24-05-2009, 08:47 AM
EDITED 18/04/2011 BY ANTHONY.B TO CORRECT & UPDATE
Choosing Fire Extinguishers
Fire extinguisher types and locations should be specified by a competent person as part of a fire risk assessment and the specification should be based around the benchmarks in BS 5306-8:2000 "Fire extinguishing installations and equipment on premises. Selection and installation of portable fire extinguishers. Code of practice" (currently under revision as of 2011)
Fuel sources are divided into different classifications based on their type - different fuels require different media
Class A: FLAMMABLE SOLIDS such as paper, wood, plastic etc
Class B: FLAMMABLE LIQUIDS/LIQUIFIABLE SOLIDS such as waxes, paraffin, petrol, oil etc
Class C: FLAMMABLE GASES such as propane, butane, methane etc
Class D: FLAMMABLE METALS such as aluminium, magnesium, titanium etc
Class F: Cooking OIL & FAT etc
Fires involving electrical equipment are not a separate Class as electricity is not a fuel - these fires will fall into classes A, B, C, D or F - HOWEVER an extinguisher that uses a non-conductive media should be selected for safety
Standard extinguishers
Water Jet Fire Extinguishers:
Used for Class A fires. Not suitable for Class B fires (spreads the fuel), Class C, Class D (explosive reaction), Class F (boil over), or where electricity is involved. Cools a fire well to prevent reignition
Water with Additive Extinguishers:
Used for Class A fires. Safe in the vicinity of electrical equipment up to 35kV. Not suitable for Class B fires (spreads the fuel), Class C, Class D (explosive reaction), Class F (boil over). Popular as smaller, lighter extinguishers can be used. Cools & penetrates a fire well to prevent reignition
Foam Spray Fire Extinguishers:
Used for Classes A & B fires. Safe in the vicinity of electrical equipment up to 35kV.Not suitable for Class C, Class D (explosive reaction), Class F (foam blanket is burnt back). Can be used on spilt flammable liquids to prevent a fire. Better on contained liquids & shallow spills with protection against reignition, not good for running fuel fires, also cools
ABC Dry Powder Fire Extinguishers:
Used for Class A, B & C fires and safe to use directly on electrical equipment.Not suitable for Class D (no effect), Class F (fire restrikes as soon as discharge stops). Good for rapid knockdown of liquid spills, but no protection against reignition. Very messy and can obscure vision/cause panic. Very damaging to electronic components. A "Jack of all trades - master of none"
CO2 Gas Fire Extinguishers:
Used for Class B fires and safe to use directly on electrical equipment. Not suitable for Class A (no cooling, fires restrike), Class D (no effect), or Class F (no effect). Leaves no residue and penetrates enclosed spaces well making it the best extinguisher for enclosed electrical equipment
Wet Chemical Fire Extinguishers:
Used for Class A & Class F fires. Safe in the vicinity of electrical equipment up to 35kV. Not suitable for Class B (no effect), Class C or Class D (explosive reaction)
Specialist extinguishers
Foam branchpipe extinguishers:
As for Foam Spray, but not safe in the vicinity of electrical equipment. Uses a low expansion branchpipe and is for deep contained liquid fires, often where an alcohol resistant foam is required
High Performance BC Powder extinguishers (Monnex, Purple K):
Special compounds for rapid extinction of Class B & C fires. Kilo for kilo they can extinguish greater sixes of fire compared to other types. Not suitable for Class A fires as they do not melt to form a crust over burning embers like ABC Powder
Class D Powder extinguishers
Special compounds that will flux over burning metals to seal over them and cut off the oxygen supply. Not suitable for other types of fire and very conductive so dangerous near electrical equipment.
ABF Foam extinguishers:
A recent development of special foam compounds that are often electrically safe and have a high Class B rating in addition to Class A & F
MRI compatible extinguishers
Specially constructed CO2 extinguishers totally free of magnetically sensitive components for use in MRI scanner rooms in hospitals
Clean Agent extinguishers
This type, used extensively in the US to replace Halon, is not often seen in portables in the UK and would be intended for high value electronics.
Halon extinguishers
In 2003 these became illegal under the The Environmental Protection (Controls on Ozone-Depleting Substances) Regulations 2002 except for a few exceptions such as the Police, Armed Services and Aircraft
Colour Coding
In line with the colour coding system used before 1997 in the UK, extinguishers may be colour coded on up to 10% of their body area as follows (based on BS 7863:2009 Recommendations for colour coding to indicate the extinguishing media contained in portable fire extinguishers)
Water - Red
Foam - Pale Cream
Dry Powder - Blue
Carbon Dioxide (CO2) - Black
Clean Agent - Green
Wet Chemical - Canary Yellow
The rest of the extinguisher body should be red to comply with BSEN3, the current manufacturing standard, however it is legal to use fire extinguishers with an unpainted polished finish (for aesthetics) as long as they are CE marked as Pressure Directive compliant and are approved in a premises Fire Risk Assessment.
Fire extinguishers must be commissioned and serviced by a competent person in accordance with BS5306-3:2009 in order to ensure their safe condition and efficacy as well as demonstrate compliance with the maintenance requirements of the Regulatory Reform (Fire Safety) Order 2005
Choosing Fire Extinguishers
Fire extinguisher types and locations should be specified by a competent person as part of a fire risk assessment and the specification should be based around the benchmarks in BS 5306-8:2000 "Fire extinguishing installations and equipment on premises. Selection and installation of portable fire extinguishers. Code of practice" (currently under revision as of 2011)
Fuel sources are divided into different classifications based on their type - different fuels require different media
Class A: FLAMMABLE SOLIDS such as paper, wood, plastic etc
Class B: FLAMMABLE LIQUIDS/LIQUIFIABLE SOLIDS such as waxes, paraffin, petrol, oil etc
Class C: FLAMMABLE GASES such as propane, butane, methane etc
Class D: FLAMMABLE METALS such as aluminium, magnesium, titanium etc
Class F: Cooking OIL & FAT etc
Fires involving electrical equipment are not a separate Class as electricity is not a fuel - these fires will fall into classes A, B, C, D or F - HOWEVER an extinguisher that uses a non-conductive media should be selected for safety
Standard extinguishers
Water Jet Fire Extinguishers:
Used for Class A fires. Not suitable for Class B fires (spreads the fuel), Class C, Class D (explosive reaction), Class F (boil over), or where electricity is involved. Cools a fire well to prevent reignition
Water with Additive Extinguishers:
Used for Class A fires. Safe in the vicinity of electrical equipment up to 35kV. Not suitable for Class B fires (spreads the fuel), Class C, Class D (explosive reaction), Class F (boil over). Popular as smaller, lighter extinguishers can be used. Cools & penetrates a fire well to prevent reignition
Foam Spray Fire Extinguishers:
Used for Classes A & B fires. Safe in the vicinity of electrical equipment up to 35kV.Not suitable for Class C, Class D (explosive reaction), Class F (foam blanket is burnt back). Can be used on spilt flammable liquids to prevent a fire. Better on contained liquids & shallow spills with protection against reignition, not good for running fuel fires, also cools
ABC Dry Powder Fire Extinguishers:
Used for Class A, B & C fires and safe to use directly on electrical equipment.Not suitable for Class D (no effect), Class F (fire restrikes as soon as discharge stops). Good for rapid knockdown of liquid spills, but no protection against reignition. Very messy and can obscure vision/cause panic. Very damaging to electronic components. A "Jack of all trades - master of none"
CO2 Gas Fire Extinguishers:
Used for Class B fires and safe to use directly on electrical equipment. Not suitable for Class A (no cooling, fires restrike), Class D (no effect), or Class F (no effect). Leaves no residue and penetrates enclosed spaces well making it the best extinguisher for enclosed electrical equipment
Wet Chemical Fire Extinguishers:
Used for Class A & Class F fires. Safe in the vicinity of electrical equipment up to 35kV. Not suitable for Class B (no effect), Class C or Class D (explosive reaction)
Specialist extinguishers
Foam branchpipe extinguishers:
As for Foam Spray, but not safe in the vicinity of electrical equipment. Uses a low expansion branchpipe and is for deep contained liquid fires, often where an alcohol resistant foam is required
High Performance BC Powder extinguishers (Monnex, Purple K):
Special compounds for rapid extinction of Class B & C fires. Kilo for kilo they can extinguish greater sixes of fire compared to other types. Not suitable for Class A fires as they do not melt to form a crust over burning embers like ABC Powder
Class D Powder extinguishers
Special compounds that will flux over burning metals to seal over them and cut off the oxygen supply. Not suitable for other types of fire and very conductive so dangerous near electrical equipment.
ABF Foam extinguishers:
A recent development of special foam compounds that are often electrically safe and have a high Class B rating in addition to Class A & F
MRI compatible extinguishers
Specially constructed CO2 extinguishers totally free of magnetically sensitive components for use in MRI scanner rooms in hospitals
Clean Agent extinguishers
This type, used extensively in the US to replace Halon, is not often seen in portables in the UK and would be intended for high value electronics.
Halon extinguishers
In 2003 these became illegal under the The Environmental Protection (Controls on Ozone-Depleting Substances) Regulations 2002 except for a few exceptions such as the Police, Armed Services and Aircraft
Colour Coding
In line with the colour coding system used before 1997 in the UK, extinguishers may be colour coded on up to 10% of their body area as follows (based on BS 7863:2009 Recommendations for colour coding to indicate the extinguishing media contained in portable fire extinguishers)
Water - Red
Foam - Pale Cream
Dry Powder - Blue
Carbon Dioxide (CO2) - Black
Clean Agent - Green
Wet Chemical - Canary Yellow
The rest of the extinguisher body should be red to comply with BSEN3, the current manufacturing standard, however it is legal to use fire extinguishers with an unpainted polished finish (for aesthetics) as long as they are CE marked as Pressure Directive compliant and are approved in a premises Fire Risk Assessment.
Fire extinguishers must be commissioned and serviced by a competent person in accordance with BS5306-3:2009 in order to ensure their safe condition and efficacy as well as demonstrate compliance with the maintenance requirements of the Regulatory Reform (Fire Safety) Order 2005