Name Acronym Description
4x4 Response

A voluntary sector organisation that provides 4x4 vehicles and drivers to support emergency responders and voluntary organisations.

Access Control Point ACP

Controlled point through which essential non-emergency service personnel may gain access through the outer cordon

Accord européean relatif au transport international des marchandises Dangereuses par Route ADR

European agreements concerning the international carriage of dangerous goods by road.

Aerial fuels

Any fuel found at a height of more than 3.5 metres above the ground surface

Aeronautical rescue co- ordination centre ARCC

Royal Air Force facility at Kinloss responsible for the co-ordination of all airborne assets deployed in a rescue operation

Air Accidents Investigation Branch AAIB

An independent organisation embedded within the Department for Transport and responsible for the investigation of civil aircraft accidents and serious incidents within the UK.

Air management

The safe, effective and efficient management of available BA air supplies, by the individual BA wearer, the BA team leader and the person responsible for BA entry control, to ensure air/work evaluation and management to achieve BA wearer welfare and safety and operational objectives. This will necessarily involve managing the wear to meet any turn-around pressure, specified exit pressure and report to BA entry control point pressure criteria. This will more than likely include (for example) appropriate selection of BA wearers at the entry control point; the use of appropriate air consumption rate/s and duration tables; the use of telemetry; appropriate tasking and briefing of BA team/s; use of an appropriate turn-around pressure (where required); regular gauge readings by both the BA wearer and the team leader; and regular/ dynamic communications between the BA team and the entry control point, etc.

Aircraft Co-ordinator AirCO

Person who supervises the involvement of multiple aircraft in search and rescue operations

Aircraft post-crash management incident officer APCMIO

The primary police point of contact for liaison on military support requirements associated with the control and cordon of the site


An airstair is a set of steps built into an aircraft so that passengers may get on or off the aircraft


The common, secure digital radio system used by the emergency services and others in the resilience and security community. The system is based on the TETRA standards set.

All lane running ALR

The permanent conversion of the hard shoulder to a running lane on a motorway, whilst retaining the ability to dynamically control traffic.

Alpha (a) radiation a-radiation

Type of radiation involving the emission of an alpha particle from the nucleus of a radioactive atom. Can only travel a few centimetres in air.

Anaerobic digestion

Renewable energy process involving a collection of processes by which micro-organisms break down biodegradable material in the absence of oxygen to produce fuel (methane).


An acute allergic reaction to an antigen (e.g. a bee sting) to which the body has become hypersensitive

Animal welfare charities

This includes: 

  • RSPCA – Royal Society for the Prevention of Cruelty to Animals 

  • SSPCA – Scottish Society for the Prevention of Cruelty to Animals 

  • USPCA – Ulster Society for the Prevention of Cruelty to Animals 

Aqueous film-forming foam AFFF

Low-expansion foams such as AFFF are low-viscosity, mobile, and able to quickly cover large areas.

Areas of nature conservation ANC

Areas of nature conservation (ANC) are important sites designated and protected for being the best examples of their characteristic wildlife and geology.

Areas of Outstanding Natural Beauty AONB

In England, Wales and Northern Ireland, these are areas of land that have been identified for special protection to preserve their character and qualities because of their identified national importance. Refer to

Areas of Special Scientific Interest ASSI

Areas of Special Scientific Interest (ASSI) are important sites designated and protected for being the best examples of their characteristic wildlife and geology in Northern Ireland.

Association of Lowland Search and Rescue ASLAR

Charitable organisation dedicated to assisting the emergency services in looking for missing persons and to coordinate adequate arrangements for search and rescue in the lowland areas of the UK

ATEX directive ATEX

The ATEX directive consists of two EU directives describing what equipment and work environment is allowed in an environment with an explosive atmosphere. ATEX derives its name from the French title of the 94/9/EC directive: Appareils destinés à être utilisés en ATmosphères EXplosives. 

Auto-ignition temperature

Minimum temperature required to initiate or cause self-sustained combustion of material in the absence of any external source of ignition. 

Auxiliary power units APU

Usually a small engine carried on board an aircraft to provide an independent power source for such services as electrics, hydraulics, pneumatics, ventilation and air conditioning.


Avionics are the electronic systems used on aircraft, with systems including those for communication and navigation

Back burning

Back burning is a way of reducing the amount of flammable material during a controlled burn or wildfire by starting small fires along a manmade or natural firebreak in front of a main fire front


Water flowing back toward the dam face. Water in the backwash can be highly aerated. Aerated water may not support a person at the surface.

Base Controller (EA role)

An experienced EA member of staff responsible for overall incident control. They will be responsible
for directing the environmental response and providing support services to the site controller
and field staff at the incident. Other duties include mobilising external and internal resources
at a regional and area level.

BASIS Registration Limited

BASIS is an independent standards setting and auditing organisation for the pesticide, fertiliser and allied industries.
(Previously: British Agrochemical Standards Inspection Scheme)


A nominated person who will exercise command and control of forward operations within a given area of operations. Similar to the role of sector commander


Materials found at controlled sites such as laboratories. These materials would fall within the categorisation systems recognised throughout the industry.  

Biological agents 

Broad term used by industry to refer to both biohazards and biological risks (see biohazards and biological risks)  

Biological risks 

Materials found outside of controlled sites, such as blood at a road traffic incident.  

Boiling liquid expanding vapour explosion BLEVE

Boiling liquid in liquefied gas containers subject to heat that rapidly vaporises and expands, explosively bursting the container. 

Boundary starvation

Removing flammable materials or cargo on all six sides of a fire compartment to prevent fire spread, especially on board vessels.


Animals including domestic cattle, buffaloes, bison, yaks and antelopes 

British Association of Immediate Care Schemes BASICS

Professional association whose members are volunteer medical practitioners trained and equipped for the pre-hospital care of casualties at the scene of an accident or emergency


A hot spot in a fire


A large watertight chamber, open at the bottom, from which the water is kept out by air pressure and in which construction work may be carried out under water. 

Cardiopulmonary resuscitation CPR

A first aid technique which combines external cardiac massage with rescue breathing (inflating the lungs by using mouth-to-mouth resuscitation)

Casualty Clearing Officer

Ambulance officer who, in liaison with the Medical Incident Commander, ensures an efficient patient throughput at the Casualty Clearing Station

Casualty Clearing Station CasCS

Entity set up at the scene of an emergency by the ambulance service in liaison with the Medical Incident Commander to assess, triage and treat casualties and direct their evacuation

Casualty Information Unit

Element within the Casualty Bureau responsible for the recording of casualty data forwarded by Hospital Documentation Teams

Category 1 responder Cat 1

A person or body listed in Part 1 of Schedule 1 to the Civil Contingencies Act. These bodies are likely to be at the core of the response to most emergencies. As such, they are subject to the full range of civil protection duties in the Act.

Category 2 responder Cat 2

A person or body listed in Part 3 of Schedule 1 to the Civil Contingencies Act. These are co-operating responders who are less likely to be involved in the heart of multi-agency planning work, but will be heavily involved in preparing for incidents affecting their sectors. The Act requires them to co-operate and share information with other Category 1 and 2 responders.


Originally the term used to denote an overhead power line support wire derived from the curve a suspended wire naturally assumes under the force of gravity. Now adopted to mean the whole overhead line system.


The part of the track bed outside the ballast shoulder that is deliberately maintained lower than the sleeper bottom. The area immediately outside the ballast shoulder but not between tracks.


A chemical information database provided by the National Chemical Emergency Centre (NCEC).


CHEMET can be used to track the dispersion of a chemical release. Telephone advice is available on demand which will give a simple short-range prediction of the anticipated behaviour of the plume. In an incident involving hazardous chemicals, local fire and police services can contact the Met Office Environment Monitoring and Response Centre (EMARC). For small-scale events, EMARC produces meteorological guidance and a plume prediction as a chemical meteorology (CHEMET) report. For larger release events, such as the Buncefield Oil Depot fire, more-sophisticated plume modelling techniques are used.

Chemical abstracts service number CAS

A CAS registry number, also referred to as CASRN or CAS number, is a unique numerical identifier assigned by the Chemical Abstracts Service (CAS) to every chemical substance described in the open scientific literature, including organic and inorganic compounds, minerals, isotopes, alloys and non-structural materials.

Chemical and Pipelines Emergency Planning Liaison Group CAP EPLG

National policy forum chaired by the Health and Safety Executive, including representatives of the Local Government Association and emergency planners

Chemical, Biological, Radiological, Nuclear and Explosives CBRNE

Used to describe Chemical, Biological, Radiological, Nuclear and Explosive materials. CBRNE terrorism is the actual or threatened dispersal of CBRN material (either on their own or in combination with each other or with explosives), with deliberate criminal, malicious or murderous intent

Chemsafe Scheme CHEMSAFE

Scheme provided through the Chemical Industries Association to provide a rapid and co-ordinated response to minimise adverse effects to the public, property and the environment following a chemical distribution incident. 3 levels of service exist. 1 - information, 2 - advice at scene, 3 - practical assistance at scene.

Chest seal dressing

An airtight and watertight dressing for chest wounds

Classification, Labelling and Packaging of Substances and Mixtures Regulations  CLP 

Regulations that adopt the United Nations’ Globally Harmonised System (GHS) on classifying and labelling chemicals across all European Union countries, including the UK.  

Common Operating Picture COP

Single display of information collected from and shared by more than one agency or organisation that contributes to a common understanding of a situation and its associated hazards and risks along with the position of resources and other overlays of information that support individual and collective decision making

Common Recognised Information Picture CRIP

A single, authoritative strategic overview of an emergency or crisis that is developed according to a standard template and is intended for briefing and decision-support purposes.


Two or more diseases existing at the same time in the body

Compressed-air breathing apparatus CABA

Sometimes referred to as a self-contained breathing apparatus (SCBA) or simply breathing apparatus (BA), CABA is a device worn by rescue workers, firefighters and others to provide breathable air in an irrespirable atmosphere. 

Concept of Operations CONOPS

1. The statement of UK Central Government arrangements for responding to an Emergency.
2. A high level description of how a defined system will operate to achieve defined strategic objectives. CONOPS will establish the higher-level framework within which more specific, operational-level plans, protocols and procedures will be developed and implemented.

Confined space supervisor

Confined space supervisors should be given responsibility to make sure that the necessary precautions are taken, to check safety at each stage; they may need to remain present while work is underway. 

Confined vapour cloud explosion CVCE

Type of explosion in a liquefied hydrocarbon or other flammable gas cloud in a confined space, such as vessels, pipelines or buildings.


A conoid roof is a warped plane with a double curvature like the side of a cone. It is a popular design in modern architecture because of its visual drama and litheness, as well its typically non- traditional construction materials.


At the time, or as soon after the event as practicable

Control line

Control lines are constructed or natural barriers, including treated fire edges, which are used to control a fire. They can be constructed manually, mechanically or by applying water or retardants

Convection column

A rising column of pre-heated smoke, ash, particles and other debris produced by a fire

Critical National Infrastructure CNI

Critical National Infrastructure is a sub-set of critical infrastructure, and describes those elements of critical infrastructure which have been identified by Government as being of strategic national importance to essential service delivery. The loss or compromise of these assets would have a severe, widespread effect, impacting on a national scale.

Critical temperature

Temperature above which no amount of pressure can liquefy a gas. Does not relate to flammability or likelihood of explosion. 


A substance used to obtain temperatures far below the freezing point of water (less than -78oC).

Dead fuels

Fuels with no living tissue. The moisture content of dead fuels is mostly controlled by external weather conditions, such as relative humidity, precipitation, temperature, and solar radiation

Decontamination area

Area containing fire and rescue service (and possibly other emergency service) decontamination personnel, equipment and structures. It is a suitable area initially established outside the inner cordon, at first uncontaminated by the initial release, that becomes contaminated by the managed and controlled movement of people who require decontamination. Before decontamination commencing, the inner cordon will be adjusted to encompass the decontamination area.

Defence Accident Investigation Branch DAIB

Conducts impartial and expert no-blame safety investigations across defence organisations to ensure that causal factors are identified and understood as quickly as possible, and recommendations made to prevent recurrence and enhance safety, whilst preserving operational capability. (Formerly known as the Military Air Accident Investigation Branch (MilAAIB)

Defence Safety Authority DSA

Brings together the Defence Safety and Environment Authority (DSEA), the Military Aviation Authority (MAA) and the newly established Defence Fire Safety Regulator (DFSR) to form an independent authority that provides defence organisations with a single, independent focus for safety and environmental protection.

Definitive care

The completion of recommended medical treatment

Deliberate reconnaissance

Deliberate reconnaissance is distinct from scene assessment, which is a specific activity carried out before any formal structures being in place and as a necessary part of the initial response. Deliberate reconnaissance differs for each of the different agencies involved; for example, the police service may deploy for deliberate reconnaissance of a building or for the recovery of evidence, whereas the fire and rescue service will primarily deploy for substance analysis and identification.

Department for Environment, Food and Rural Affairs DEFRA

The Lead Government Department responsible for policy and regulations on the environment, food and rural affairs. Is also responsible for minimising the impact of emergencies on food production, fishing and farming.

Detection, Identification and Monitoring   DIM

A suite of Detection Identification and Monitoring equipment provided by the Government to fire and rescue services.  

Detection –the recognition of the presence of a CBRN material.   

Identification – the determination of which CBRN material is present.  

Monitoring – a continuous or periodic process of qualitatively or quantitatively determining the presence or absence of CBRN material.  

Direct Electronic Incident Transfer DEIT

Information can be transferred electronically to various agencies instantaneously providing a clear understanding of assistance required.


Process of leaving a ship, aircraft, or other vehicle.

Distribution network operators DNOs

Companies that own and operate the distribution network of towers and cables that deliver electricity from the national transmission network to homes and businesses. They do not sell electricity to consumers.


An instrument that records the total amount of gamma radiation received

Drain earth

A fixed or portable earthing device applied for purpose of protection against voltages from transmission towers or poles.

Drogue gun

A device that fires the initial parachute of an ejection seat in an aircraft


An unmanned aircraft system or an aircraft without a human pilot aboard. The flight of a drone may be controlled either by remote control from an operator or by onboard computers.

Duration table

Duration tables and/or calculators are provided as a guide to the average duration of a BA cylinder, based on the amount of air likely to be used by a BA wearer at a given incident type (ie normal fire service operations, or complex and/or strenuous BA wear involving sustained increased physical activity).


This should be requested where crews need to go within one metre of electrical traction current after the section has been isolated. This will remove the risk of any residual current remaining.

Ebb current

Once high tide occurs, the ebb current (outgoing tide) will start. This current moves away from the shore


An eddy is the swirling of a fluid and the reverse current created when the fluid flows past an obstacle. The moving fluid creates a space devoid of downstream-flowing fluid on the downstream side of the object. Fluid behind the obstacle flows into the void creating a swirl of fluid on each edge of the obstacle, followed by a short reverse flow of fluid behind the obstacle flowing upstream, toward the back of the obstacle. This phenomenon is most visible behind large
emergent rocks in swift-flowing rivers


Force or wind generated behind a jet engine, particularly on or before take-off when high or full power is set, but also when the aircraft is taxiing

Electro-explosive device EED

Any device that is initiated electrically to provide an explosive or pyrotechnic effect; such devices may be associated with, or form part of, an explosive armament store or may be an explosive component in an aircraft or equipment system, e.g. an explosive cartridge in a fire extinguisher or a miniature detonating cord (MDC)

Electronic Communications Resilience & Response Group EC-RRG

Body hosted by the Department for Business Innovation and Skills to plan for risk within the telecommunications sector and to facilitate co-operation in maintaining the national infrastructure in an emergency

Emergency action code EAC

Designed to cover the first vital step and gives an immediate indication of any actions that could be taken should it be necessary, without the use of reference materials or expert advice. (Also known as HAZCHEM).

Emergency Reference Levels ERLs

Quantitative criteria used to plan for the introduction of urgent countermeasures in the event of a nuclear emergency.

Emergency Services Collaboration Working Group

Working group comprising senior leaders from the Association of Ambulance Chief, Executives (AACE), Association of Chief Police Officers (ACPO), Association of Police and Crime Commissioners (APCC), College of Policing, Chief Fire Officers Association (CFOA) and the Local Government Association (LGA) on behalf of Fire Authorities

Emergency Traffic Management

Temporary traffic management using limited traffic management resources to: provide short term protection to those dealing with or involved in the incident, prevent escalation, protect and give direction to traffic approaching the scene, protect a scene of a crime, manage incident related congestion.

End of life vehicle site ELV

Commonly referred to as a scrapyard.

Enhanced Information Service for Emergency Calls EISEC

Instantly gives the control room operator location information details which may be used as a guide to the potential location of an emergency.


The perimeter of a building is referred to as an envelope

Environment Group EG

Body providing environmental and public health advice to responders in the event of a maritime pollution emergency

Environment Monitoring and Response Centre EMARC

The Met Office Environment Monitoring and Response Centre.


A horse or other member of the horse family, such as donkeys, mules, ponies and zebras 


Normal state of body water content; absence of absolute or relative hydration or dehydration.

European Aviation Safety Agency EASA

An agency of the European Union with regulatory and executive powers in the field of civilian

European Community Urgent Radiological Information Exchange ECURIE

Process for early notification of overseas nuclear accidents.

Exothermic oxidation

A chemical process that results in the release of heat

Explosive canopy

In aircraft fitted with ejection seats, the transparent enclosure (or canopy) over the cockpit is blown upwards and rearwards by an explosive charge

Explosive Ordnance Disposal EOD

The detection, identification, on-site evaluation, rendering safe, recovery and final disposal of unexploded explosives ordnance. It may also include explosives ordnance which has become hazardous by damage or deterioration.

Fall arrest

Prevention of a fall arrest system user from colliding with the ground or structure in a free fall. 

Fall Arrest

PPE which limits the extent of a fall.

Fall mitigation

Reduction in the severity of the hazards and risk associated with fall protection. 

Fall prevention

Prevention of a fall arrest system user from colliding with the ground or structure in a free fall.

Fall protection

Prevention of an operative from going into free fall by way of a rigid barrier or similar protection method. 

Fall restraint

Personal fall protection system that restricts the travel of the user away from potentially hazardous areas. 

Film-forming fluoroprotein FFFP

The type of foam that is better for cases where the burning fuel can form deeper pools

Fine fuels

Fast-drying dead fuels that are less than 6mm in diameter. Fine fuels ignite readily and are rapidly consumed by fire when dry. Examples of fine fuels include grass, leaves, ferns, mosses, pine needles and small twigs. When dried, fine fuels are referred to as 'flash fuels'

Fire intensity

The rate at which a fire releases energy in the form of heat, expressed as kilowatts per metre (kW/m) or kilojoules per meter per second (kJ). Fire intensity should not be confused with fire severity

Fire loading

The fire loading of a building or compartment is a way of establishing the potential severity of a hypothetical future fire. It is the heat output per unit floor area, often in kJ/m2, calculated from the calorific value of the materials present.

Fire point

Minimum temperature at which a mixture of gas and vapour and air continues to burn in an open container, when ignited. 


A measure to prevent the spread of fire.


FireMet is a weather system designed to provide fire and rescue service responders with the latest weather information to help them identify a safe approach when dealing with a major incident.


In vehicles or aircraft, a firewall is the part of the bodywork that separates the engine from the driver or pilot and passengers or crew

Fixed electrical ground power FEGP

A ground power supply for an aircraft parked at a stand, provided by means of a cable and plug.

Flame bending

The use of water sprays to bend a flame usually away from a risk or to protect personnel 

Flame height

Measurement of flame height is calculated perpendicular from ground level to the tip of the flame. Flame height will be less than flame length if flames are tilted due to wind or slope

Flame length

The total length of a flame measured from its base at ground level to the flame tip. Flame length will be greater than flame height if flames are tilted due to wind or slope

Flash point

Lowest temperature required to raise the vapour pressure of a liquid to a level where the vapour concentration in air near the surface of the liquid is within the flammable range; the air and vapour mixture will ignite in the presence of a suitable ignition source, usually a flame.

Fleet Diving Squadron FDS

RN bomb disposal unit, specialising in underwater Explosives Ordnance Disposal (EOD)

Force Incident Manager FIM

Tactical role within a Police service when responding to a major or critical incident.

Fourth rail

Occasionally a fourth rail between the running rails may be found which acts as a return circuit that may carry a current of up to 250 volts DC.

Fractional horsepower motor FHP

An electric motor with a rated output power of 746 watts or less.

Free surface effect

Free surface effect is the change in stability of a vessel caused by liquids moving about freely in a tank or hold. As a vessel rolls, liquids in tanks or breached compartments accentuate the roll by moving freely from side to side of the tank accumulating first on one side and then the other, and may adversely affect the stability of the ship.

Fuel break

An existing, planned change or discontinuity in fuel that will reduce the likelihood of combustion, fire intensity and/or the rate of firespread.


Airborne solid particles (usually less than 0.0001mm) that have condensed from the vapour state.

G-force limiter

Reduces the force of the seat belt above a certain threshold, in conjunction with belt tensioners

General aviation

A term used to describe all aircraft that weigh below 5700kg without fuel loading.

Girt bar

Metal bar that connects an emergency slide to the fuselage of an aircraft

Glasgow Coma Scale GCS

The Glasgow Coma Scale is a more in-depth way than AVPU used to assess a casualty's true level of responsiveness

Global Maritime Distress and Safety System GMDSS

Internationally agreed set of safety procedures, types of equipment, and communication protocols used to increase safety and make it easier to rescue distressed ships, boats and aircraft

Globally Harmonised System GHS

Globally Harmonized System of classification and labelling of chemicals. This is a UN scheme aiming to have, worldwide, the same criteria for; classifying chemicals according to their health, environmental and physical hazards; and hazard communication requirements for labelling and safety data sheets. The GHS is not a formal treaty, but instead is a non-legally binding international agreement. Therefore countries (or trading blocks) must create local or national legislation to implement the GHS.

Government departments responsible for the natural environment

This includes: 

  • Defra – Department for Environment Food & Rural Affairs 

  • DAERA – Department of Agriculture, Environment and Rural Affairs 

  • Scottish Government Agriculture and Rural Economy Directorate

Government Technical Advisor GTA

A senior official, usually from HSE’s Nuclear Directorate who attends the Strategic Co-ordination Centre to provide independent and authoritative advice to the police and other authorities handling the off-site response to a nuclear emergency.

Ground fire

A fire burning below the surface of the ground

Ground fuels

Any fuel below the surface fuel layer, normally within the soil. Examples of ground fuels include organic matter, tree roots, shrub roots, rotting wood and peat

Ground power unit GPU

A mobile power unit used by aircraft parked on the stand.


Bird faeces. 

Haemostatic agents

A variety of chemicals that are designed to stop the flow of blood from open vessels

Hazard identification number HIN

Used to generically describe the hazards associated to dangerous goods transported in accordance with the European transportation of dangerous goods regulations. Sometimes referred to as the Kemler code.

Hazard manager

A weather information interface provided by the Met Office. It provides a range of services that help authorities prepare for and respond to emergency incidents that are caused or influenced by the weather. It contains access to FireMet and CHEMET.

Hazardous Area Response Teams HART

Specially recruited and trained personnel who provide the ambulance response to major incidents involving hazardous materials, or which present hazardous environments, that have occurred as a result of an accident or have been caused deliberately.

Health and Safety Executive HSE

The Health and Safety Commission (HSC) and the HSE are responsible for the regulation of almost all the risks to health and safety arising from work activity in Great Britain.

Health and Safety Executive’s Nuclear Directorate HSE ND

HSE ND seeks to secure the protection of people and society from the hazards of the nuclear industry, by ensuring compliance with relevant legislation and by influencing the nuclear industry to create an excellent health, safety and security culture.It achieves this through:
• Working with other regulators and agencies
• Issuing licenses for various aspect of nuclear energy and materials
• Approving security arrangements within the industry and ensuring compliance with those arrangements
• Overseeing the UK’s international commitments on the peaceful use of nuclear energy
• Engaging with all stakeholders in an open and transparent way to inspire confidence in their work

Health Protection Agency HPA

The Agency identifies and responds to health hazards and emergencies caused by infectious disease, hazardous chemicals, poisons or radiation. It also makes sure the nation is ready for future threats to health that could happen naturally, accidentally or deliberately

Health Protection Agency Centre for Radiation, Chemical and Environmental Hazards HPA CRCE

A specialist centre of HPA which deals with radiation and chemical hazards and threats.

Health Protection Scotland HPS

Established by the Scottish Government to strengthen and co-ordinate health protection in Scotland.

Heat flux

Heat flux or thermal flux is the rate of heat energy transfer through a given surface per unit time. The SI derived unit of heat rate is joule per second, or watt. Heat flux density is the heat rate per unit area.

Helical flow

Found along a shoreline and is a corkscrew or spring-like current that is constantly rolling and pushing out into the laminar flow. This spiral water flow can sweep a person off their feet and push them into the main current or make swimming back to shore a challenge

Hexamethylene triperoxide diamine HMTD

Home-made explosive. 

High Rise Building

For Fire Service purposes a high rise building may be considered as a building that contains 5 floors above fire service access level or the height of the highest floor is more than 18m above that level.

High-expansion foam HX

High-expansion foams have an expansion ratio over 200 - 1000. They are suitable for enclosed spaces such as hangars, where quick filling is needed.

Highways Agency Managed Motorways

A managed motorway entails the permanent conversion of the hard shoulder to a running lane, whilst retaining the ability to dynamically control traffic

Horizontal fuel arrangement

A description of the distribution of fuels on the horizontal plane. The horizontal arrangement of fuels will influence the relative ease with which fire can spread horizontally across an area of land

Hydraulic injection

Hydraulic injection can be defined as the puncturing of the epidermis by a jet of a fluid under pressure

Immediate care practitioners

Highly trained doctors who provide their services in support of the ambulance service


(of liquids) not forming a homogeneous mixture when mixed

Improvised decontamination

Public decontamination using an immediately available method (wet or dry) before the use of specialist resources, such as blotting with paper tissues, washing in on-site facilities etc.

Improvised explosive device IED

Bomb constructed and deployed in ways other than in conventional military action. Improvised explosive devices have many forms but the most common group is peroxide explosives. 

Incident log

A timeline record of all significant decisions, actions and information received that is used to develop the incident operational plan and inform the de-briefing process.

Inflatable tubular system

A type of airbag system.

Infrastructure manager

An infrastructure manager is the person who is responsible for developing, maintaining, managing or operating an infrastructure. 

Inland water categories

Inland waters are classified as one of four categories:
Category A - narrow rivers and canals where the depth of water is generally less than 1.5 metres
Category B - wider rivers and canals where the depth of water is generally 1.5 metres or more and where the significant wave height could not be expected to exceed 0.6 metres at any time
Category C - tidal rivers, estuaries and large, deep lakes and lochs where the significant wave height could not be expected to exceed 1.2 metres at any time
Category D - tidal rivers and estuaries where the significant wave height could not be expected to exceed 2 metres at any time

Instrument landing system ILS

Electronic navigation system that provides guidance information to allow aircraft to approach and land, including during inclement weather conditions.

Integrated Risk Management Plan IRMP

The planning process and subsequent plan for a fire and rescue authority to demonstrate how its strategic direction meets the needs of the community

Inter-Agency Liaison Officer IALO or ILO

A Fire and Rescue Service officer who can advise and support Incident Commanders, Police, Medical, Military and other Government Agencies on the organisation’s operational capacity and capability to reduce risk and safely resolve incidents at where an attendance may be required. This will include major incidents, public order, domestic or any other situation that would benefit from the attendance of the ILO.

Interim decontamination

The use of standard fire and rescue service equipment to provide a planned and structured 'wet' decontamination process for members of the public.

International Atomic Energy Agency IAEA

The IAEA is the world´s centre of cooperation in the nuclear field. It was set up as the world´s "Atoms for Peace" organization in 1957 within the United Nations family. The Agency works with its Member States and multiple partners worldwide to promote safe, secure and peaceful nuclear technologies.

International Commission on Radiological Protection ICRP

An advisory body providing recommendations and guidance on radiation protection

International Maritime Dangerous Goods code IMDG

IMDG code is accepted as an international guideline to the safe transport or shipment of dangerous goods or hazardous materials by vessel on water.

International Maritime Organisation IMO

United Nations specialised agency that has developed international legislation dealing with the safety of life at sea and the prevention of pollution from ships.

International Nuclear & Radiological Event Scale INES

A tool for promptly communicating to the public in consistent terms the safety significance of reported nuclear and radiological incidents and accidents.

International ship-to-shore firefighting connection

An international shore connection to be used with marine firefighting systems during an emergency when a stricken ship has a system failure. International shore connections are portable universal couplings that permit connection of shipboard fire main systems between one ship and another or between a shore facility and a ship when their respective system threading is mismatched. Both the ship and the facility are expected to have a fitting such that in an
emergency can be attached to their respective fire hose and bolted together to permit charging
the ship's system.

Intrinsically safe

Intrinsically safe equipment has been designed and tested to not become an ignition source in a flammable atmosphere


Process of confining people to a space in an emergency, especially on board vessel.


An inverter (or power inverter) is an electronic device or circuitry that changes direct current (DC) to alternating current (AC) or vice versa


The process by which a neutral atom or molecule acquires or loses an electric charge. The production of ions.

Ionising radiation

Radiation that produces ionisation in matter.


An event where matter has been externally subjected to ionising radiation.

Jaw thrust

A professional technique used on a casualty, especially if there is suspected spinal injury, to open their airway

Joint Decision Model JDM

A decision model presented within the JESIP joint Doctrine and used to make analytical decisions

Joint Dynamic Hazard Assessment JDHA

An assessment of risk taking into account the requirements of all emergency response organisations present at an incident

Joint Service Co-ordination Group

Military body responsible for formal liaison (civil-military and tri-Service) within an Army Regional Brigade’s area

Ladder fuel

Fuels that provide vertical continuity that allow fire to move through the vertical fuel arrangement

Laminar flow

The fastest water travelling with no restrictions in a straight line down a river

Last known position LKP

During a search, clues will be gathered about the person. Occasionally, the clue will be solid enough to be reasonably certain the search subject left it. Since the LKP is more recent than the PLS, this provides a new starting point for the search.


This is any liquid that, in the course of passing through matter, extracts soluble or suspended solids or any other material through which it has passed.

Lethal dose  LD50

Amount of a material, given all at once, that causes the death of 50% (one half) of a group of test animals. The LD50 is one way to measure the short-term poisoning potential (acute toxicity) of a material.  

Lifeboat Operations Manager

Person with overall responsibility for a RNLI lifeboat station

Line blocked

This is a rail term for the line being blocked and is a stronger term than requesting trains to be stopped.

Liquefied natural gas LNG

Gases obtained from a natural gas field or by fractional distillation of petroleum crude oil (such as methane and ethane) and stored and transported as a liquefied refrigerated (cryogenic) gas. 

Liquefied petroleum gas LPG

Gases obtained from fractional distillation of petroleum crude oil such as propane, butane, which are stored and transported as a liquefied gas under pressure.


Member of the aircrew (civilian or military) who is in charge of planning and distributing cargo and passengers on an aircraft

Local emergency planning groups

Known as:
Local resilience forums (England and Wales)
Regional or local resilience partnerships (Scotland)
Emergency preparedness groups (Northern Ireland)

Lower explosive limit LEL

Lower explosive limit is the lowest concentration of vapour/gas in air at a given pressure and temperature that will propagate a flame when exposed to an ignition source.

Lower explosive limit LEL

Lowest concentration of vapour/gas in air at a given pressure and temperature that will propagate a flame when exposed to an ignition source. 

Lower flammable limit

Lowest concentration of vapour/gas in air at a given pressure and temperature that will propagate a flame when exposed to an ignition source. 

Machine-made mineral fibres MMMF

A wide range of materials that use the inherent strength and durability of woven fibres bonded together with resins. Previously known as Man-made mineral fibres

Major Accident Hazard Pipeline(s) MAH
pipelines; MAHP(s)

Supply systems for dangerous fluids as defined in schedule 2 of Pipeline Safety Regulations, which include high pressure natural gas, other gases, oils and chemicals

Man lock

An airlock that allows workers to pass in and out of spaces with differing air pressures, especially one providing access to and from a tunnel, shaft, or caisson in which the air is compressed. 

Manual in-line stabilisation

Maintaining the head and neck of an unconscious casualty in neutral alignment

Marine Response Centre MRC

Maritime and Coastguard Agency co-ordination centre for oil pollution incidents at sea that require a national response

Maritime Incident Response Group MIRG

Specialist fire and rescue service teams strategically located around the country, for response to emergencies at sea

Maritime Patrol Aircraft MPA

Long range military aircraft for detecting, locating, tracking, observing and, if necessary, attacking surface vessels and submarines

Maritime Rescue Co- ordination Centre MRCC

Her Majesty’s Coastguard regional centre overseeing and co-ordinating the search and rescue operations within a region

Maritime Rescue Sub Centre

Her Majesty’s Coastguard unit subordinate to a Maritime Rescue Coordination Centre

Maritime Safety Information MSI

Internationally agreed system for promulgating information on weather, sea conditions and navigational hazards

Master of Vessel

Captain, commander or first officer of a ship or person in charge of a vessel or craft

Media Technical Briefer MTB

Provided by the nuclear site operator to provide input to press conferences and media briefings ahead of the Government Technical Advisor’s arrival.

Medical Link Call

Service enabling a vessel or craft at sea to obtain medical advice from a qualified doctor, via radio or satellite

Military / MOD Coordinating Authority

Provides Government Liaison Officer in the event of an accident at a defence nuclear site.

Military Liaison Officer MLO

Officer appointed by the regional military headquarters to act as the point of contact within a civilian authority’s command and control structure

Miniature detonating cord MDC

May also be referred to as a linear cutting cord (LCC) or a mild detonating cord. This is an explosive cord around or within military aircraft canopies/escape systems that once operated will explode outwards, shattering the canopy material to allow the seat to pass through easily.


(of liquids) forming a homogeneous mixture when added together

Missing Persons Enquiry Unit

Element within the Casualty Bureau responsible for receiving enquiries from the public and recording details of missing person

Mobile operations manager MOM

Generally respond to any incident involving the safe operation of the railway. These people can then be appointed to become the rail incident officer (RIO) at incidents.

MOD Headquarters Defence Nuclear Emergency Organisation HQ DNEO

Provides advice on MOD on MOD operational policy and military advice to the Government crisis management organisation following an emergency, including one arising through terrorist acts, involving Defence nuclear assets.

Multi Agency Incident Transfer MAIT

Information can be transferred electronically to various agencies instantaneously providing a clear understanding of assistance required.

National Arrangements for Incidents Involving Radioactivity NAIR

A National advice scheme coordinated by Health Protection Agency to provide advice and assistance to the emergency services with incidents involving radioactivity where no formal contingency plans exist.

National Chemical Emergency Centre NCEC

The National Chemical Emergency Centre (NCEC) offers a 24-hour emergency hazardous materials response service that provides fast, trusted and up-to-the-minute advice to both the emergency services and businesses around the world. It is based in Harwell, Oxfordshire and operates under the CHEMSAFE scheme.

National frameworks NCAF

National Co-ordination and Advisory Framework - England
Fire and Rescue National Framework - Wales
Fire and Rescue Framework - Scotland
Corporate Plan and Annual Business Plan – Northern Ireland

National Scenic Areas NSA

In Scotland, sites identified with outstanding scenery that require special protection from inappropriate development. Refer to National Scenic Areas Scotland for more information

Natural Resources Wales

Natural Resources Wales is a Welsh Government sponsored body it was formed from a merger of the Countryside Council for Wales, Environment Agency Wales, and the Forestry Commission Wales, and also assumes some other roles formerly taken by Welsh Government. (Welsh: Cyfoeth Naturiol Cymru)

Nuclear Accident Response Organisation NARO

Ministry of Defence (MOD) agency responsible for response to an accident or incident, including one arising through terrorist acts, involving defence nuclear assets

Nuclear Emergency Planning Liaison Group NEPLG

A Forum which brings together, under Department of Energy and Climate Change (DECC) chairmanship, a wide range of organisation with interest in off-site planning for an emergency at civil and defence nuclear sites.


A bacterium, virus, or other microorganism that causes disease

Pneumatic caisson

Pneumatic caissons are sealed at the top and filled with compressed air to keep water and mud out at depth. An airlock allows access to the chamber. 

Polychlorinated biphenyls PCB

A group of manmade compounds that were widely used in electrical equipment, but which were banned at the end of the 1970s in many countries because of environmental concerns.

Precursor chemicals

Compounds that participate in a chemical reaction to produce another compound. 

Public Health England PHE

Public Health England is an executive agency of the Department of Health in the United Kingdom. Its formation came as a result of reorganisation of the National Health Service (NHS) in England outlined in the Health and Social Care Act 2012. It took on the role of the Health Protection Agency, the National Treatment Agency for Substance Misuse and a number of other health bodies


A company limited by guarantee that offers mutual assistance in the event of a transport accident involving radioactive materials belonging to a RADSAFE member.

RAF regional liaison officer RAFRLO

The RAFRLO liaises with the civilian emergency services and local authorities to provide a conduit between the military, civilian agencies and other government departments as required.

Rail Accident Investigation Branch RAIB

The independent railway accident investigation organisation for the UK. It investigates railway accidents on the UK's railways to improve safety, not to establish blame.

Rail Incident Commander RIC

Strategic level commander appointed by Network Rail for incidents involving infrastructure controlled by Network Rail

Railway Safety Directorate

Part of the Office of Rail Regulation (ORR) responsible for generally monitoring the effectiveness of the safety regime on Britain's railways. It also conducts research on rail safety and reports on trends in railway incidents and accidents.

Railways Incident Officer RIO

Representative of the railways sent to the site of an incident involving or impacting on the railways

Ram air turbine RAT

A small turbine that is connected to a hydraulic pump, or electrical generator, installed in an aircraft and used as a power source

Reglement International concernant le transport de marchandises Dangereuses par chemin de fer RID

European regulations concerning the international carriage of dangerous goods by rail 2015.

River left

Refers to the left side of a river looking downstream

River right

Refers to the right side of a river looking downstream



Run at caution

Train drivers are informed that there is an incident on or near the railway. The driver will reduce their speed in the area to ensure stopping safely.

Running rails

The rails that the vehicle's wheels are guided along


Identified as a curvature in the landscape formed between two areas of higher ground

Safe air

An environment where the air is breathable and will not be harmful without the use of respiratory protection. (see also clean air)

Safety of life at sea SOLAS

The International Convention for the Safety of Life at Sea (SOLAS) is an international maritime safety treaty. It ensures that ships flagged by signatory states comply with minimum safety standards in construction, equipment and operation. SOLAS in its successive forms is generally regarded as the most important of all international treaties concerning the safety of merchant vessel.


A person engaged in the salvage of a ship or items lost at sea.

Scheduled Ancient Monument

As defined in the Ancient Monuments and Archaeological Areas Act 1979, that makes provision for the investigation, preservation and recording of matters of archaeological or historical interest

Scottish Environment Protection Agency SEPA

The Scottish Environment Protection Agency is an executive non-departmental public body of the Scottish Government. The SEPA is Scotland's environmental regulator and is responsible for the protection of the natural environment in Scotland. Its main role is to protect and improve Scotland's environment.


Hole in a vessel's side to carry water overboard from the deck.

Ship's plans

Blueprint drawings showing ship construction.

Sites of special scientific interest SSSI

Sites of special scientific interest (SSSI) are important sites designated and protected for being the best examples of their characteristic wildlife and geology. Many of these varied habitats have developed over hundreds of years through management practices such as grazing and forestry and, in most cases, need active management to maintain their conservation status. Also see Areas of nature conservation (ANC) and Areas of Special Scientific Interest (ASSI)

Slave control panel

Control panels of a secondary nature in building systems; they may not have the full functionality found in the master control panel

SMART motorway SMART

A section of motorway that uses active traffic management techniques to increase capacity by use of variable speed limits and hard shoulder running at busy times.

Special Area of Conservation SAC

Strictly protected sites designated under the EC Habitats Directive. Refer to

Special Protection Area SPA

Strictly protected sites classified in accordance with Article 4 of the EC Birds Directive. Refer to


A miniature explosive device used to generate mechanical force, for example ejection of aircraft components

Stability liaison officer

Functional role responsible for co-ordinating the liaison with subject matter experts affecting vessel stability.

Sternal notch

The sternal notch is a well-defined, triangular depression in the lower front of the human throat

Stoichiometric mixture

An "ideal" fuel/air mixture in which both the fuel and the oxygen in the air are completely consumed

Strategic Co-ordinating Group SCG

Multi-agency body responsible for co-ordinating the joint response to an emergency at the local strategic level

Strategic Co-ordination Centre SCC

The location at which the Strategic Co-ordinating Group meets


A thin strip of material to which the skin of the aircraft is fastened

Technical rescue team

Technical rescue teams are those who employ specialist rescue tools and skills. These disciplines include rope rescue, swift-water rescue, confined space rescue, ski rescue, cave rescue, trench/excavation rescue, and building collapse rescue, among others. 

Total Operations Processing System TOPS

A computer management system which tracks the position and status of traction units and rolling stock

Traction current

Term used for electric power supply for electric rail vehicles. Normally supplied by overhead wire or electrified rail and collected by a pantograph on the roof of the train in the former case, or by shoes attached to the bogies in the latter.

Triacetone triperoxide TATP

Home-made explosive. 

Tunnel-boring machine TBM

A machine used to excavate tunnels with a circular cross section through a variety of soil and rock strata. 

Unmetalled road

A road that does not have a hard surface

Upper explosive limit UEL

Maximum concentration of vapour/gas in air at a given pressure and temperature in which a flame can be propagated. 

Upper flammable, limit

Maximum concentration of vapour/gas in air at a given pressure and temperature in which a flame can be propagated. 

Vacuum mattress

A medical device used for the immobilisation of patients, especially in case of a vertebra, pelvis or limb trauma, in particular for femur trauma. It is also used for manual transportation of patients for short distances as an alternative to a stretcher.

Vertical fuel arrangement

A description of the distribution of fuels on the vertical plane, from the ground up to the canopy levels of vegetation. The vertical arrangement of fuels will influence the relative ease with which fire can spread vertically through the fuel layers

Veterinary organisations

This includes: 

  • BARTA – British Animal Rescue & Trauma Care Association 

  • BEVA – British Equine Veterinary Association 

  • BVA – British Veterinary Association 

  • RCVS – Royal College of Veterinary Surgeons 

Wales Resilience Forum

Multi-agency group providing the mechanism for national multi-agency cooperation and strategic advice on civil protection and emergency planning

Waste Industry Safety and Health forum

Representatives from the waste management and recycling industry. Members include the Health and Safety Executive, professional associations, trade unions and government bodies involved in waste management and recycling.

Water bottoming

Technique for managing a leak using water in a container of a substance with lower density than water, to displace the substance above the point of the leak.


Person navigating to a particular location, especially in complex environments


The air resistance of a moving object, such as a vessel or a rotating machine part, or the force of the wind on a stationary object. 

Work positioning

Fall protection system that enables the user to work supported in tension or suspension in such a way that the fall is prevented

Work restraint

Personal fall protection system that restricts the travel of the user away from potentially hazardous areas. 

Workplace exposure limit WEL

Workplace exposure limit - maximum concentration of an airborne substance to which employees may be exposed, averaged over a specific period of time, the two periods used are long term (eight hours) and short term (15 minutes). It is an offence to exceed them (COSHH 2005).


A disease which can be transmitted to humans from animals