The enactment of the Fire Safety Order a year ago rekindled interest in portable extinguishers. Here Wolfgang Kruger sets out the latest product developments and examines the main issues.
Portable extinguishers have been around for the better part of 300 years, during which time they have developed from primitive, water-containing wooden barrels to sophisticated, engineered devices using a number of fire suppression agents. Along the way, they used several extinguishants such as carbon tetrachloride, that for various environmental, toxicological or performance reasons are no longer to be seen.
Modern portables, broadly speaking, are one of two types, and models are now available that are designed for clearly identified fire risks. The two types are stored pressure portables and gas cartridge extinguishers. The stored pressure extinguisher normally has a pressure gauge and, when the valve is opened, the pressure forces the extinguishant out of the extinguisher. A gas cartridge portable is operated by puncturing an internal gas cartridge which then pressurises the extinguisher, enabling the portable to operate in the same way as a stored-pressure extinguisher.
The particular fire risk classifications are set out in
BS EN 2: 1992 (Classification of fires), breaking down the risks into five classes. Briefly, Class A is flammable solid materials, such as wood, paper and cloth; Class B is flammable liquids, such as petrol, paraffin and paint, or liquefiable solids like grease and margarine. Class C fires involve gases that include propane, acetylene and butane; Class D is metals, for example, magnesium, aluminium, potassium, sodium, calcium and lithium; and Class F is cooking oil and fat fires.
Extinguishing options.
There are several ‘standard’ portables on the market today: water, foam, Carbon Dioxide, and dry powder. There is also a growing number of ‘special’ portables now available, each of which is for a specific fire risk.
Water portables are for use against Class A fires and their application is widespread throughout industry, commerce and agriculture. A recent new dimension to this type of portable has been the incorporation of anti-freeze protection – ideal when the portables are likely to be positioned outside on loading bays, forecourts or platforms. Foam extinguishers are suitable for both Class A and Class B fire risks. The majority use AFFF (Aqueous Film Forming Foam), which is well suited to fires involving petrol, tar, paints and oils.
CO2 portables are also suitable for Class B risks; they are also the most appropriate to use on electrical fires and so are commonly found protecting IT equipment. Powder portables are also appropriate for Class B risks, as well as Class A and Class C, so often are the most suitable choice for mixed risk environments.
However, where the market has seen significant progress recently is in the availability of risk-specific portables. While the ‘standard’ portables are ideal for general risks within each class of fire, they are not necessarily the most efficient solution for certain commodities and processes.
Recently, a portable that uses a specially developed powder extinguishant has been introduced to fight metal fires that typically can reach temperatures in excess of 2000 degrees C. Another example is an anti-magnetic portable, designed for hospitals and other locations where magnetic interference could potentially damage sensitive equipment, or put its performance in doubt or at risk. A powder portable that incorporates a special applicator has also been developed to fight coal dust fires, and a special extinguisher with a new spray nozzle that delivers the correct drop size and flow intensity has been introduced to fight sawdust fires.
Two other high risk areas have also recently seen developments that are making major strides towards improved fire safety – polar liquid fires and cooking oil and fat fires. While conventional foam portable extinguishers are deemed suitable for all Class B fires, in reality Class B fuels can be subdivided into non-polar solvents: hydrocarbons like high-octane petrol, aviation fuel and naphtha that will not mix with water; and polar solvents, such as acetone, methanol and methyl ethyl ketone that will mix with water. The latter group, polar solvents, do not respond to conventional foam extinguishants, so a new portable has been engineered that uses a special polar liquid foam agent.
Class F fires involving cooking oils and fats in commercial kitchens are another major fire risk – they can erupt into flames in an instant. Certainly, this is a type of fire that needs to be suppressed quickly, effectively and from a safe distance. A new portable extinguisher aimed at addressing these challenges has recently been unveiled. It incorporates a special nozzle applicator that enables the user to apply the portable’s wet chemical agent, while safely remaining three or four metres away from the fire.
Cause for concern.
With such a sophisticated offering, it is hardly surprising that portable extinguishers are judged to have the potential to make a major contribution towards fire safety. However, there are grounds for real concern about three key issues: quality, training and maintenance.
The European standard for portable extinguishers is EN 3: 1996, Part 3 and Part 6, and BS EN 3 Part 7: 2004, which replaced the earlier Parts 1, 2, 4 and 5. Part 3 addresses construction, resistance to pressure and mechanical tests, while Part 6 covers conformity and how to achieve certification. The newer Part 7 encompasses characteristics, performance requirements and test methods. Important though conformity with these standards is, it is only part of the quality assurance that specifiers and end users should be seeking, particularly in light of the responsibility that the Regulatory Reform (Fire Safety) Order now places on building owners and occupiers to ensure fire safety within their premises.
Certification by an approved, independent third-party accreditation organisation is essential to ensure that the extinguishers being offered meet, and continue to meet, the appropriate standards. These organisations – such as TUV and LPCB – are accredited by the United Kingdom Accreditation Service to ensure their credentials are of the highest international standards.
The importance of this third-party accreditation is that as a user, you can be sure that the extinguisher you buy today is built to exactly the same standard as the model that was originally tested and approved. If the extinguisher is from a producer that does not have this third-party accreditation there is, in reality, no guarantee that it is manufactured to the EN 3 standard. Earlier models from that supplier may have been, but re-sourcing steel and accepting a different specification, changing the inside or outside coating of the cylinder, or modifying the design are just examples of changes that can affect the performance of a portable extinguisher.
Another good quality indicator is BAFE (British Approvals for Fire Equipment) registration. While BAFE is not a certification body, it operates a single, independent registration scheme for products in the fire protection industry, for which third party certification has been considered appropriate. This includes the MP101: Manufacture of Portable Fire Extinguishers scheme, which has particular significance in the UK – unlike other EU countries where generally it is a legal requirement for portable fire extinguishers to be independently tested for both construction and performance to EN 3, this is not mandatory in the UK.
Performance in an emergency is, of course, the ultimate test; it is also not the time to discover that the extinguisher that has been selected fails to function properly. The Fire Safety Order places responsibility on a number of people to take “reasonable” steps to ensure fire safety. If these steps include the provision of portable extinguishers a court of law may take the view that, in light of the benefits of third-party approved being widely publicised, insisting on a third party approved product would, indeed, have been “reasonable”.
In essence, there are two types of portable extinguisher cylinders – deep-drawn cylinders and three-part cylinders. These are made from 1.5mm to 2.5mm thick FePO4 iron phosphate – interestingly, one of the few substances approved for use in organic farming. Both types have advantages and disadvantages, but both are subjected to the same testing regimes and have identical approval requirements. Currently, the deep-drawn technique is more common for cylinders manufactured in the UK and China – probably the largest “off-shore” supplier of portables into Europe – while three-part manufacture is more popular in the rest of the world.
Undoubtedly, the best portables are those where there is a 100% testing regime in the factory; where every cylinder and the entire extinguisher is pressure tested in accordance with the European Pressure Equipment Directive. Manufacture under ISO 9001: 2000 (Quality management systems) is a further indicator of a manufacturer’s maintenance of consistent quality standards.
Training
Training in the selection of the correct portable for a particular fire risk, and its use in an emergency are implicit in the Fire Safety Order. Any employee who may use a portable needs to understand the different types of fire, and why it is not merely a matter of grabbing the nearest extinguisher to tackle a blaze. The training has to empower the user to make intelligent decisions, and to do this they must understand the significance of the information carried on the extinguisher.
One particular aspect relates to the use of portables on electrical equipment, as many of them state they have been tested and are “safe to use on electrical equipment up to 1000V at one-metre distance”. Stated in this way – rather than saying that the extinguisher may “inadvertently be discharged on electrical equipment…”, as suggested by the Fire industry Association – could well imply to the uninitiated that the portable is recommended for electrical fires.
Maintenance of fire safety equipment is another key issue stressed in the Fire Safety Order. It is now a legal requirement for building owners and occupiers in England and Wales not only to properly maintain fire safety equipment and systems, but also to ensure that appropriate maintenance records are kept. Proper maintenance means entrusting it to suitably qualified people. The best assurance for this is to use a contractor that is BAFE-registered to the SP101/ST104 scheme. This is the Specification for Contract Maintenance of Portable Fire Extinguishers, which incorporates the Registered Fire Extinguisher Service Technicians Scheme. This will ensure that the work is carried out to BS 5306 Part 3 2003 (Fire extinguishing installations and equipment on premises. Code of practice for the inspection and maintenance of portable fire extinguishers).
Looking ahead.
There seems little doubt that portable extinguishers are going to play an even greater role in fire safety in the coming years, as a result of the Regulatory Reform (Fire Safety) Order and changes in the way fire brigades operate. The Fire and Rescue Act in 2004 means that brigades may not respond to all emergency calls within the same timescale, and they may also decide not to enter a burning building to fight the blaze – unless they believe the building is occupied. In these circumstances, the effective use of portable extinguishers may be all that stops a minor outbreak escalating into a property, business or life-threatening fire.
Although produced a few years ago, figures from the Fire Extinguishing Trades Association – now merged with the BFPSA to form the Fire Industry Association – suggest that portable extinguishers saved the British economy around GB pound 500 million every year and extinguished completely around 66,000 fires. So their contribution is undeniable.
Wolfgang Kruger is EMEA general sales manager for portable products at Tyco Safety Products fire suppression group. He is based at the TOTAL dedicated portables research and manufacturing facility in Neuruppin in Germany.
