An effective launch programme by the manufacturers emphasised that Halon 1211 was an all-purpose, efficient medium suitable for any class of fire due to:
- Its rapid knockdown
- Its efficiency in terms of the volume and weight
of medium required
- Its safe use in occupied areas and on electrical
- It being clean in use, with no residues to clean
up after the fire was extinguished
Most of these were reasonable claims but, in fact, Halon 1211 was not as good as some other extinguishers in dealing with Class A fires and its use outdoors could be less than effective. But in the right environment and correctly used Halon 1211 was a very useful addition to the armoury of the professional and non-professional firefighter particularly in aircraft, in the computer and telecommunications industries, with the military and a whole host of other applications in transport, hospitals and the emergency services.
The total number of Halon 1211 extinguishers produced is not known, certainly many hundreds of thousands. They quickly gained in popularity under the weight of promotional activity carried out by the manufacturer and the portable extinguisher producers. In some European countries, Halon 1211 extinguishers outsold all other types based on claims relating to their multi-purpose capability.
Since the 1960s, the use of Halon 1211 in portable extinguishers has been promoted as the answer for most fire fighting situations, why is this now not the case.
When the Montreal Protocol was signed in 1987, many UK manufacturers took the decision to withdraw halon 1211 extinguishers from their product ranges immediately and to concentrate on other products. This action has substantially limited the number of such extinguishers in use and thereby minimised the problem of complying with the Montreal Protocol.
The European Council regulation 2037/2000 has the same implications for halon portable fire extinguishers as for fixed systems. This means that such extinguishers must not be used in the EC and the only exceptions are for use in some applications in civil aircraft, by the armed forces and by the emergency services for the protection of people.
There is no single direct replacement for halon 1211 for use in portable extinguishers. In order for an agent to be effective in portable extinguishers, it has to have certain properties, streaming for one, which enables it to be applied to the fire in the right concentrations and without vapourising too quickly.
The halocarbon’s (CFCs) and (HCFCs), were phased-out under the Montreal Protocol and a number of fire extinguishing halocarbon gases with zero ozone depletion potential (ODP) have been developed. The substitute gases used for firefighting purposes tend to be fluorinated gases belonging to a class of chemicals known as hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs).
These fluorinated gases are acceptable in the USA but are not fully acceptable in Europe. HFCs (hydrofluorocarbons) are acceptable in the USA and are not subject to the same restrictions in Europe as HCFC. Fluorinated gases do not damage the ozone layer like (CFCs) and (HCFCs), however they are powerful greenhouse gases, are generally long-lived and are included in the basket of gases under the Kyoto Protocol. The Kyoto Protocol placed legally binding requirements on signatories to reduce their carbon (and equivalent) emissions to below 1990 levels. Reducing fluorinated gas emissions will contribute towards meeting this obligation.
Europe has a policy to strictly control the use of these fluorinated gasses and this makes things very difficult for organisations using these gases. They are revising legislation to take account of this problems and this will make thing even more problematic in the future.
The case for economic and viable use of these in portable extinguishers still remains to be proved. Based on test results and ratings so far achieved, it is unlikely that customers will be willing to pay a premium for a product that performs only as well as the one it replaces.
The silver lining of this situation was that the voluntary withdrawal of portable halon extinguishers by most UK manufacturers at the end of the 1980s provided the impetus for a concentrated research and development effort into the more efficient use of existing agents. As a result, we have a whole new range of both water and foam extinguishers on the market which, through the development of chemical additives, are now far more efficient in firefighting terms.
These extinguishers are more effective when measured by their fire ratings, as well as being smaller (6-litre capacity instead of 9-litre), lighter, easier to handle and easier to use than any of the superseded two gallon water extinguishers, which were the basic tools industry for many years. Meanwhile, the simultaneous advances in nozzle design produce small droplet sizes that mean that such extinguishers can and do pass the 35kV dielectric test of the European Standard EN3 and are thus much safer to use on fires involving electrical equipment.
Evaluation of Alternatives to Halon Portable Fire Extinguishers
In this section possible alternatives to halon 1211 (BCF) in portable extinguishers are evaluated. Halon 1211 was a universal extinguisher that could be used on a wide range of flammable materials. The alternatives may not be suitable for all hazards in a particular location and it may be necessary to select more than one type. It is, therefore, essential that staff are trained properly to identify different types of extinguisher and to use them.
Professional advice should be sought where metal fires or fires involving gases may be a hazard.
Straight water is suitable for uses on fires of potentially smouldering materials such as wood, paper and fabrics which may leave glowing embers. Water is very efficient at cooling and so re-ignition is unlikely. The extinguishers have a long water jet that can be used to penetrate deep-seated fires.
This type of extinguisher is unsuitable for use on fires involving liquids or gases and in fact could spread a flammable liquid fuel. They should not be used on live electrical equipment, although some water extinguisher nozzles create a spray that will not conduct electricity.
‘Dry’ Water Mist Extinguishers
Water mist extinguishers are suitable for use on fires of wood, paper and fabrics, as well as burning liquids, kitchen fat and oil fires and gas fires. They are less effective than traditional water extinguishers on deep-seated fires.
‘Dry’ water mist extinguishers have been tested to 35kV and can be safely used on electrical equipment as the mist does not conduct electricity and the mist does not tend to form puddles.
Foam Spray Extinguishers
Aqueous Film Forming Foam (AFFF) spray is a general purpose extinguisher which may be used, with appropriate training, on a wide range of materials and flammable liquids.
Foam spray extinguishers are relatively light and can be considered as a replacement for halon 1211 extinguishers in vehicles. They are also suitable, with the correct fire rating, for public service vehicles. If certified with 35kV dielectrical test, foam extinguishers are safe on electrical fires (keep 1m safety distance).
Carbon Dioxide Extinguishers
Carbon dioxide (CO 2) may be used safely on a wide range of flammable liquids and materials including live electrical equipment. Care must be taken, however, to avoid contact with the discharge tube and horn to avoid frostbite because these parts get extremely cold in operation. Choose frost-free horns to avoid the risk of frostbite.
CO 2 is inexpensive but the containers are relatively heavy and the noise of the discharging gas can be alarming to the untrained user. Once the gas has dispersed re-ignition is a possibility.
Use of CO 2 is particularly recommended in telecommunication rooms, server rooms and similar applications on board ships.
General-purpose (ABC) dry powder is an extremely effective extinguisher giving rapid knockdown on flammable liquids. It may also be used on potentially smouldering materials and gas fires. The amount of clean up necessary after use is significant and there is a risk of inhalation and loss of visibility when used in a building.
Hydrofluorocarbons (HFCs) and Perfluorocarbons (PFCs).
HFC and PFC agents are restricted in the UK for use in portable extinguishers. It is not the policy of the fire industry to select fluorinated gases for use in this sector except in special circumstances and none are generally available in the market at present.
Staff must be provided with such training in the use of fire fighting equipment as appears necessary according to the role they may be expected to play in a fire emergency situation. Training should be provided by a competent person.
Portable fire extinguishers should be maintained at regular intervals and in accordance with the requirements of BS5306 Part 3. Excluded are the P50 maintenance-free extinguishers which only require a visual inspection by the owner.
This page is based on an article by David Bonnett chairman of the FETA. and you can get a copy of Phase out of Halons on pdf format.
Information on the substitution of halon in American http://www.epa.gov
After a review of Regulation (EC) No 2037/2000 on substances that deplete the ozone layer, which started at the end of 2006, the Commission presented a proposal on 1 August 2008 which recasts and amends the current legislation. for more information go to Protection of the ozone layer
Categories:Miscellaneous Fire Safety Issues
March 15, 2011[Last updated: December 29, 2012]