)
 Food preparation area, range tops,
(concerned with food hygiene)
 Ventilation Equipment
 Maintenance (called in when something
doesn’t work)
These people are working with
heat and may not be aware of the
risks, for example of not
maintaining equipment.
What can be seen in a
restaurant
….What cannot be seen
What you do not see
Development of
Wet Chemical
 Innovation in commercial food
preparation techniques e.g.
Vegetable cooking oils.
Energy efficient appliances.
Leading to; Increased fire losses, failure
of ‘BC’ dry chemical.
 In Nov 1994 UL launched UL300
“Fire Testing of Fire Extinguishing
Systems for Protection of Restaurant
Cooking Areas”
 UL300 considers
Cooking Appliance Design
Cooking agent ignition characteristics
Worst case scenarios
Plenum Hood and Duct (existing
standard)
Classification of Fire
 BS 7937:2000 Classifies a class F fire as “fire in
cooking appliance that involves combustible
cooking media. (vegetable or animal oils and
fats)
(Class K in American system)
Suitability of extinguishing agent
 ABC Dry Powder has never been suitable
 UL fire testing demonstrates BC dry powder
is ineffective.
 EN3Pt 7 2007 considers it “hazardous for
powder and CO2 fire extinguishers to be
used on class F fires”.
Suitability of Fire Fighting
Equipment
Suitability of Fire Fighting
Equipment
Cooking
Range
Class F
What is
wrong
here?
Fire
fighting
equipment
Class ABC
&B
Incompatibility of Agents
Suitability of Fire Fighting
Equipment
Fire Blankets
Fire test described in BS:EN 1869:1997 allows
a 2 min pre burn. However, the gas supply is
isolated when the fuel ignites at approx 350to
370(AIT) Blanket is positioned and left in
place for 17 mins.
Many reports of fire blankets not working
possibly because the fire point would be in
excess of 370c or intervention has not been
immediate
Germany has banned the use of fire blankets
in commercial cooking operations.
Reported 70,000 fires in a 5 year period.
(Both commercial and domestic)
Origin and development of
standards
video
Origin and Development of
Standards
(Commercial cooking operations)
First considered by NFPA in 1946 (this
was mainly as a result of fire losses in the
newly emerging fast food industry)
This first standard became NFPA 96 (which
has undergone many revisions over the
years the latest being 2013)
Wet chemical extinguishing systems first
considered by NFPA in 1983 this became
NFPA17A( NFPA17 Dry Chemical)
When specifying it is the norm to quote
NFPA96/17A
Standards
NFPA 96:
“Standard for Ventilation Control and
fire Protection of Commercial Cooking
Operations” 2013 Ed.
NFPA 17A:
“Standard for Wet Chemical
Extinguishing Systems” 2009 Ed.
HVCA:
“Standard for Kitchen Ventilation
Systems DW171”
LPS 1223:
“Requirements and testing
procedures for LPCB Certification and
listing of fixed fire extinguishing
systems for catering equipment”
Testing of kitchen protection
equipment.
INTEO500763A
Artigo 194
No national standard (use
international standards)
VdS (Germany)
France
Portugal
Ireland
pr EN 16282 PT7
2011
“Equipment for commercial kitchens”
“Installation and use of fixed fire
suppression”
pr EN 50613
“Tests on devices for fire prevention
and suppression on hobs
.
ASHRAE
Guidance
LPC/FPA
Recommendations for fish and chip frying
ranges (16A)
LPC/FPA
Recommendations for cooking equipment
(16B)
NHS Estates
HTM 2025 Pts. 1 to 4 “Ventilation in
Healthcare premises”
Building
Services
Research &
information
Ass. (BSR1A)
LB65/94 “Ventilation of Kitchens”
Association
of British
Insurers
BSRIA
“Fire Risk Assessment Catering Extract
Ventilation”
HSE
“Maintenance, examination and testing of
local exhaust ventilation”
HVCA
TR/17, DW144, TR/19
BS 5588 PT9
“Code of practice for ventilation and air
conditioning ductwork”
International building Code
Fire Protection of
Commercial Cooking
Operations
 Fire Test Video
Fire Protection of
Commercial Cooking
Operations
Wet Chemical Fire Suppression
Distributors
 Ansul
 Range Guard
 Pyrochem
 Amerex
 Buckeye
 Nobel
Fire Protection of
Commercial Cooking
Operations
Components
 Exhaust System (canopy, filters,






ductwork)
Cooking Equipment
Maintenance
Fire Extinguishing System
Fire Fighting Equipment
Responsibility (rests with owner)
Training
Fire Protection of
Commercial Cooking
Operations
Access Panels
Fire Protection of
Commercial Cooking
Operations
Exhaust System
NB Fire Dampers not
permitted on exhaust
system. Yes on supply air.
Fire Protection of
Commercial Cooking
Operations
Types of Canopies (hoods)
Fire Protection of
Commercial Cooking
Operations
Types of Canopies (hoods)
Ventilated Ceiling
Typical Water Wash Plenums
Fire Protection of
Commercial Cooking
Operations
Fire Extinguishing System
 Shall be designed and installed in





accordance with NFPA 96/17A
Shall be both automatic and manual
Shall comply with UL300
Shall be provided with fuel shut off
Shall be provided with system
annunciation
Shall be installed by a certified
installer.
Myths Associated with
Wet Chemical Systems
System is stand alone
Does not need any interface
False
Wet chemical systems are a component of an
integrated system (NFPA 96)
Very basic fire safety principals are “upon
discovering a fire raise the alarm”
“where possible isolate power supply prior to
fighting the fire”
Wet chemical systems require annunciation and power
isolation
Fire Extinguishing Systems
Two Types
Single shot
Single shot
Continuous discharge
System comprises of a pre-determined
number of agent tank or tanks
sufficient to suppress and control a fire
in the protected area.
Appliance specific nozzle location
Fire Extinguishing Systems
Two Types
Overlapping Protection
Allows for relocation of cooking equipment
Non appliance specific
Fire Extinguishing Systems
Two Types
Continuous Discharge
Fire Extinguishing Systems
Two Types
Extinguishing Agent
Wet chemical (Trade name Ansulex)
“An aqueous solution of organic or inorganic salts or
a combination thereof that forms an extinguishing
agent” (NFPA17A)
Extinguishing Mechanism:
When applied results in a rapid spreading of
vapour suppressing foam on the fuel surface. The
foam extinguishes and secures the flame by
forming a barrier between the liquid fuel and
oxygen. The cooling effect lowers the temperature
(by at least 10 degrees C) and decreases fuel
vapour release (NFPA17A) (Saponification?)
Extinguishers shall use agents that
saponify, class B shall not be used.
Fire Protection of
Commercial Operations
How it works
Fire Extinguishing Systems
Nozzle Placement (Extract)
Fire Extinguishing Systems
Detection
Fire Extinguishing Systems
Nozzle Placement
(Appliance)
Fire Extinguishing Systems
Maintenance
 Semi Annual
 Annual
 10 Year Maintenance
VIDEO
Kitchen Fire Protection
Wet chemical suitability/ assessment
Project
Kitchen
Yes
No
Remarks
Enclosed
Open
e.g.Theatre style kitchen
Ductwork
Fire Rated
Protected
e.g.Via fire rated enclosure
No Protection
Interfaces
Fire Alarm
Power source/Gas,
Electrical
BMS
Wet chemical system
type
One Shot
Continuous Discharge
Additional Protection
e.g.Water mist enclosure
Building
Regulations
In this project the feature is for a full
view of the cooking operation.
Commercial cooking operations:
Are areas of special fire risk [TGD”B”]
“Desirable that kitchen be separated
from their associated restaurant by
fire resisting construction.”
(BS5588-6:1991)
Building
Regulations
Where it is impracticable to comply
fully with TGD”B” –
“Alternative solutions may be
considered”
“Compensating fire safety
measures may also be necessary”
e.g. Enhanced levels of life safety
protection
Traditionally fire resisting roller
shutters have been used to complete
the enclosure of the kitchen in the
event of a fire.
It was considered this solution was
not viable and so innovation has been
introduced.
AQ2000 Low Pressure
Water Misting System
Demonstration
Conclusion:
Hazards:
 The main hazard is the
ventilation canopy and extract
system (the core safety hazard)
 Cooking equipment is primarily
an ignition source
Other Factors:
 Poor cleaning of extract system
 Poor duct design i.e. 90 change in
direction, use of screws to secure
ductwork rather than welding or
liquid seal rivets.
 Structural construction and
conditions for the exhaust
ductwork i.e. horizontal ductwork
 Poor installation
Other Factors:
 Largely dependent on kitchen
working procedures e.g. oil
changes in fryers
 Cooking methods (woks can lead
to large flames) Higher cooking
temperatures leads to more
grease being transferred into
vapour.
 Dependant on temperature of
grease and grease residues.
Fire Containment Theory
Assumptions:
 Exhaust system of liquid-tight solidly welded
construction, is not heavily contaminated with
grease.
 Exhaust system extracts and drains the maximum
amount of grease in order to limit amount of fuel in
the ductwork.
 Exhaust system is regularly cleared.
 Fire containment is the responsibility of the exhaust
system not the fire suppression system (which
should be considered an extinguishing system)
 Grease fire can reach temps of 1260C
 Cooking area is enclosed in fire resisting
construction
Other Factors
Cooking operation is not code compliant
e.g.
 A la carte use of standards
(mismatch)
 No electrical interfaces (fire
alarm, power isolation)
 Incorrect fire fighting
equipment
 No training
 No fire safety management
Conclusions cont’d
 Fires in commercial cooking
operations (CCO) is a complex
subject
 Greater fire safety is achieved at
the design stage where all parties
are consulted and the information
is communicated to the builders
owners and users.
 Fire in CCO can be devastating so
we should be more pro-active in
prevention
Thank You
Questions

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