Practical fire safety guidance for existing non-residential premises

Chapter 2: Assessment Of Fire Risk In Premises

44. Where fire safety law applies, it is a legal requirement to assess the premises to identify risk to persons from fire and to take fire safety measures. The assessment of risk should be specific to fire safety and to the specific premises concerned. A generic risk assessment will not be sufficient.

45. Fire safety risk assessment is a practical exercise aimed at evaluating the risk from fire and how to ensure the safety of persons in the event of fire. It involves an organised and methodical look at the premises, the activities within the premises, the type of occupants, the potential for a fire to occur and the harm it could cause to people. The existing fire safety measures are evaluated to establish whether they are adequate or if more requires to be done. In this respect, fire safety measures include not just physical measures, such as fire alarm systems and escape routes, but also standards of management.

46. The risk assessment process described in this chapter is shown in Figure 1.

Figure 1 Fire safety risk assessment process

Identify People at Risk

47. An assessment should be made of those persons at risk if a fire occurs within, or in the immediate vicinity of the premises. The number, characteristics and location of occupants, staff and other persons who frequent the premises should be identified. Disabilities should be taken into account along with people's familiarity with the premises. The inexperience, lack of awareness and immaturity of any young persons (under 18 years) employed, should also be considered.

Identify Potential Causes of Fire

Figure 2 Triangle of Fire

48. For a fire to start, three components are needed: a source of ignition; fuel; and oxygen. These components can be represented as the sides in a simple 'triangle of fire' model shown in Figure 2. If any one of these components is missing, a fire cannot start. Taking steps to avoid the three coming together will reduce the chance of a fire occurring, while reducing the quantity of oxygen (smothering) or fuel (starvation) may restrict the development of a fire.

49. The premises should be critically examined to identify potential ignition sources and materials that might fuel a fire and the circumstances which might allow a fire to start. Any previous fires should also be considered, as should indications of 'near misses', such as scorch marks on furniture or fittings, discoloured or charred electrical plugs and sockets or cigarette burns. Some general information and examples are given in Tables 1 to 3 at the end of this chapter and recommendations on controlling ignition sources are contained in Chapter 5.

Evaluate the Risk

50. The risk in the premises should be evaluated so that a judgement can be made on the adequacy of fire safety measures. Risk has two components: the likelihood that a fire may occur; and the potential for a fire to cause death or injury i.e. consequence. Both likelihood and consequence should be considered when assessing risk.

51. The likelihood of a fire starting will be low if there are few ignition sources, and if combustible materials are kept away from them.

52. Having considered the people likely to be at risk and the chances of a fire occurring, the consequences and extent of the risk to those people if a fire starts and spreads should be considered. In evaluating the risk to people, it is necessary to consider different situations and possible scenarios such as:

• fire starting on a lower floor affecting the escape of people on upper floors;
• the potential for fire to affect escape routes, particularly where there is a single escape route;
• fire developing in a space that people have to pass to escape from the building;
• fire or smoke spread through a building via routes such as vertical shafts, service ducts, service penetrations, ventilation systems, cavities, roof voids and open doors;
• fire and smoke spread through open areas such as atria and concourses;
• fire and smoke affecting the behaviour of occupants;
• the contribution to fire spread and development if dangerous substances are involved or if there is failure of work processes;
• fire and smoke spread into the premises from exterior fires;
• underground or tunnel fires where escape may involve upward travel above a fire;
• the potential for fire originating in the premises to pose a threat to persons in the surrounding area.

53. Additionally, where the building is in multi-occupancy, consider;

• the risk from a fire which may occur in communal parts or in another part of the building occupied by a different person; and
• the risk which a fire in the premises may pose to other occupiers of the building and any adjoining premises.

54. If there have been any previous fires in the premises, considering the circumstances and lessons learned may assist with evaluating risk.

Decide if Existing Fire Safety Measures are Adequate

55. A judgement needs to be made to determine whether the fire safety measures and fire safety arrangements are adequate or if more needs to be done to safeguard persons. The level of fire safety measures provided in premises should be proportionate to the level of risk posed to the safety of people and will therefore vary between different premises.

Formulate an Improvement Plan

56. Carrying out an assessment of the premises is not an end in itself. The outcome of the risk assessment needs to be acted upon; risks need to be controlled in a practical way and fire safety measures and arrangements need to be put in place.

57. Potential causes of fire identified should be avoided or removed, if reasonably practicable to do so. If they cannot be removed, measures should be taken to control the risks.

58. Where improvements to fire safety measures in premises are considered necessary as a result of assessment of risk, a plan for implementation of the improvements should be drawn up. The plan should have priorities and timescales for the completion of the action required.

59. Where improvements involve building work, the work should be carried out in accordance with Building Regulation procedures. In a listed building (a building of special architectural or historic interest included in a list compiled by the Scottish Ministers), alternatives to conventional fire safety measures may be appropriate. Guidance is available in Guide for Practitioners 7 Fire Safety Management in Traditional Buildings issued by Historic Scotland.

Record the Findings

60. Having carried out a fire safety risk assessment of the premises, fire safety law requires that certain information be recorded where five or more employees are employed by an employer (whether they are on the premises or not), or the premises is subject to licensing or registration, or an Alterations Notice has been issued requiring this. Chapter 4 contains recommendations in respect of record keeping.

Review the Assessment

61. The fire safety risk assessment should be reviewed regularly and also before any significant or relevant changes are made or if relevant safety issues arise. This will involve setting time aside to consider whether change has affected the risk and whether fire safety measures remain appropriate.

62. Where changes are proposed, the consequence to fire safety in the premises should be considered before the change is introduced. Changes that might prompt a review of the risk assessment include:

• a change in the number of people present or the characteristics of the occupants;
• changes to work procedures, including the introduction of new equipment;
• alterations to the building, including the internal layout; and
• the introduction or increase in the storage of dangerous substances.

63. A review should occur on becoming aware of shortcomings in fire safety measures; potential improvements; or if a fire or 'near miss' occurs which may indicate that the existing fire safety measures are inadequate. If the Fire and Rescue Service has attended a fire in the premises, its fire investigation findings may help inform a review.

64. Generally, reviews of a risk assessment should be carried out in-house by the premises management. This will reinforce ownership of fire safety management and assist in the development of relevant knowledge and of a fire safety culture. However where significant changes to premises have occurred, it may be advisable to seek specialist advice.

65. In respect of entertainment events, there may be a need for frequent reviews in cases such as where there are regular changes to premises or contents.

Table 1 - Ignition Sources

Potential ignition sources are those where sources of heat could get hot enough to ignite material. This could include: smokers' material - such as cigarettes, matches and lighters; naked flames - such as candles or open-flame equipment; heaters - fixed or portable; hot processes - such as cutting and welding or repair work; cooking equipment and lighting equipment; deliberate fire raising; electrical equipment or fixed installations; interaction of reactive chemicals; spontaneous ignition; and pyrotechnics and special effects. There are various ways to reduce potential sources of ignition, for example: replace naked flame and radiant heaters with a central heating system restrict the movement of, and provide guards for portable heaters; install, use and maintain electrical and mechanical equipment in accordance with the manufacturer's instructions; inspect and test electrical installations and equipment; ensure that the prohibition of smoking is enforced; take precautions to avoid deliberate fire-raising; and control the storage and use of pyrotechnics.

Table 2 - Fuel

Material which will burn and is in enough quantity may provide fuel for a fire. This includes contents, fixtures, fittings, structure, wall and ceiling linings and surfaces. Some examples of 'fuels' are: textiles, soft furnishings and clothing; flammable liquids and solvents, such as white spirit, methylated spirit, and adhesives; wood, paper, cardboard, plastics, cellular foam, rubber and upholstered furniture; waste and litter such as paper, packaging, wood shavings, off-cuts and dust; flammable gases such as liquefied petroleum gas ( LPG) and aerosol contents; hydrogen produced during battery charging; powdered materials or dusts (including materials not normally considered combustible but where, as a dust, they may be prone to dust explosions (examples are flour, animal feed and some metals); and dry vegetation. There are various ways to reduce the materials and substances which burn, and to separate them from ignition sources, for example: store flammable materials properly; remove combustible wall and ceiling linings, such as timber, polystyrene or carpeting (to reduce the surface rate of flame spread and smoke production); keep flammable or combustible materials in public areas to a minimum with stock in storage areas secure against fire raising; and control the build-up of combustible waste with proper disposal.

Table 3 - Oxygen

The main source of oxygen for a fire is in the air around us. Air supply can be by natural air flow through doors, windows and other openings; or mechanical air conditioning systems and air handling systems. Buildings may have a combination of sources capable of introducing or extracting air. Potential sources of oxygen supplied to a fire can be reduced by: closing doors and other openings; ensuring that doors are close fitting and, where appropriate, fitted with seals; and closing down ventilation equipment. The action may be a precaution taken in case a fire starts, such as keeping certain doors closed. In other cases, the action may take place once a fire is detected, such as when ventilation equipment is shut down (either manually or automatically), or when doors are closed, either manually or by the automatic release of hold-open devices. (This subject can be complex where an automatic smoke-control system is installed).