Glossary

3-com: A business whose premises were affected by the Buncefield incident
ACMH: Advisory Committee on Major Hazards
ALARP: acronym for the legal term ‘as low as reasonably practicable’. It requires the weighing up of the level of risk against the costs in the widest sense of averting that risk. Only where the dutyholder can show that the costs of averting the risk are grossly disproportionate to the benefits from further reducing the risk can it be said that the risk has been reduced ALARP.
ambient temperature: The temperature of the surrounding air
API: American Petroleum Institution. It is the American national trade association for the petroleum industry, but it has an increasingly collaborative stance with other bodies such as BSI. API produces a number of guides to standards and recommended practices. Of interest in API Recommended Practice 2350 Overfill protection for storage tanks in petroleum facilities which is currently being reviewed
Aquifer: A water-bearing stratum of porous rock, gravel or sand
ATG: Automatic tank gauging system
BAA: BAA plc operates airports, including London Heathrow
bar and millibar: Although a bar is not a measure in the International System of Units (SI), it is one of the units used in meteorology when describing atmospheric pressure. The SI unit formeasuring pressure is the pascal (Pa). A millibar is equal to 1/1000 of a bar, or 100 pascals (a hectopascal).
Bioaccumalitive: Literally, to accumulate in a biological system. It is commonly taken to measure the uptake over time of toxic substances that can stay in a biological system.
Borehole -: A cylindrical shaft drilled into the ground, often for geological exploration or extraction of resources
Bronze command: The working name for the operational command level during a Major Incident
BSI: Formerly British Standards Institution, now the BSI group, it was founded in 1901 as the Engineering Standards Committee, it is now diversified into making standards, certifying management systems, product testing and other engineering services related to quality
Buncefield Standards Task Group: The joint Competent Authority/industry standards working group set up to review safety and environmental protection standards at fuel storage sites following the Buncefield incident. The Task Group published its initial recommendations on 12 October 2006
Bund -: An enclosure designed to contain fluids should they escape from the tank or vessel inside the bund
Catherine House: A building effected by the Buncefield incident
CENELEC: European Committee for Electrotechnical Standardisation
Civil Contingencies Act (CCA): The Civil Contingencies Act was set up in order to deliver a single framework for civil protection in the United Kingdom. The act is divided into two parts. The first sets out the roles and responsibilities for those involved in emergency preparation and response at a local level, whilst the second updates the 1920 Emergency Powers Act, taking into account the developments over the years, as well as potential risk factors faced in the 21st century.
Civil Contingencies Secretariat (CCS): The Civil Contingencies Secretariat is housed within the Cabinet Office, and works alongside other Government departments, the devolved administrations and key stakeholders to assist with emergency preparation, response and recovery in the UK.
COMAH: The Control of Major Accident Hazards Regulations 1999 Regulations (COMAH).
COMAH sites: sites to which the COMAH Regulations apply.
Competent Authority: The COMAH Regulations are enforced by a joint Competent Authority comprising HSE and EA in England and Wales, and HSE and the Scottish Environment Protection Agency (SEPA) in Scotland. The Competent Authority operates to a Memorandum of Understanding which sets out arrangements for joint working.
Containment: Barriers which, in the event of a spill, can prevent spilled materials from reaching the environment
Contaminants: Substances that have an adverse effect on air, water or soil
Control of Major Accident Hazards Regulations 1999: The main aim of these Regulations is to prevent and mitigate the effects of those major accidents involving dangerous substances, such as chlorine, liquefied petroleum gas, and explosives which can cause serious damage/harm to people and/or the environment. The Regulations treat risks to the environment as seriously as those to people. They apply where threshold quantities of dangerous substances identified in the Regulations are kept or used. See also Seveso II.
controlled burn: A strategy used to reduce the risk of the run-off of contaminated firewater, by limiting or prohibiting the application of fire fighting water or foam.
Dangerous dose: A dose large enough to lead to: severe distress to all; a substantial number requiring medical attention; some requiring hospital treatment; and some (about 1%) fatalities
Dioxin: Toxic chemical by-products of incinerationand some industrial processes that use chlorine.
duty holder: In the context of this report, any person or organisation holding a legal duty – in particular those placed by the HSW Act, the MHSWR, and the COMAH Regulations
Environment Agency: The Environment Agency is the lead regulator in England and Wales with responsibility for protecting and enhancing the environment. It was set up by the Environment Act 1995 and is a non-departmental public body, largely sponsored by the Department for Environment, Food and Rural Affairs and the National Assembly for Wales.
Firefighting pumps: The pumping equipment, normally permanently installed in a pumphouse to move water around the site during fire fighting operations
fire-water: Water stored for use during, and used during, fire-fighting operations
firewater lagoon: an artificial pond that principally stores water intended for firefighting operations
fire waters: A mix of waters, oils and fire-fighting foam
flashpoint: The lowest temperature at which a liquid gives off sufficient vapour to form a flammable mixture
foam/foam concentrate -: In the context of our reports, a concentrate used during operations to extinguish hydrocarbon fires
forthwith action: The Investigation terms of reference require the Investigation team and Board to '... identify and transmit without delay to duty holders and other appropriate recipients any information requiring immediate action to further safety and/or environmental protection in relation to storage and distribution of hydrocarbon fuels.' This is referred to as 'forthwith' action for both the Investigation, the Competent Authority, and duty holders.
Fuji: A business whose premises were effected by the Buncefield incident.
Gold command: The working name for the strategic command centre during a Major Incident - also known as the Strategic Co-ordinating Group
Groundwater: All water below the water-table, as opposed to 'ground waters', which include groundwater but also sub-surface water above the water-table.
hazard: Anything with the potential to cause harm
Health and Safety Commission: The Health and Safety Commission is a statutory body, established under the Health and Safety at Work etc Act 1974, responsible for health and safety regulation in Great Britain.
Health and Safety Executive: The Health and Safety Executive is a statutory body, established under the Health and Safety at Work etc Act 1974. It is an enforcing authority working in support of the HSC. Local authorities are also enforcing authorities under the Health and Safety at Work etc Act 1974.
High reliability organisations: Robust organisations with a strong safety culture that have a high probability of achieving safe and reliable performance.
High integrity systems: Systems that are designed and maintained so that they have a high probability of carrying out their intended function. Safety instrumented systems having safety integrity levels in the range SIL1 to SIL4 are regarded as high integrity systems
HSC: See Health and Safety Commission
HSE: See Health and Safety Executive
Human factors: HSE has defined human factors (also known as Ergonomics) as the environmental, organisational and job factors, and human and individual characteristics which influence behaviour at work.
Hydraulic pressure: Pressure exerted by water
hydrocarbon: An organic chemical compound of hydrogen and carbon. There are a wide variety of hydrocarbons such as crude oil (basically a complex mixture of hydrocarbons), methane, propane, butane, etc. They are often used as fuels
IEC: International Electrotechnical Commission
Improvement Notice: Improvement notices are one of a range of means which enforcing authorities use to achieve the broad aim of dealing with serious risks, securing compliance with health and safety law and preventing harm. An Improvement Notice Improvement Notice allows time for the recipient to comply.
Independent overfill protection system: A system that detects when the liquid in a storage tank has reached a level where continued further filling will result in loss of containment and acts to prevent further filling in time to prevent such loss of containment. Where such systems are automatic they do not rely on any human operator action
Inversion layer: This is the boundary between layers of air of distinctly different temperature, often quite sharply defined, as at Buncefield. In a temperature invesion, the normal vertical temperature gradient is inverted such that the air is colder near the surface of the Earth. This can occur when radiation from the surface of the earth is less than the amount of radiation received from the sun, which commonly occurs at night, or during the winter when the angle of the sun is very low in the sky
kilopascal: Pascals (Pa) are the unit of pressure in the International System of Units (SI). A kiloPascal (kPa) is equal to 1000 Pa. Although bar are not units within SI, they are sometimes used as units to measure atmospheric pressure. 1kPa = 10 bar. See also bar and millibar
kPa: See kiloPascal
Local Resilience forum: The Local Resilience Forum (LRF) is the principal mechanism for multi-agency co-operation between Category 1 responders. The LRF is not a statutory body, but it is a statutory process under the Civil Contingencies Act 2004.
lower-tier: See tier
Major Accident To The Environment: DEFRA has established threshold criteria defining a 'Major Accident To The Environment' (MATTE), based on Schedule 7 (part 1) of the Control of Major Accident Hazards Regulations 1999. The Environment Agency, using these criteria, has determined that the Buncefield incident is a MATTE, and the Competent Authority has recently reported this to the European Commission.
Manual emergency switches: Simple and robust push switches that will initiate emergency action such as shutting down pumps or interrupting process operations, and which are located at strategic and accessible locations around the site
MATTE: See Major Accident To The Environment
millibar: See bar
Northgate: A business whose premises were effected by the Buncefield incident
on- and off-site emergency: plans Operators of top-tier COMAH sites must prepare adequate emergency plans to deal with the on-site consequences of possible major accidents and to assist with off-site mitigation. Local authorities for areas containing top-tier COMAH sites must prepare adequate emergency plans to deal with the off-site consequences of possible major accidents, based on information supplied by site operators
outfall: The point of discharge of water into a river, stream, pond, sea or other water body
Overpressure: For a pressure pulse (or blast wave), the pressure developed above atmospheric pressure is called the overpressure
Particulates: fine particles (liquid or solid) suspended in the air such as dust, smoke, fumes, and so on
Pasquill stability category: A category within a classification scheme used to describe the degree of atmospheric turbulence
perflourooctane sulphonate: A group of chemicals, collectively identified as PFOS, which have been shown to be hazardous (persistent, bioaccumulative and toxic). PFOS chemicals have been used in a diverse range of applications, including as an additive to aid the spreading properties of fire-fighting foam.
Perfluorosurfactant: a type of surfactant
PFOS: Perfluorooctane sulphonate
Planning Advice for Developments near Hazardous Installations (PADHI): software tool developed by HSE which in the vast majority of cases allows local planning authorities to obtain HSE’s advice on an intended development within the consultation distance of a major hazard site.
Polycyclic aromatic hydrocarbons and compounds: a group of chemicals commonly found in residues from burning coal, fuel and oil
Pollution dispersion model: A model used to describe the transport and diffusion of pollutants in the atmosphere
pool fire: A fire over a pool of fuel and/or water or other liquids
primary containment: The tanks, pipes and vessels that normally hold liquids, and the devices fitted to them to allow them to be safely operated.
Prohibition Notice: Issuing improvement or prohibition notices are some of the range of means which enforcing authorities use to achieve the broad aim of dealing with serious risks, securing compliance with health and safety law and preventing harm. A prohibition notice stops work in order to prevent serious personal injury
public information zone (PIZ) -: An area around a COMAH site, in which site operators are obliged to inform, without request, those who live and/or work within the zone with information on safety measures at the establishment and on the requisite behaviour in the event of a major accident at the establishment. This is in accordance with regulation 14 of COMAH.
Pumphouse: In the context of this report, the structure enclosing the pumping equipment used to move water around the Buncefield site prior to the incident - principally stored water intended for fire-fighting operations.
Pyrolysis: The decomposition or transformation of a compound caused by heat
Quantified risk analysis/assessment (QRA): a systematic analytical technique for quantifying the risks associated with hazardous installations, based on assessing a range of foreseeable failure scenarios. The risk to an individual at a specific location is the summation of the risks arising from the different scenarios.
reasonable praticability: risks are deemed as low as reasonably practicable (ALARP) where there is gross disproportion between the costs to the dutyholder of doing more, against the benefit gained (in terms of risk reduction) in doing it.
Regional Resilience Forum: The Regional Resilience Forums are established by each Government Office to discuss civil protection issues from the regional perspective and to create a stronger link between local and central government on resilience issues. Similar arrangements are made in the devolved administrations.
Regional Resilience Team: The Regional Resilience Team is a small group of civil servants within a regional government office dealing with civil protection issues under the leadership of a regional resilience director. Similar arrangements will exist in the devolved administrations.
responder: Under the Civil Contingencies Act 2004, EA is a Category 1 responder, and HSE is a Category 2 responder. These categories define the roles played by each body in response to a major incident
Risk: The likelihood that a hazard will cause a specified harm to someone or something
RO: A business whose premises were effected by the Buncefield incident
run off: Uncontained liquid, either deposited on-site as rain, or in the context of the Buncefield incident, fuel and/or fire-water not contained as part of the operation to control the incident.
Safety alert: Where the Competent Authority considers that an issue poses significant risk, it can choose to issue a Safety Alert to operators of COMAH sites informing them of the issue and possibly requiring them to undertake certain activity
Safety integrity level (SIL): A safety integrity level (SIL) is a measure of safety system performance, in terms of the probability of failure on demand. There are four discreet integrity levels, SIL 1-4. The higher the SIL level, the higher the associated safety level and the lower the probability that a system will fail to perform properly.
safety reports: The COMAH Regulations require operators of top-tier sites to submit written safety reports to the Competent Authority
SCADA system: High-level supervisory control and data acquisition system
SCG: See Strategic Co-ordinating Group
Scottish Environment Protection Agency: public body which is responsible for the protection of the environment in Scotland.
secondary containment: Enclosed areas around storage vessels (often called bunds), created usually by concrete or earth walls. Their purpose is to hold any escaping liquids and any water or chemicals used in fire-fighting.
SEPA: See Scottish Environment Protection Agency
Servo level gauge: measures the liquid level in tanks
Seveso II: In 1976, a major accident occurred in Seveso, Italy, where the accidental production and release of a dioxin as an unwanted by-product from a runaway chemical reaction led to widespread contamination. A number of such incidents, and the recognition of the differing standards of controls over industrial activities within the European Community, led the European Commission to propose a Directive on the control of major industrial accident hazards. The Directive on the Major Accident Hazards of Certain Industrial Activities (82/501/EEC) was adopted on 24 June 1982, and is generally known as the Seveso Directive. Following a complete review of the Directive by the European Commission a new one, now known as Seveso II, came into force on 3 February 1997 and was implemented in Great Britain on 1 April 1999 by the Control of Major Accident Hazards Regulations 1999, except for land use planning requirements, which were implemented by changes to planning legislation.
Silver command -: The working name for the tactical command centre during a Major Incident
Strategic Co-ordinating Group: Representation of all agencies deployed to resolve the Buncefield incident was established through a meeting process known as the Strategic Co-ordinating Group, also known as Gold Command.
surface water: Water that sits or flows above land, including lakes, seas, rivers and streams.
Surfactant: A chemical added to fire-fighting foam which allows the foam to form a thin sealing film over the burning fuel
tank farm: A facility where hazardous substance, very often petroleum products, are stored in tanks.
tertiary containment: The site surface and associated drainage, boundary walls, roads, containment kerbs and any features such as road humps that can provide some retention of liquids. Proper design of drainage systems will limit loss of product out of the site and prevent lost product permeating into the ground with the potential risk that it can migrate to groundwater, or contaminate surface waters and land.
tier: The COMAH Regulations apply where threshold quantities of dangerous substances identified in the Regulations are kept or used. There are two thresholds, known as ‘lower-tier’ and ‘top tier’. Annex 1 gives a brief background to the origins of these Regulations
topography: The physical configuration of the surface of the land, including its elevation, slope, and orientation.
top-tier: See tier
ullage: The volume in the tanks between the normal maximum operating volume and when the tank is completely full of liquid
ultimate high-level switch: Part of the system to prevent overfilling of the tank, the ultimate high-level switch is an independent mechanism which should be triggered when the ‘ultimate high level’ (ie the specified maximum capacity) is reached in a tank to which it is fitted, causing an alarm to sound and should shut down the supply of fuel to the tank.
Vapour pressure: a measure of the tendency of a material to form a vapour. The higher the vapour pressure, the higher the potential vapour concentration.
volatile: A substance which evaporates readily, even below its boiling temperature
volatility -: The readiness of a substance to evaporate
watercourses: A natural or man-made channel along which water flows
wind girder: Structural stiffening ring attached to the tank side wall.

Buncefield Investigation

Glossary