Glossary of Terms and Definitions

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

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Glossary of Terms and Definitions