afterflame
flame which persists after the ignition source has been removed

afterflame time
length of time for which an afterflame persists under specified conditions

afterglow
persistence of glowing combustion after both removal of the ignition source and the cessation of any flaming

afterglow time
length of time for which an afterglow persists under specified conditions

air inlet
device connected to outside air to allow the inlet of air from outside the construction work

area burning rate
area burned per unit time under specified conditions

ash
ashes mineral residue resulting from complete combustion

assembly
unit or structure composed of a combination of materials or products, or both

BS EN 12101-1 2005
Smoke and heat control systems. Specifications for smoke curtains

BS 7346 Part 3 1990
Smoke and heat control systems. Specifications for smoke curtains

BS 476 Part 6 1989
Fire tests on building materials and structures. Methods of test for fire propagation for products

BS 476 Part 7 1997
Fire tests on building materials and structures. Methods of test to determine the classification of the surface spread of flame of products

BS 476 Part 22 1987
Determination of the fire resistance of uninsulated doorsets and shutter assemblies

BS EN1634-1:2000
Fire resistance tests for door and shutter assemblies. Fire doors and shutters

BS EN1363-1:1999
Fire resistance tests. General requirements

BS EN1363-2:1999
Fire resistance tests. Alternative and additional procedures

BS EN1364-1:1999
Fire resistance tests for non-load bearing elements for Walls

BS EN1364-2:1999
Fire resistance tests for non-load bearing elements for Ceilings

BS476-20:1987
Fire tests on building materials and structures. Methods for determination of the fire resistance of elements of construction (general principles)

burn
intransitive verb to undergo combustion

burned area
that part of the damaged area of a material that has been destroyed by combustion or pyrolysis under specified conditions cf. damaged area

burned length
maximum extent in a specified direction of the burned area cf. damaged length

burning behaviour
all the physical and/or chemical changes that take place when an item is exposed to a specified ignition source

calorific value
cf. heat of combustion.

char, noun.
carbonaceous residue resulting from pyrolysis or incomplete combustion

char, verb.
to form carbonaceous residue during pyrolysis or combustion

char length
length of carbonaceous residue cf. burned length

chimney effect
upward movement of hot fire effluent caused by convection currents confined within an essentially vertical enclosure

clinker
solid agglomerate of residues formed by either complete or incomplete combustion and which may result from complete or partial melting

combustible, adj.
capable of being combusted

combustible, noun.
item capable of combustion

combustion
exothermic reaction of a substance with an oxidizer

commissioning
the act of ensuring that all components and the system are installed and operating in accordance with this standard

composite material
structured combination of two or more discrete materials

damaged area
total of those surface areas which have been affected permanently by fire under specified conditions cf. burned area

damaged length
maximum extent in a specified direction of the damaged area cf. burnt length

draught-free environment
environment in which the results of experiments are not significantly affected by the local air speed

duration of flaming
length of time for which flaming combustion persists under specified conditions, including flaming combustion due to the presence of an ignition source

ease of ignition
Deprecated term cf. ignitability and minimum ignition time.

elevated temperature
temperatures in excess of normal ambient air, below those necessary for fire resistance testing, to which smoke and heat exhaust ducts for single compartments are tested

end-use conditions
intended conditions to which an item will be subjected during its normal working life, when used in accordance with the manufacturer's instructions

environment
conditions and surroundings that may influence the behaviour of an item or persons when exposed to fire

explosion
abrupt expansion of gas which may result from a rapid oxidation or decomposition reaction, with or without an increase in temperature

exposure time
length of time for which people, animals or items are exposed under specified conditions

fire (controlled)
self-supporting combustion which has been deliberately arranged to provide useful effects and which is controlled in its extent in time and space

fire (uncontrolled)
self-supporting combustion which spreads uncontrolled in time and space

fire barrier
separating element which resists the passage of flame and/or heat and/or effluents for a period of time under specified conditions

fire behaviour
change in the physical and/or chemical properties of an item and/or structure exposed to fire

fire compartment
an enclosed space, comprising one or more separate spaces, bounded by elements of construction having a specified fire resistance and intended to prevent the spread of fire (in either direction) for a given period of time NOTE Fire compartment often has regulatory connotations. The term should not be confused with "room of origin" or "fire cell".

fire effluent
totality of gases and/or aerosols (including suspended particles) created by combustion or pyrolysis

fire exposure
extent to which persons, animals or items are subjected to the conditions created by fire

fire gases
gaseous part of the products of combustion cf. fire effluent

fire hazard
potential for injury and/or damage from fire

fire Ioad
quantity of heat which could be released by the complete combustion of all the combustible materials in a volume, including the facings of all bounding surfaces

fire load density
fire load per unit floor area NOTE It is expressed in joules per square metre

fire model
procedure or process intended to represent, predict or reproduce one or more phases of a fire or the transition between phases

fire performance
response of an item when exposed to a specific fire cf. fire behaviour

fire point
minimum temperature at which a material ignites and continues to burn for a specified time after a standardized small flame has been applied to its surface under specified conditions cf. flash point

fire resistance
ability of an item to fulfil for a stated period of time the required stability and/or integrity and/or thermal insulation, and/or other expected duty specified in a standard fire-resistance test

fire retardance
Deprecated term.

fire retardant, noun
substance added, or a treatment applied, to a material in order to delay ignition or to reduce the rate of combustion

fire risk
product of — probability of occurrence of a fire to be expected in a given technical operation or state, and — consequence or extent of damage to be expected on the occurrence of a fire

fire scenario
detailed description of conditions, including environmental, of one or more stages from before ignition to after completion of combustion in an actual fire at a specific location or in a real-scale simulation

fire simulation
cf. fire model

flame, noun
zone of combustion in the gaseous phase, usually with emission of light

flame, verb
to undergo combustion in the gaseous phase with emission of light

flame front
boundary of flaming combustion at the surface of a material or propagating through a gaseous mixture

flame resistance
Deprecated term

flame retardance
property of a material whereby flaming combustion is slowed, terminated or prevented

flame retardant, noun
substance added, or a treatment applied, to a material in order to suppress or delay the appearance of a flame and/or reduce its propagation (spread) rate cf. fire retardant

flame-retardant treatment
process whereby improved flame retardance is imparted to a material or product

flame retarded
treated with a flame retardant

flame spread
propagation of a fire front

flame spread rate
distance travelled by a fire front during its propagation, divided by the time of travel, under specified conditions

flame spread time
time taken by a fire front on a burning material to travel a specified distance on the surface, or to cover a specified surface area under specified conditions

flameproof
Deprecated term, except in the context of electrical equipment for explosive atmospheres

flaming combustion
combustion in gaseous phase, usually with emission of light

flaming debris
flaming droplets material separating from a burning item during the fire test procedure and continuing to flame

flammability
ability of a material or product to burn with a flame under specified conditions

flammable
capable of flaming under specified conditions

flash point
minimum temperature to which a material or a product must be heated for the vapours emitted to ignite momentarily in the presence of flame under specified conditions

flash-over
transition to a state of total surface involvement in a fire of combustible materials within an enclosure

flashing
existence of flame repeated for very short periods of time (e.g. between 0 s and 1 s) on or over the surface of the specimen

full fire development
evolution of a fire to a state of full flaming of combustible materials

fully developed fire
state of total involvement of combustible materials in a fire

glowing
made luminous by heat cf. incandescence

heat flux
amount of thermal energy emitted, transmitted or received per unit area and unit time

heat of combustion
thermal energy produced by combustion of unit mass of a given substance

(effective) heat of combustion
heat of combustion of a substance under specified conditions gross heat of combustion heat of combustion of a substance when the combustion is complete and any produced water is entirely condensed under specified conditions

(net) heat of combustion
heat of combustion of a substance when the combustion is complete and any produced water is in the vapour state under specified conditions

heat release
thermal energy which is released by the combustion of an item under specified conditions

heat release rate
thermal energy released per unit time by an item during combustion under specified conditions

heat stress
conditions caused by exposure to elevated/reduced temperature, radiant heat flux (85), or a combination of these factors

"I" criterion
cf. thermal insulation criterion "I"

ignitability
measure of the ease with which an item can be ignited under specified conditions

ignitable
capable of being ignited

ignite
intransitive verb to catch fire with or without the application of an external heat source

ignite
transitive verb to initiate combustion cf. light

ignited, adj
state of an item undergoing combustion

ignition
initiation of combustion

ignition source
source of energy that initiates combustion

ignition temperature
(minimum) temperature at which combustion can be initiated under specified test conditions

ignition time
Deprecated term. cf. minimumignition time

ISO 9001 2000
Quality systems model for quality assurance in design, development, production, installation and servicing

incandescence
emission of light produced by a material when intensely heated cf. glowing

inflammability
Deprecated term cf. flammability

inflammable
Deprecated term. cf. flammable

integrity
ability of a separating element when exposed to fire on one side, to prevent the passage of flames (60) and hot gases or the occurrence of flames on the unexposed side, for a stated period of time in a standard fire resistance test

integrity criterion "E"
criterion by which the ability of a separating element to prevent the passage of flames and hot gases is assessed cf. fire resistance

intermediate-scale test
test performed on an item of medium dimensions

large-scale test
test, which cannot be carried out in a typical laboratory chamber, performed on an item of large dimensions

linear burning rate
length of material burned per unit time under specified conditions specified actions during the relevant fire resistance test is assessed cf. fire resistance

mass burning rate
mass of material burned per unit time under specified conditions

mass loss rate
mass of material lost per unit time under specified conditions

minimum ignition time
duration of exposure of a material to a defined ignition source required for the initiation of combustion under specified conditions. cf. ease of ignition and exposure time

multi compartment fire resisting smoke control system ducts
fire resisting ducts for use in multi compartment application and that have been tested and met the requirements of prEN 1366-8

natural smoke and heat control system
a smoke and heat ventilation system which uses natural ventilation. Natural ventilation is caused by buoyancy forces due to differences in density of the gases because of temperature differences

numerical fire model
mathematical representation of one or more of different interconnected phenomena governing the development of a fire

non-combustible
not capable of undergoing combustion under specified conditions

non-flammable
not capable of burning with a flame under specified conditions

opacity of smoke
measure of the attenuation of a light beam passing through smoke expressed as the ratio of incident luminous flux to transmitted luminous flux through smoke under specified conditions

optical density of smoke
measure of the attenuation of a light beam passing through smoke expressed as the common logarithm (i.e. logarithm to the base Ig of the opacity of smoke)

oxygen index
OI minimum concentration of oxygen in a mixture of oxygen and nitrogen that will just support flaming combustion of a material under specified conditions

PAS 121:2007
Publicly Available Specification for active fire curtain barrier assembly’s and active fire curtain barrier assembly’s with smoke rating

penetration seal
the product used between the smoke control system duct and the fire compartment structure to maintain the fire resistance, when tested and having met the requirements of prEN 1366-8, at the position where a smoke control system duct passes through the element

physical fire model
laboratory process, including the apparatus, the environment and the test procedure intended to represent a certain phase of a fire

pilot[ed] ignition
ignition of combustible gases or vapours by a secondary source of energy, as by, for example, a flame, spark, electrical arc or glowing wire

powered smoke and heat exhaust system
a smoke and heat ventilation system which utilises a number of hot gas fans that are suitable for handling hot gases for a limited period of time which causes the positive displacement of gases

pressure differential systems
a system of fans, ducts, vents and other features provided for the purposes of creating a lower pressure in the fire zone than in the protected space - see prEN 12101-6

products of combustion
solid, liquid and gaseous materials resulting from combustion cf. fire effluent

pyrolysis
that part of the irreversible chemical decomposition caused solely by a rise in temperature

pyrophoric material
material capable of igniting spontaneously when brought into contact with air

"R" criterion
cf. load-bearing criterion "R"

rate of burning
burning rate Deprecated terms. cf. area burning rate , linear burning rate , mass burning rate , flame spread rate, heat-release rate , as appropriate

rate of heat release
cf. heat release rate

reaction to fire
response of a material in contributing by its own decomposition to a fire to which it is exposed, under specified conditions

real-scale test
test which simulates a given application, taking into account the real scale, the real way of working or installation and the environment

scorch, verb
to modify the surface of material by limited carbonization due to heat

screening test
preliminary test used for ascertaining whether an item is likely to exhibit (or not) certain characteristics according to a standardized test method

self-extinguishing
deprecated term

self-propagation of flame
propagation of a fire front after the removal of any applied energy source

self-extinguishibility
deprecated term

self-heating
rise in temperature in a material resulting from an exothermic reaction within the material, Electrotechnical, heat generated by a powered electrotechnical product resulting in a rise in temperature in the product

self-ignition
spontaneous ignition resulting from self-heating

self-ignition temperature
Deprecated term. cf. spontaneous ignition temperature

single compartment smoke control system ducts
ducts for use within single fire compartment application and that have been tested and met the requirements of prEN 1366-9

small-scale test
test performed on an item of small dimensions

smoke
visible part of fire effluent

smoke and heat exhaust ventilation system (SHEVS)
system consisting of components jointly selected to exhaust smoke and heat. The components form a system which complies with the requirements of prEN 12101-4 in order to establish a buoyant layer of warm gases above cooler cleaner air

smoke and heat exhaust ventilator (SHEV)
device specially designed to move smoke and hot gases out of a construction work under conditions of fire

smoke barrier
a barrier to restrict the spread of smoke and hot gases from a fire, forming part of the boundary of a smoke reservoir or used as a channelling screen, or used as a void edge boundary

smoke control system damper
a device automatically or manually activated, which may be open or closed in its operational position, to control the flow of smoke and hot gases into, from or within a duct

smoke control system duct
a duct used in a system to control the movement and/or containment of smoke and heat

smoke layer
layer of smoke that stabilizes underneath the roof due to the affect of temperature gradient

smoke logging
a condition within a building when the hot gases from a fire descend within it to a level whereby the safe escape of the occupants is hampered and the ingress of firefighters is prevented

smoke obscuration
reduction in the intensity of light due to its passage through smoke

smouldering
combustion of a material without flame and without light being visible cf. glowing combustion

smoke reservoir
region within a building limited or bordered by smoke barriers or structural elements and which will, in the event of a fire, retain a thermally buoyant smoke layer

smoke zone (zones)
areas into which a construction works is divided for the extraction of smoke and hot gases. Each zone is served by a SHEV, (or sub-system of a SHEV), which is initiated by a signal from a single or group of initiation devices associated with the zone

soot
particulate matter produced and deposited during or after combustion

specific optical density of smoke
measure of the opacity of the smoke produced by a specimen taking into account the optical density and factors characteristic of the specified test method cf. optical density of smoke

spontaneous combustion
Deprecated term. cf. self-ignition

spontaneous ignition
ignition resulting from a rise of temperature without a separate ignition source

spontaneous ignition temperature
minimum temperature at which ignition is obtained under specified test conditions without any source of pilot ignition
surface burn
combustion limited to the surface of a material cf. surface flash

surface flash
movement of transient flame over the surface of a material without ignition of its basic structure. cf. surface burn

surface spread of flame
propagation of flame away from the source of ignition across the surface of a liquid or a solid

sustained flaming
persistence of flame on or over a surface for a minimum period of time

temperature-time curve
(standardized) time-related variation of temperature prescribed in a specified way during a standard fire resistance test

thermal decomposition
process whereby the action of heat or elevated temperature on an item causes changes to the chemical composition

thermal degradation
process whereby the action of heat or elevated temperature on an item causes a loss of some properties (e.g. physical, mechanical or electrical)

thermal insulation criterion
criterion, determined from the results of a fire resistance test, by which the ability of a separating element to prevent the passage of heat is assessed cf. fire resistance

thermal radiation
transfer of thermal energy by electromagnetic waves

tL50
lethal exposure time duration of exposure to a fixed concentration of toxic gas or fire effluent, that causes death to 50% of a population of a given species

toxic hazard
potential for injury or loss of life by exposure to toxicants with respect to their potency, quantity, concentration and duration of exposure cf. fire hazard, fire risk and toxic risk

toxic potency
measure of the amount of toxicant required to elicit a specific toxic effect

toxic risk
result of the mutiplication of — the probability of occurrence of a toxic hazard to be expected in a given technical operation or state, and — the consequence or extent of injury to be expected on the occurrence of a toxic hazard

toxicant
substance which causes an adverse effect upon a living organism

toxicity
ability of a substance to produce adverse effects upon a living organism

tracking resistance
ability of a material to withstand a test voltage, under specified conditions, without creating conducting paths on the surface of the specimen and without the occurrence of flame cf. electrical tracking resistance

transitory flaming
existence of flame on or over the surface of the specimen for a period of time longer than that of surface flash but shorter than that of sustained flaming

transmittance
through smoke ratio of transmitted luminous flux through smoke to incident luminous flux under specified conditions

ultimate stability failure
change in the test element which is of sufficient magnitude to result in its rupture or collapse after a very short period of time in a standard fire resistance test

wicking
transmission of a fluid through or over a particle or fibrous material by capillary action