Fire Safety Glossary

An addressable fire alarm system is a type of fire detection network in which every device — including detectors, call points, and sounders — is assigned a unique electronic address, enabling the fire alarm control panel to identify the exact location of an alarm or fault within a building.

An appliance is the general term used to describe all firefighting vehicles operated by UK fire and rescue services, including the standard pumping appliance (fire engine), aerial platforms, rescue tenders, and specialist vehicles such as hazardous materials units.

Approved Document B is the UK Building Regulations guidance document covering fire safety in the design and construction of new buildings and major extensions. It sets requirements for means of escape, internal fire spread, compartmentation, external fire spread, and access for the fire and rescue service, and references British Standards — including BS 5839 and BS 5266 — for specific technical requirements.

Aspirating smoke detection (ASD) is a high-sensitivity fire detection technology that actively draws air through a pipe network to a central detector, identifying smoke at concentrations far below the threshold of conventional point detectors. Also known as VESDA (Very Early Smoke Detection Apparatus), ASD is used in data centres, heritage buildings, and clean rooms, and must be designed to BS 5839-1.

An assembly point is a pre-designated location outside a building where occupants gather following an evacuation, enabling the fire warden to account for all staff, contractors, and visitors before the fire and rescue service arrives. Assembly points must be clearly signposted, identified in the fire emergency plan, and positioned away from the building and clear of vehicle access routes.

BAFE (British Approvals for Fire Equipment) is an independent third-party certification body that assesses fire protection companies and individuals against defined competence standards. BAFE schemes cover fire risk assessment (SP205), fire detection and alarm systems (SP203-1), portable extinguisher servicing (SP101), and emergency lighting (SP205-2), providing responsible persons with a verifiable measure of contractor competence recognised by fire and rescue authorities and insurers.

BS 5266 is the British Standard that governs the design, installation, and maintenance of emergency lighting systems in the UK. Part 1 (BS 5266-1) covers non-domestic premises and specifies categories of emergency lighting, minimum illuminance levels, battery duration requirements, testing regimes, and the competence expected of installers and maintenance engineers.

BS 5839 is the British Standard covering the design, installation, commissioning, and maintenance of fire detection and alarm systems in the UK. It is published by the British Standards Institution (BSI) and is divided into multiple parts, each covering specific building types or system components.

BS 9999 is the British Standard providing a comprehensive, risk-based code of practice for fire safety in the design, management, and use of buildings. It offers an alternative compliance route to Approved Document B, enabling greater design flexibility through detailed fire engineering analysis. BS 9999 covers compartmentation, means of escape, detection, suppression, and management procedures across the full lifetime of a building.

The Building Safety Act 2022 is major UK legislation establishing a new regulatory framework for the design, construction, and occupation of higher-risk buildings — defined as residential buildings of 18 metres or more, or at least 7 storeys. It created the Building Safety Regulator, introduced the Principal Accountable Person role, and significantly strengthened legal obligations around fire and structural safety in high-rise residential buildings.

A cavity barrier is a construction element installed within concealed voids — including ceiling spaces, roof voids, and wall cavities — to interrupt the paths along which fire and smoke can travel unseen and unimpeded. Cavity barriers form a critical part of a building's compartmentation strategy and must be present and undamaged, as identified during any fire risk assessment or compartmentation survey.

Co-responders are on-call firefighters who receive enhanced first-aid training and are dispatched alongside — or ahead of — the ambulance service to medical emergencies in their local communities. The scheme improves response times in rural areas where ambulance cover may be limited.

A CO2 (carbon dioxide) fire extinguisher is a portable firefighting device that discharges pressurised carbon dioxide gas to smother a fire by displacing oxygen. It leaves no residue, making it the preferred choice for electrical equipment, server rooms, and environments where contamination cannot be tolerated.

Community risk refers to the likelihood and potential impact of unwanted fire-related events occurring within a local area. Fire and rescue services assess community risk to prioritise prevention activity, allocate resources, and set response standards through their Integrated Risk Management Plans.

Compartmentation is the division of a building into fire-resisting cells using walls, floors, ceilings, and fire doors, designed to contain a fire within its compartment of origin for a specified period — typically 30 or 60 minutes. It is a core element of passive fire protection and is required in all non-domestic premises under Approved Document B and assessed through every fire risk assessment.

A conventional fire alarm system groups detectors and manual call points into fixed zones, each wired to the fire alarm control panel. When a device activates, the panel indicates the zone rather than the individual device. Conventional systems suit smaller, simpler buildings; larger or multi-zone premises typically require an addressable fire alarm system to meet the zone-size guidance in BS 5839.

A dry powder fire extinguisher discharges a fine chemical powder — typically mono-ammonium phosphate — to interrupt the combustion chain reaction. Effective on Class A, B, and C fires and live electrical equipment, it is identified by a blue label panel. Powder causes significant contamination and poor visibility, so its use in occupied buildings should be a last resort, per BS 5306-8.

An emergency exit sign is a self-illuminated or externally lit sign displaying the internationally recognised green running-man pictogram (BS ISO 7010 E001/E002) to indicate the direction of emergency escape routes and final exits. Signs must be visible from all points on the escape route, illuminated by the emergency lighting system, and maintained in accordance with BS 5266-1 and the Health and Safety (Safety Signs and Signals) Regulations 1996.

Emergency lighting is a lighting system that activates automatically on failure of the normal mains supply, providing sufficient illumination to enable safe evacuation of a building. UK law requires emergency lighting in all non-domestic premises, and it must be designed, installed, commissioned, and maintained in accordance with BS 5266-1 by a competent person.

An Emergency Response Standard is a risk-based target that sets the required response time and minimum number of firefighting staff to attend emergency incidents. Each UK fire and rescue service sets its own standards based on local risk assessment and publishes them in its Integrated Risk Management Plan.

An evacuation alert system (EAS) is an electronic system installed in higher-risk residential buildings that enables the fire and rescue service to issue targeted floor-by-floor evacuation alerts, directing residents to evacuate when the stay-put strategy is no longer safe. Required under the Fire Safety (England) Regulations 2022 for all residential buildings above 18 metres, EAS must comply with BS 8629 and be regularly tested and maintained.

A false alarm, or unwanted fire signal (UWFS), is an activation of a fire alarm system that does not result from a genuine fire. False alarms waste fire and rescue service resources, desensitise occupants to alarm signals, and reduce the effectiveness of the fire safety system. BS 5839-1 requires responsible persons and their engineers to investigate and address recurring false alarms by reviewing detector siting, type selection, and building processes.

An FD30 fire door is a fire door assembly rated to provide 30 minutes of fire resistance, tested in accordance with BS 476 Part 22 or EN 1634-1. FD30 doors are the minimum standard for most compartment boundaries in non-domestic premises and residential buildings, and require regular fire door inspection to confirm that seals, closers, gaps, and hardware remain compliant.

An FD60 fire door is a fire door assembly rated to provide 60 minutes of fire resistance, tested to BS 476 Part 22 or EN 1634-1. FD60 doors are specified in higher-risk locations — including protected stairwells in taller buildings, plant rooms, and storage areas with significant fire loads — and require regular inspection to confirm that seals, closers, glazing, and gaps remain compliant with BS 9999.

A fire alarm control panel (FACP) is the central processing unit of a fire alarm system, receiving signals from detectors and manual call points, triggering sounders, and indicating the zone or device address of an alarm or fault. It must be installed, commissioned, and maintained by a competent engineer in accordance with BS 5839-1:2017, and must be accessible to the fire and rescue service on arrival.

A fire alarm sounder is an audible warning device that activates when the fire alarm control panel receives an alarm signal, alerting occupants to evacuate. Under BS 5839-1, sounders must achieve a minimum 65 dB(A) at any sleeping position, or 5 dB above prevailing background noise, and must be positioned so that no part of the premises is outside their effective range.

A fire blanket is a sheet of fire-resistant material — typically woven fibreglass — used to smother small Class F fires involving burning cooking oils and fats, or to wrap around a person whose clothing is on fire. Required in commercial kitchens alongside a wet chemical extinguisher, fire blankets must meet BS EN 1869:2019 and must be replaced after any use — they are single-use devices.

Fire classes are the European classification system — Class A (solid combustibles), Class B (flammable liquids), Class C (flammable gases), Class D (combustible metals), and Class F (cooking oils and fats) — used to categorise fires by fuel type. Selecting the correct fire extinguisher requires matching the extinguishing agent to the fire class present in the premises, as specified in BS 5306-8.

A fire damper is a passive fire protection device fitted within ductwork where it passes through a compartment wall or floor, designed to close automatically in a fire and prevent flames and hot gases from spreading through the ventilation system. Fire dampers must be installed, tested, and maintained in accordance with BS EN 1366-2, and their operation must be verified as part of every fire risk assessment.

A fire door closer is a mechanical device fitted to a fire door that returns it automatically to the closed and latched position after each use, ensuring the door maintains its fire resistance rating and prevents smoke spread. A correctly functioning closer is a mandatory fitting on all self-closing fire doors and its operation is verified during every fire door inspection under BS 9999.

A fire door inspection is a formal assessment of a fire door assembly — including the door leaf, frame, seals, hardware, and signage — to verify that it will provide the specified fire resistance (typically 30 or 60 minutes) and close reliably in a fire, in accordance with relevant British Standards and the Regulatory Reform (Fire Safety) Order 2005.

A fire drill is a planned practice evacuation of a building conducted to test emergency procedures, familiarise occupants with evacuation routes and assembly points, and assess fire warden performance. Under the Regulatory Reform (Fire Safety) Order 2005 and BS 9999, fire drills should be held at least annually — more frequently for high-risk or high-turnover premises — and outcomes, including evacuation times and any failures, must be recorded.

A fire emergency plan is a documented set of procedures describing how occupants should respond to a fire alarm — including evacuation routes, assembly points, fire warden roles, arrangements for persons needing assistance (PEEPs), and how to call the fire and rescue service. Required under the Regulatory Reform (Fire Safety) Order 2005 and informed by the fire risk assessment, it must be communicated to all staff and reviewed regularly.

Fire prevention encompasses the activities undertaken by fire and rescue services to reduce the risk of fires occurring in homes and the wider community — including home fire safety visits, safe and well checks, education campaigns in schools, and targeted work with vulnerable individuals.

A fire resistance rating is the tested period — typically 30, 60, 90, or 120 minutes — for which a building element maintains load-bearing capacity (R), fire integrity (E), and thermal insulation (I) when exposed to a standardised fire. Ratings are specified by Approved Document B and BS 9999 for walls, floors, doors, and structural columns depending on building type, height, and occupancy.

A fire risk assessment is a systematic examination of a premises to identify fire hazards, evaluate the risk to people, and implement or recommend appropriate fire safety measures. All non-domestic premises must have a suitable and sufficient fire risk assessment under the Regulatory Reform (Fire Safety) Order 2005, carried out by a competent person and reviewed regularly — or whenever significant changes occur.

A fire risk assessor is a competent person engaged to carry out the fire risk assessment required by the Regulatory Reform (Fire Safety) Order 2005. Assessors must have sufficient training, experience, and knowledge of fire behaviour, building construction, and fire safety legislation to make reliable risk judgements. For higher-risk or complex premises, third-party accreditation through schemes such as BAFE SP205, IFE, or IFSM is strongly recommended.

The Fire Safety (England) Regulations 2022 are secondary legislation under the Fire Safety Act 2021, introducing additional fire safety duties for responsible persons of multi-occupied residential buildings in England from January 2023. Requirements include quarterly inspections of communal fire doors, provision of fire safety instructions to residents, and — for buildings above 18 metres — installation of an evacuation alert system and a building information box for the fire service.

The Fire Safety Act 2021 amended the Regulatory Reform (Fire Safety) Order 2005 to explicitly bring the structure, external walls (including cladding and balconies), and flat entrance doors of multi-occupied residential buildings within scope of fire safety law. The Act was introduced in direct response to findings from the Grenfell Tower fire inquiry and came into force in England and Wales in August 2021.

Fire safety protection is the activity undertaken by fire and rescue services to advise, inspect, and enforce fire safety standards in regulated premises, primarily under the Regulatory Reform (Fire Safety) Order 2005. Protection officers audit premises, issue enforcement notices, and prosecute non-compliant duty holders.

Fire safety signage refers to all mandatory signs in buildings communicating fire safety information — including emergency exit signs, fire action notices, fire door keep-shut signs, and fire extinguisher identification signs. Signs must conform to the symbols and colours specified in BS ISO 7010 and the Health and Safety (Safety Signs and Signals) Regulations 1996, and must be kept legible and unobstructed at all times.

Fire stopping is the sealing of penetrations in fire-resisting walls, floors, and ceilings — such as gaps around pipes, cables, ducts, and conduits — using approved materials that restore the required fire resistance rating. Inadequate or missing fire stopping is one of the most frequently cited failures identified during fire risk assessments and compartmentation surveys.

A fire warden (also called a fire marshal) is a designated person trained to assist with fire safety procedures in a workplace — including conducting evacuation drills, checking escape routes are clear, accounting for occupants at the assembly point, and supporting the responsible person in maintaining fire safety day-to-day. The Regulatory Reform (Fire Safety) Order 2005 requires the responsible person to appoint a sufficient number of competent, trained fire wardens.

Fire-resistant glazing is a glass or glazing assembly tested to provide fire resistance in doors, screens, partitions, and windows. It is rated for integrity (E) — resisting flame and hot gas passage — and optionally for insulation (EI) — also limiting heat transfer through the pane. It must be installed in certified assemblies, and its condition verified during fire door inspections and compartmentation surveys.

A foam fire extinguisher is a portable firefighting device that discharges AFFF (aqueous film-forming foam) to smother fires by forming a vapour-suppressing barrier and cooling the burning material. Effective on Class A (solid combustibles) and Class B (flammable liquids) fires, it is identified by a cream label panel and must be serviced annually under BS 5306-3.

Gaining entry is an initiative in which firefighters use specialist tools and techniques to assist the ambulance service in accessing properties where an unconscious, unresponsive, or vulnerable casualty is suspected to be inside. Firefighters are often able to reach the scene faster than ambulance crews in urban and rural areas.

Hazmat (hazardous materials) refers to chemicals, fuel spillages, biological agents, and other substances capable of causing serious harm to people, property, or the environment. UK fire services deploy specialist hazmat teams and equipment to contain spills, decontaminate casualties, and protect surrounding areas.

A heat detector is an automatic fire detection device that triggers an alarm when ambient temperature exceeds a fixed threshold (fixed-temperature type) or rises faster than a set rate (rate-of-rise type). Heat detectors are used in environments unsuitable for smoke detectors — such as kitchens, garages, and dusty plant rooms — and must be selected and maintained in accordance with BS 5839.

Higher-risk buildings (HRBs) are multi-occupied residential buildings that are 18 metres or more in height, or have at least 7 storeys, as defined by the Building Safety Act 2022. They are subject to the most stringent fire and building safety requirements in England, including registration with the Building Safety Regulator, appointment of a Principal Accountable Person, and compliance with the Fire Safety (England) Regulations 2022.

His Majesty's Inspectorate of Constabularies and Fire and Rescue Services (HMICFRS) is the independent body that assesses the effectiveness and efficiency of police forces and fire and rescue services in England, publishing inspection reports to hold services publicly accountable.

An incident is any event requiring attendance by the fire and rescue service, including fires, road traffic collisions, flooding, chemical spills, rescues, and medical emergencies. Incidents are categorised by type and severity to inform resource planning, response standards, and performance reporting.

An intumescent seal is a strip or compound fitted around the edges of a fire door that expands rapidly when exposed to heat, sealing the gap between the door leaf and frame to prevent the passage of fire and hot gases. Intumescent seals are a mandatory component of all fire door assemblies and their condition is checked as part of every fire door inspection under BS 9999.

Maintained emergency lighting is a system in which the emergency luminaires remain illuminated continuously during normal mains operation and stay on — powered by their batteries — when the mains supply fails. It is typically specified in cinemas, theatres, and venues where sudden darkness would cause panic, and must be designed and maintained in accordance with BS 5266-1.

A manual call point (MCP) is a fire alarm device that enables a person to raise the alarm manually by breaking a frangible element or pressing a button. Under BS 5839, call points must be sited at a maximum travel distance of 45 metres on every escape route, and each installed call point must be included in a regular weekly test rotation to confirm operability.

Means of escape are the designated routes — corridors, stairways, emergency exits, and final exit doors — by which building occupants can evacuate safely in a fire without obstruction. Adequate means of escape must be provided in all non-domestic premises under Approved Document B and the Regulatory Reform (Fire Safety) Order 2005, and must be identified and assessed in the fire risk assessment.

National Resilience is a UK government programme, established in 2003, providing fire and rescue services with specialist capabilities beyond normal local response — including mass decontamination, urban search and rescue, high-volume pumping, and logistics support for major or prolonged incidents.

Non-maintained emergency lighting is a system in which the emergency luminaires only illuminate when the normal mains power supply fails. It is the most common type of emergency lighting installed in offices, industrial premises, and commercial buildings, and must meet the illuminance and battery duration requirements of BS 5266-1.

An on-call firefighter is recruited to live or work within a set distance of a fire station and be available for call-out for a contracted number of hours each week. When paged, they respond to emergencies alongside wholetime colleagues and attend regular training sessions to maintain competence.

Operational risk is the risk of harm arising to fire service personnel, the public, or the environment while the fire service is carrying out its operational duties. Services manage operational risk through dynamic risk assessment, standard operating procedures, and pre-incident planning for known hazardous sites.

PAS 79 is the publicly available specification that defines best-practice guidance for fire risk assessors undertaking fire risk assessments in the UK. PAS 79-1:2020 covers non-complex premises and PAS 79-2:2020 covers housing. Both set out the expected methodology, content, and format of a fire risk assessment, and are widely referenced by enforcers and insurers when evaluating assessor competence.

Passive fire protection (PFP) comprises the structural and material elements built into a building to contain or slow the spread of fire and smoke without requiring activation — including compartmentation, fire doors, fire stopping, cavity barriers, and structural fire protection. PFP elements must comply with Approved Document B and are assessed as part of a fire risk assessment.

A Personal Emergency Evacuation Plan (PEEP) is an individualised plan prepared for a building occupant who may need additional assistance to evacuate safely — including people with mobility impairments, visual or hearing impairments, cognitive disabilities, or temporary injuries. PEEPs identify the person's specific evacuation needs, the assistance and equipment required, the persons who will provide support, and must be reviewed whenever circumstances change.

A primary fire is a fire in a building, vehicle, or outdoor structure — the most serious category used in Home Office fire statistics. Primary fires include all accidental and deliberate fires in occupied or unoccupied buildings, and fires in road vehicles, as distinct from smaller secondary fires.

The Regulatory Reform (Fire Safety) Order 2005 (RRO) is the primary fire safety legislation in England and Wales, applying to all non-domestic premises. It places a legal duty on the responsible person to carry out a fire risk assessment, implement appropriate fire safety measures, and maintain them effectively. Non-compliance can result in unlimited fines or imprisonment of up to two years.

Resilience, in a fire service context, is the capacity to sustain effective emergency response during major, prolonged, or concurrent incidents without degrading core service provision. It encompasses staffing depth, specialist equipment, mutual aid arrangements between services, and national resilience assets.

The responsible person is the individual or organisation with control of a non-domestic premises who, under the Regulatory Reform (Fire Safety) Order 2005, has a legal duty to take reasonable steps to reduce the risk of fire, protect occupants, and maintain fire safety measures — including carrying out or commissioning a suitable fire risk assessment.

Risk analysis is the systematic process of identifying, evaluating, and prioritising the risks that could affect a community or organisation. Fire services use risk analysis to develop their Integrated Risk Management Plans, determine resource deployment, and target prevention and protection activity where it will have the greatest impact.

A road traffic collision (RTC) is an incident on the public highway involving one or more vehicles. Fire services attend RTCs to make scenes safe, rescue trapped casualties using hydraulic rescue equipment, manage fuel spills, and support ambulance crews with medical intervention.

A secondary fire is a fire classified by the Home Office as generally smaller and lower risk than a primary fire — typically outdoor fires such as grassland, heathland, woodland, or refuse fires. While individually less serious, secondary fires still require attendance and can escalate into major incidents in dry conditions.

A smoke detector is an automatic fire detection device that senses airborne combustion particles and transmits an alarm signal to the fire alarm control panel. The two principal types are optical (photoelectric) detectors, suited to slow-smouldering fires, and ionisation detectors, suited to fast-flaming fires. Both types must be selected, positioned, and maintained in accordance with BS 5839.

A sprinkler system is an active fire suppression system consisting of a network of heat-sensitive sprinkler heads connected to a pressurised water supply. Individual heads activate only in the area of a fire, discharging water directly onto the burning material. Commercial systems are designed to BS EN 12845; residential systems to BS 9251. Sprinklers significantly reduce fire fatalities, injuries, and property loss.

Structural fire protection is the application of passive fire protection to load-bearing elements — including steel beams, columns, and concrete structures — to maintain their structural integrity for a specified period during a fire. Methods include intumescent coatings, spray-applied cementitious products, and fire-resistant board encasement, all specified to meet the fire resistance requirements of Approved Document B or BS EN 1993-1-2.

A waking watch is a temporary fire safety measure involving trained personnel patrolling a building continuously to detect fire and alert residents — typically imposed on multi-occupied residential buildings where cladding or passive fire protection defects pose an unacceptable life risk. It is an interim measure pending permanent remediation and can be replaced by a common fire alarm system once BS 5839-1 compliance is confirmed.

A water fire extinguisher is a portable firefighting device that discharges pressurised water to cool burning materials and prevent re-ignition. Identified by a red label panel, it is effective on Class A fires — solid combustibles such as wood, paper, and textiles — but must never be used on electrical fires, flammable liquids, or cooking oils. Annual servicing is required under BS 5306-3.

A wet chemical fire extinguisher is specifically designed for Class F fires involving burning cooking oils and fats. It discharges a fine mist of alkaline potassium solution that reacts with hot oil through saponification — forming a cooling, vapour-suppressing foam — and preventing dangerous re-ignition. Identified by a yellow label panel, it must be serviced annually under BS 5306-3.

A wholetime firefighter is a full-time operational member of the fire service who works a regular shift pattern — typically day shifts and night shifts — and is immediately available to respond to incidents while on duty. Wholetime stations provide 24-hour cover in areas of higher risk or population density.