“Hazards Associated

with Commercial

Cooking Operations”

Presentation

to

Engineers Ireland

B. Bourke BSc MSc F.I.Fire E. Fire Eng. Tech.

MCIOB, Registered Building Surveyor.

???

+ hotel

Vilnius Shopping Mall (2009)

Year 2011

Year 2015

Year 2015

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 hazards, for example of not maintaining equipment.

What can be seen in a restaurant

….What cannot be seen

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:

VdS (Germany)

France

Portugal

Ireland

“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)

pr EN 16282 PT7

2011

“Equipment for commercial kitchens”

“Installation and use of fixed fire

suppression”

pr EN 50613

ASHRAE

“Tests on devices for fire prevention

and suppression on hobs

.

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)

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

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 code

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 cleaned.

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 1260C

Cooking area is enclosed in fire resisting

construction

Fire Protection of

Commercial Cooking

Operations

Types of Canopies (hoods)

Example 1

Fire Protection of

Commercial Cooking

Operations

Types of Canopies (hoods)

Ventilated Ceiling

Typical Water Wash Plenums

Fire Protection of

Commercial Cooking

Operations

Exhaust System (canopy, filters, ductwork)

Cooking Equipment

Maintenance

Fire Extinguishing System

Fire Fighting Equipment

Responsibility (rests with owner)

Training

Components

Fire Protection of

Commercial Cooking

Operations

Exhaust System

NB Fire Dampers not permitted on exhaust system. Yes on supply air.

Example 8

What you do not see

Example 6

Example 5

Fire Protection of

Commercial Cooking

Operations

Access Panels

Fire Protection of

Commercial Cooking

Operations

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.

Fire Extinguishing System

Fire Extinguishing

Systems

Extinguishing Agent

Extinguishers shall use agents that

saponify, class B shall not be used.

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?)

Other Factors

A la carte use of standards (mismatch)

No electrical interfaces (fire alarm, power isolation)

Incorrect fire fighting equipment

No training

No fire safety management

Cooking operation is not code compliant

e.g.

Fire Extinguishing Systems

Two Types

Single shot

Continuous discharge

Single shot

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

Suitability of Fire Fighting

Equipment

Incompatibility of Agents

What is

wrong

here?

Cooking

Range

Class F Fire

fighting

equipment

Class ABC

& B

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

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 350to

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 370c 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)

Fire Protection of

Commercial Operations

How it works

Fire Extinguishing Systems

Nozzle Placement

(Appliance)

Fire Extinguishing Systems

Nozzle Placement (Extract)

Fire Extinguishing Systems

Detection

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.

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

Fire Protection of

Commercial Cooking

Operations

Ansul

Range Guard

Pyrochem

Amerex

Buckeye

Nobel

Wet Chemical Fire Suppression

Distributors

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

Building

Regulations

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.

Semi Annual

Annual

10 Year Maintenance

Fire Extinguishing Systems

Maintenance

VIDEO

Example 2

Example 3

Example 4

Example 7