1(a) Sources of ignition
Virtually every workplace contains potential sources of ignition, although if they do not involve naked flames they may not be perceived as such. Some hazards, such as ovens and soldering irons, may be obvious and present a continual threat while others, such as blowlamps being used by contractors, may be transient or only pose a problem in case of malfunction or misuse.
Light bulbs are often overlooked but are almost always present and generally will not pose a risk if used correctly for the purpose that was intended. If, however, piles of paper in a stationery store are left in contact with a bulb then a fire may result. The same danger exists in the case of fluorescent light tubes where there is an additional danger of the fitting overheating if a fault should occur in the circuitry. A flickering tube may indicate that such a fault exists.
Similarly, most forms of convector heaters are quite safe in normal operation but may cause a fire if covered, for example to dry wet clothing.
The most common sources of heat in the workplace include:
- Flames or sparks from a work process such as welding, cutting, grinding, or the use of a hot air gun
- Electrical equipment
- Frictional heat
- Electrostatic discharges
- Ovens, kilns, open hearths, furnaces or incinerators
- Boilers, engines and other oil burning equipment
- Matches, lighters, candles and smoking materials
- Open gas flames and gas burning equipment
- Light bulbs and fluorescent tubes if too close to combustible materials
- Electrical extension leads and adapters
- Faulty or damaged wiring or electrical equipment
- Portable heaters
- Cooking equipment, including deep fat fryers
The list above is by no means exhaustive and is provided merely as a guide.
1(b) Combustible materials
All of the combustible materials in, or forming part of, the premises should be identified and their hazard assessed. Some, such as wallpaper on the walls, should cause little concern, but others, especially those that may be easily ignited, may require action to be taken to eliminate, control or avoid the hazard.
Items to be considered include;
(i) Materials that form part of the business operations
- Large quantities of paper, including files, folders and contents of waste bins,
- Many plastic materials, especially foamed plastics,
- Packaging materials,
- Fabrics and clothing,
- Timber, hardboard, chipboard and similar products,
- Chemicals which may be combustible or react with other chemicals to produce heat,
- Display and exhibition materials,
Large numbers of videos or computer tapes have been found to be a particular hazard and purpose-designed storage for these items should be provided.
(ii) Furniture and furnishings
All new furniture purchased should comply with the Furniture and Furnishings (Fire) (Safety) Regulations 1988, but especially in older premises, there may be items still in use which predate this legislation. Other items, such as curtains, are not subject to these Regulations but should also be assessed regularly, together with the furniture, to ensure that they are in good repair, and are still appropriate for the area and the use to which they are put.
These items include;
- Upholstered benches and stools,
- Beds and bedding where there is sleeping accommodation,
- Wardrobes and dressing tables,
- Dining chairs and tables,
- Curtains, drapes and cushions,
- Artificial foliage, trees, shrubs and flowers,
- Desks and office furnishings,
Many companies wish to make a good impression on visitors when they first enter the building and are tempted to fit carpets in the reception area and perhaps elsewhere. Some carpets ignite readily and burn to produce large volumes of smoke and toxic gases. They are therefore not suitable for use on escape routes. New floor coverings should comply with BS5287:Specification for the assessment and labelling of textile floor coverings tested to BS4790 (BS4790 is the method for determination of the effects of a small source of ignition on textile floor coverings (hot nut method)).
For similar reasons artificial plants are often used in public and reception areas. There is no British Standard for these and so they should be tested by removing a small piece of each component, taking the samples out of the building and applying a flame. Ignition is acceptable on the application of the flame, but on its removal the flaming should not spread beyond the area first ignited. It is suggested that items which produce flaming droplets are not placed on escape routes. Any foliage which is protected by fire resistant treatment may need to be tested and retreated after washing or cleaning. Dried flowers and grasses should not be sprayed with flammable substances such as hair lacquer as this would increase the likelihood of ignition and rate of fire spread.
(iii) Parts of the structure and fittings
It is often thought that buildings are constructed of non-combustible materials such as concrete and brick and therefore do not burn. While this may be true of the structure itself, apart from the case of wooden buildings, there is a wide spectrum of materials that are used in lining and separation that ignite comparatively readily and make a significant contribution to the development of a fire. They may also produce copious quantities of smoke and toxic gases which pose a threat to the occupants.
When carrying out a fire risk assessment consideration should be given to features such as;
- Combustible wall and ceiling linings,
- Large notice boards and tapestries,
- Timber shelving,
- Temporary room or office partitions,
- Plastic fluorescent-light diffusers,
- Unsuitable glazing
Unsuitable, non-fire-resistant, glazing can lead to fire spread from area to area or, in the immediate vicinity of some external routes, can pose a threat to life. Even fire-resistant glazing can, in some instances, radiate sufficient heat to be a potential threat to people attempting to escape. Glazing on or immediately adjacent to escape routes should therefore be assessed, as should glazing in compartment walls, and should be replaced if necessary.
1(c) Flammable liquids and gases
Large volumes of flammable liquids should be stored outside the premises in accordance to the guidelines published by the Health and Safety Executive. Only small volumes, adequate for the period of work, should be kept inside the buildings. Such liquids should be in sealed cans or safety containers where possible. The liquids to be considered are not only those available for the production process but must include any present for other uses, such as small volumes of petrol for the lawn mower and small amounts of solvents kept for cleaning purposes.
When carrying out the fire risk assessment consider;
- Petroleum products,
- Cooking oils,
- Motor oils, other lubricants and hydraulic fluids,
- Solvents and degreasing agents,
- Paints and thinners,
- Specialist chemicals used in production processes,
- Propane, butane, acetylene and other flammable gases in cylinders.
A note should also be made of aerosol cans, especially if large numbers of these are stored in the building.
1(d) Structural features that could lead to the spread of fire
The most serious of the structural features that lead to the spread of fire are unprotected openings in compartment walls, floors and ceilings which allow the spread of flames, hot gases and smoke into adjacent areas. Not all of the features might be as obvious as holes around services that can easily be seen and identified.
When the fire risk assessment is carried out care should therefore be taken to identify:
- Ducts without dampers,
- Flues and redundant chimneys,
- Voids behind panelling, above ceilings and below floors,
- Unstopped holes around services,
- Uncompartmented roof spaces,
- Warped and ill-fitting doors,
- Unprotected stairways,
- Unprotected areas resulting from changes of use.
In some instances, for example in listed historic buildings, specialist advice may need to be taken regarding the likely presence of some of these features.
In some industrial premises, openings may be protected by fire-resistant roller shutters or similar devices and these should be checked periodically to ensure that they operate correctly and run freely. The areas beneath the shutters should be checked regularly to ensure that no obstructions are present which could compromise the correct operation of the device,
Openings around conveyor belts pose particular problems which are addressed in ways appropriate to the building and the operations that are being carried out. The measures taken, should, however, be assessed and checked regularly.
Please note that this hazard spotting guide only covers the basics and should not be relied upon. We do, however, offer an extensive on-site fire risk assessment training course which teaches delegates how to perform assessments in their workplace. We also provide our own fire risk assessment service which includes both the completion of a fire risk assessment by one of our experts and a consultancy session to discuss the results.