Smoke explosion - Revision history

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2026-11-02T17:12:23Z

Add Intermediate SVG figures with Fire Safety Academy watermark at planned locations; preserve article text

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	The second kind is a smouldering fire. Smouldering is a slow combustion process with low gas temperatures and no flames, and it can generate high levels of carbon monoxide.<ref name="GL-54" /> Without flames, the unburned fuel and carbon monoxide from a smouldering fire can build up to form a premixed combustible atmosphere.<ref name="IS-15-4" /> This is the route described for smoke explosions in polyurethane foam fires.<ref name="IS-15-4" />		The second kind is a smouldering fire. Smouldering is a slow combustion process with low gas temperatures and no flames, and it can generate high levels of carbon monoxide.<ref name="GL-54" /> Without flames, the unburned fuel and carbon monoxide from a smouldering fire can build up to form a premixed combustible atmosphere.<ref name="IS-15-4" /> This is the route described for smoke explosions in polyurethane foam fires.<ref name="IS-15-4" />

			[[File:fse-smoke-explosion-v1.svg\|thumb\|upright=1.5\|alt=Three stages of one room: smouldering sofa filling the room with smoke, a spark igniting the mixed cloud, and the explosion breaking the window.\|A smoke explosion in three stages: unburned gases from a smouldering fire mix with the room air, the premixed cloud is ignited, and the deflagration raises the pressure. Based on Iqbal and Salley (2004), pp. 15-3–15-4, and Van Rossum (2027), §4.10.]]

	The flammable gases in such smoke are products of [[incomplete combustion]]. In a handbook example of a hot smoke layer, they were unburned hydrocarbons, carbon monoxide and hydrogen.<ref name="B-184">Beyler (2002b), p. 2-184.</ref> A Dutch study lists methane, carbon monoxide, carbon dioxide and hydrogen among the usual combustion products released when the battery of an electric vehicle burns.<ref name="VdG-26">Van der Graaf et al. (2021/2023), p. 26.</ref> Before such a cloud can explode, it must be diluted with enough air to fall within its flammable range, but not so much that it falls below it.<ref name="IS-15-4" />		The flammable gases in such smoke are products of [[incomplete combustion]]. In a handbook example of a hot smoke layer, they were unburned hydrocarbons, carbon monoxide and hydrogen.<ref name="B-184">Beyler (2002b), p. 2-184.</ref> A Dutch study lists methane, carbon monoxide, carbon dioxide and hydrogen among the usual combustion products released when the battery of an electric vehicle burns.<ref name="VdG-26">Van der Graaf et al. (2021/2023), p. 26.</ref> Before such a cloud can explode, it must be diluted with enough air to fall within its flammable range, but not so much that it falls below it.<ref name="IS-15-4" />
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	Limits of some gases found in smoke are listed in the SFPE Handbook. Carbon monoxide burns in air between 12.5 and 74 per cent, hydrogen between 4.0 and 75 per cent, and hydrogen cyanide between 5.6 and 40 per cent.<ref name="B-175">Beyler (2002b), pp. 2-175–2-176.</ref> The autoignition temperatures in the same table are 400 °C for hydrogen and 540 °C for methane.<ref name="B-175" /> The limits widen as the temperature of the mixture rises.<ref name="B-174">Beyler (2002b), p. 2-174.</ref> More oxygen raises the upper limit, while the lower limit hardly changes, because a lean mixture already has more oxygen than it needs.<ref name="B-174" />		Limits of some gases found in smoke are listed in the SFPE Handbook. Carbon monoxide burns in air between 12.5 and 74 per cent, hydrogen between 4.0 and 75 per cent, and hydrogen cyanide between 5.6 and 40 per cent.<ref name="B-175">Beyler (2002b), pp. 2-175–2-176.</ref> The autoignition temperatures in the same table are 400 °C for hydrogen and 540 °C for methane.<ref name="B-175" /> The limits widen as the temperature of the mixture rises.<ref name="B-174">Beyler (2002b), p. 2-174.</ref> More oxygen raises the upper limit, while the lower limit hardly changes, because a lean mixture already has more oxygen than it needs.<ref name="B-174" />

			[[File:fse-smoke-explosion-v2.svg\|thumb\|upright=1.5\|alt=Horizontal bars of the flammable ranges in air of methane, carbon monoxide, hydrogen and hydrogen cyanide, with the lower limit of a mixture.\|Flammable ranges in air of four gases found in fire smoke at normal temperature and pressure, and the lower limit of a mixture of methane, carbon monoxide and hydrogen. Based on Beyler (2002b), pp. 2-174–2-176.]]

	Fire gases are mixtures of several fuels. The lower flammability limit of such a mixture can be estimated with an empirical rule of Le Chatelier.<ref name="B-174" /> Each fuel gas contributes to the flammability in proportion to its share of the fuel mixture, divided by its own lower limit:		Fire gases are mixtures of several fuels. The lower flammability limit of such a mixture can be estimated with an empirical rule of Le Chatelier.<ref name="B-174" /> Each fuel gas contributes to the flammability in proportion to its share of the fuel mixture, divided by its own lower limit:
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	Buildings fail long before such pressures are reached. Typical failure pressures are 2 to 7 kPa for glass windows, 2 to 3 kPa for room doors and 2 to 5 kPa for light partition walls.<ref name="IS-15-13">Iqbal and Salley (2004), p. 15-13.</ref> Unrestrained brick walls fail at about 7 to 15 kPa.<ref name="IS-15-13" /> A pressure of 8 bar equals 800 kPa, more than a hundred times the failure pressure of a window. Even a partial explosion of a smoke cloud can therefore break windows, doors and partitions.		Buildings fail long before such pressures are reached. Typical failure pressures are 2 to 7 kPa for glass windows, 2 to 3 kPa for room doors and 2 to 5 kPa for light partition walls.<ref name="IS-15-13">Iqbal and Salley (2004), p. 15-13.</ref> Unrestrained brick walls fail at about 7 to 15 kPa.<ref name="IS-15-13" /> A pressure of 8 bar equals 800 kPa, more than a hundred times the failure pressure of a window. Even a partial explosion of a smoke cloud can therefore break windows, doors and partitions.

			[[File:fse-smoke-explosion-v3.svg\|thumb\|upright=1.5\|alt=Logarithmic pressure scale from 1 to 1000 kPa with failure ranges of windows, doors and walls, injury levels and the 800 kPa explosion maximum.\|Failure pressures of building elements and pressure effects on people compared with the maximum pressure of a premixed gas explosion inside a building. Based on Iqbal and Salley (2004), pp. 15-12–15-13.]]

	The effects on people depend on the pressure and on what is thrown about. The limit for eardrum rupture is about 35 kPa and for lung damage about 70 kPa, while 1 per cent mortality is expected at about 180 kPa.<ref name="IS-15-12" /> When people are killed by blast waves, it is usually by falling objects rather than by the pressure itself.<ref name="IS-15-12" /> After ignition, the flame front travels through the whole mixture.<ref name="IS-15-6">Iqbal and Salley (2004), p. 15-6.</ref> The hazards of a deflagration include the ejection of flame and unburned product into the surroundings, possible secondary explosions and personal injury.<ref name="IS-15-3" />		The effects on people depend on the pressure and on what is thrown about. The limit for eardrum rupture is about 35 kPa and for lung damage about 70 kPa, while 1 per cent mortality is expected at about 180 kPa.<ref name="IS-15-12" /> When people are killed by blast waves, it is usually by falling objects rather than by the pressure itself.<ref name="IS-15-12" /> After ignition, the flame front travels through the whole mixture.<ref name="IS-15-6">Iqbal and Salley (2004), p. 15-6.</ref> The hazards of a deflagration include the ejection of flame and unburned product into the surroundings, possible secondary explosions and personal injury.<ref name="IS-15-3" />
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	In a smoke explosion, the fuel and air are already mixed before any ignition source acts.<ref name="VR-4.10" /> No sudden opening is needed, and the cloud can be ignited by its own temperature or by a spark.<ref name="IS-15-4" /> Rollover, by contrast, is the burning of fuel-rich gases at the boundary between the smoke layer and the air below it. It occurs during underventilated burning and does not involve a premixed cloud.<ref name="GL-55" />		In a smoke explosion, the fuel and air are already mixed before any ignition source acts.<ref name="VR-4.10" /> No sudden opening is needed, and the cloud can be ignited by its own temperature or by a spark.<ref name="IS-15-4" /> Rollover, by contrast, is the burning of fuel-rich gases at the boundary between the smoke layer and the air below it. It occurs during underventilated burning and does not involve a premixed cloud.<ref name="GL-55" />

			[[File:fse-smoke-explosion-v4.svg\|thumb\|upright=1.5\|alt=Three rows of steps comparing smoke explosion, backdraft and rollover by when fuel gases, air and ignition come together.\|Smoke explosion, backdraft and rollover compared by the order in which fuel gases, air and ignition come together. Based on Iqbal and Salley (2004), p. 15-4; Van Rossum (2027), §4.9 and §4.10; Gottuk and Lattimer (2002), p. 2-55.]]

	The NRC guide groups gas explosions and backdraft explosions with dust explosions as combustion explosions.<ref name="IS-15-2">Iqbal and Salley (2004), p. 15-2.</ref> All of them involve a rapid release of high-pressure gas that forms a pressure wave.<ref name="IS-15-2" /> Physical explosions, such as the failure of a tank heated from outside, form a separate group in which the high-pressure gas is produced without a chemical reaction.<ref name="IS-15-2" />		The NRC guide groups gas explosions and backdraft explosions with dust explosions as combustion explosions.<ref name="IS-15-2">Iqbal and Salley (2004), p. 15-2.</ref> All of them involve a rapid release of high-pressure gas that forms a pressure wave.<ref name="IS-15-2" /> Physical explosions, such as the failure of a tank heated from outside, form a separate group in which the high-pressure gas is produced without a chemical reaction.<ref name="IS-15-2" />

Daan: New FSE wiki article: Smoke explosion (written by Claude Opus 5.5)

2026-11-01T22:37:41Z

New FSE wiki article: Smoke explosion (written by Claude Opus 5.5)

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A '''smoke explosion''' is the very rapid burning of a cloud of smoke and air in which flammable gases from a fire are already mixed with oxygen before they are ignited. The flammable gases come from the decomposition of fuels or from incomplete combustion.<ref name="VR-4.10">Van Rossum (2027), §4.10.</ref> A typical condition is that the gases and the surrounding air are reasonably well premixed and that the mixture lies between its lower and upper explosion limits. It can then be ignited by autoignition, when the gas reaches its autoignition temperature, or by a spark or a glowing particle from the fire.<ref name="VR-4.10" />

The event is also called a smoke gas explosion or fire gas explosion.<ref name="IS-15-12">Iqbal and Salley (2004), p. 15-12.</ref><ref name="VdG-27">Van der Graaf et al. (2021/2023), p. 27.</ref> A guide of the US Nuclear Regulatory Commission describes how a smouldering fire can produce enough unburned fuel and carbon monoxide to form a premixed combustible atmosphere. If the fire then heats the mixture to its autoignition temperature, the cloud deflagrates.<ref name="IS-15-4">Iqbal and Salley (2004), p. 15-4.</ref> Such explosions have been observed in smouldering fires of polyurethane foam.<ref name="IS-15-4" /> Unlike most fires, a smoke explosion can produce pressures high enough to damage a building.<ref name="IS-15-12" /> It differs from a [[backdraft]], which is triggered by a sudden supply of air, and from [[rollover]], in which the smoke layer burns at its boundary with fresh air.<ref name="VR-4.9">Van Rossum (2027), §4.9.</ref><ref name="GL-55">Gottuk and Lattimer (2002), p. 2-55.</ref>

== How a flammable smoke cloud forms ==
Smoke is a mixture of solid particles, liquid droplets and gases. Besides combustion products and entrained air, it contains decomposition gases of the fuel.<ref name="VR-6.1">Van Rossum (2027), §6.1.</ref> When these unburnt pyrolysis gases mix with oxygen, they can ignite if the temperature is high enough or an ignition source is present.<ref name="VR-6.1" /> The amount of flammable gas in smoke therefore depends on how completely the fuel has burned.

Two kinds of fire produce smoke rich in fuel gases. The first is a [[ventilation-controlled fire]]. In such a fire the burning rate is limited by the supply of oxygen, and unburnt pyrolysis gases can escape into the smoke. Mixed with oxygen, they form a combustible mixture that needs only ignition energy to burn.<ref name="VR-4.8">Van Rossum (2027), §4.8.</ref>

In full-scale room fires, carbon monoxide levels of several per cent have been measured.<ref name="GL-54">Gottuk and Lattimer (2002), p. 2-54.</ref> In a worked example of a furniture fire short of air, the upper layer held 2.8 per cent carbon monoxide but only 0.5 per cent oxygen.<ref name="GL-80">Gottuk and Lattimer (2002), p. 2-80.</ref> Such a layer contains fuel but too little oxygen to burn on its own.

The second kind is a smouldering fire. Smouldering is a slow combustion process with low gas temperatures and no flames, and it can generate high levels of carbon monoxide.<ref name="GL-54" /> Without flames, the unburned fuel and carbon monoxide from a smouldering fire can build up to form a premixed combustible atmosphere.<ref name="IS-15-4" /> This is the route described for smoke explosions in polyurethane foam fires.<ref name="IS-15-4" />

The flammable gases in such smoke are products of [[incomplete combustion]]. In a handbook example of a hot smoke layer, they were unburned hydrocarbons, carbon monoxide and hydrogen.<ref name="B-184">Beyler (2002b), p. 2-184.</ref> A Dutch study lists methane, carbon monoxide, carbon dioxide and hydrogen among the usual combustion products released when the battery of an electric vehicle burns.<ref name="VdG-26">Van der Graaf et al. (2021/2023), p. 26.</ref> Before such a cloud can explode, it must be diluted with enough air to fall within its flammable range, but not so much that it falls below it.<ref name="IS-15-4" />

== Flammability limits and mixtures of gases ==
A premixed gas can only carry a flame within a certain range of composition. The boundaries of this range are the lower and upper explosion limits, also called the lower and upper [[flammability limits]].<ref name="IS-15-4" /> Outside the range the mixture is not explosive. At the limits it burns with only a weak flame, and somewhere between the limits the flame spreads fastest.<ref name="IS-15-4" /> For methane in air at normal temperature and pressure the limits are 5 and 15 per cent by volume. For most simple hydrocarbons the lower and upper limits correspond to equivalence ratios of about 0.5 and 3.<ref name="B-172">Beyler (2002b), p. 2-172.</ref>

Limits of some gases found in smoke are listed in the SFPE Handbook. Carbon monoxide burns in air between 12.5 and 74 per cent, hydrogen between 4.0 and 75 per cent, and hydrogen cyanide between 5.6 and 40 per cent.<ref name="B-175">Beyler (2002b), pp. 2-175–2-176.</ref> The autoignition temperatures in the same table are 400 °C for hydrogen and 540 °C for methane.<ref name="B-175" /> The limits widen as the temperature of the mixture rises.<ref name="B-174">Beyler (2002b), p. 2-174.</ref> More oxygen raises the upper limit, while the lower limit hardly changes, because a lean mixture already has more oxygen than it needs.<ref name="B-174" />

Fire gases are mixtures of several fuels. The lower flammability limit of such a mixture can be estimated with an empirical rule of Le Chatelier.<ref name="B-174" /> Each fuel gas contributes to the flammability in proportion to its share of the fuel mixture, divided by its own lower limit:

<math display="block">\mathrm{LFL}_m = \frac{100}{\sum_{i=1}^{n} C_{f,i} / \mathrm{LFL}_i}</math>

{| class="wikitable"
! Symbol !! Description !! Unit
|-
| <math>\mathrm{LFL}_m</math> || lower flammability limit of the fuel gas mixture in air || vol %
|-
| <math>C_{f,i}</math> || share of fuel gas <math>i</math> in the fuel gas mixture (the shares add up to 100) || vol %
|-
| <math>\mathrm{LFL}_i</math> || lower flammability limit of fuel gas <math>i</math> alone in air || vol %
|-
| <math>n</math> || number of fuel gases in the mixture || –
|}

The handbook gives a worked example for a fuel gas of 50 per cent methane, 25 per cent carbon monoxide and 25 per cent hydrogen. All three gases occur in fire gases, for example in the gases released by burning vehicle batteries.<ref name="VdG-26" /> Their lower limits are 5.0, 12.5 and 4.0 per cent respectively.<ref name="B-174" />

<math display="block">\mathrm{LFL}_m = \frac{100}{50/5 + 25/12.5 + 25/4} = \frac{100}{18.25} = 5.48\ \%</math>

At the lower limit, the mixture therefore contains 2.74 per cent methane, 1.37 per cent carbon monoxide, 1.37 per cent hydrogen and 94.5 per cent air.<ref name="B-177">Beyler (2002b), p. 2-177.</ref> Carbon monoxide alone would need 12.5 per cent before it could burn, so the more reactive gases lower the limit of the mixture considerably.<ref name="B-175" /> The rule applies to mixtures of flammable gases in air. Smoke also contains inert gases such as carbon dioxide and nitrogen, and the flammability limits depend on the oxygen and inert gas concentrations as well as on the fuel.<ref name="B-173">Beyler (2002b), p. 2-173.</ref><ref name="B-184" />

Inert gases set a second limit. Below a limiting oxygen concentration, a premixed flame cannot spread whatever the amount of fuel.<ref name="B-179">Beyler (2002b), p. 2-179.</ref> With nitrogen as diluent this concentration is generally 10 to 12 per cent oxygen, lower for carbon monoxide and hydrogen, and 2 to 3 per cent higher with carbon dioxide as diluent.<ref name="B-179" /> A smoke cloud must therefore contain both enough fuel and enough oxygen to be within its flammable range.<ref name="B-179" />

== Ignition and deflagration ==
A smoke explosion needs the same three elements as any deflagration in a building: a flammable mixture of fuel and oxygen, a means of ignition and an enclosure.<ref name="IS-15-3">Iqbal and Salley (2004), p. 15-3.</ref> The mixture can ignite by autoignition, for example when a smouldering fire heats it to its autoignition temperature.<ref name="IS-15-4" /> It can also be ignited by a spark from an electrical installation or by glowing particles from the fire.<ref name="VR-4.10" /> In a study of smoke explosions in a reduced-scale enclosure with a smouldering wood crib, the change from smouldering to flaming was suggested as the trigger. The evidence for this was indirect.<ref name="O-208">Ohlemiller (2002), p. 2-208.</ref>

Once ignited, the flame runs through the premixed cloud as a [[premixed flame]], like the flame of a gas burner in which fuel and air are mixed before ignition.<ref name="VR-4.3">Van Rossum (2027), §4.3.</ref> In a deflagration, the flame front travels below the speed of sound, which is about 330 m/s in air at 20 °C. In a detonation it moves at about 2000 m/s and drives a shock wave.<ref name="IS-15-3" /> Laminar burning velocities of fuels are far lower, about 40 cm/s for methane and 312 cm/s for hydrogen.<ref name="Z-407">Zalosh (2002), p. 3-407.</ref> The burning gas expands as it heats up, and in an enclosed space this expansion raises the pressure.<ref name="Z-406">Zalosh (2002), p. 3-406.</ref><ref name="IS-15-5">Iqbal and Salley (2004), p. 15-5.</ref>

The time to reach the maximum pressure depends on the size of the enclosure and the fuel, and can be up to a few hundred milliseconds.<ref name="IS-15-3" /> Normal openings in an enclosure usually vent some gas but are usually too small to prevent destructive pressures.<ref name="IS-15-3" /> When gas escapes through a door or window, the resulting turbulence can produce a second pressure peak.<ref name="IS-15-5" />

== Pressures and consequences ==
Ordinary fires seldom create high pressures. The NRC guide notes that, apart from smoke gas explosions, fires rarely reach the pressures that injure people.<ref name="IS-15-12" /> If a premixed gas-air mixture is ignited inside a building, the pressure can reach a maximum of about 8 bar.<ref name="IS-15-12" />

In closed vessel tests, ten of twelve flammable gases and vapours reached maximum overpressures of 6.8 to 8.1 bar. Methane reached 7.1 bar.<ref name="Z-407" /> Calculated worst-case pressures of 8 to 9.6 atmospheres absolute occur at mixtures slightly richer than stoichiometric. Near the flammability limits, measured pressures are much lower than calculated, because only part of the gas burns and heat is lost to the walls.<ref name="Z-406" />

Buildings fail long before such pressures are reached. Typical failure pressures are 2 to 7 kPa for glass windows, 2 to 3 kPa for room doors and 2 to 5 kPa for light partition walls.<ref name="IS-15-13">Iqbal and Salley (2004), p. 15-13.</ref> Unrestrained brick walls fail at about 7 to 15 kPa.<ref name="IS-15-13" /> A pressure of 8 bar equals 800 kPa, more than a hundred times the failure pressure of a window. Even a partial explosion of a smoke cloud can therefore break windows, doors and partitions.

The effects on people depend on the pressure and on what is thrown about. The limit for eardrum rupture is about 35 kPa and for lung damage about 70 kPa, while 1 per cent mortality is expected at about 180 kPa.<ref name="IS-15-12" /> When people are killed by blast waves, it is usually by falling objects rather than by the pressure itself.<ref name="IS-15-12" /> After ignition, the flame front travels through the whole mixture.<ref name="IS-15-6">Iqbal and Salley (2004), p. 15-6.</ref> The hazards of a deflagration include the ejection of flame and unburned product into the surroundings, possible secondary explosions and personal injury.<ref name="IS-15-3" />

== Related phenomena ==
Backdraft and smoke explosion both involve fuel-rich smoke and air, but in a different order. In a backdraft, gases build up in a closed room during an oxygen-starved fire. When fresh air suddenly enters, for example through an opened door, the gases burn explosively and can produce a large fireball.<ref name="VR-4.9" /> If the smoke is cool, ignition is delayed until fresh air has mixed with the smoke and reached the fire, which then acts as the ignition source.<ref name="IS-15-4" /> The NRC guide notes that a backdraft explosion has the characteristics of a premixed fuel and air deflagration.<ref name="IS-15-4" />

In a smoke explosion, the fuel and air are already mixed before any ignition source acts.<ref name="VR-4.10" /> No sudden opening is needed, and the cloud can be ignited by its own temperature or by a spark.<ref name="IS-15-4" /> Rollover, by contrast, is the burning of fuel-rich gases at the boundary between the smoke layer and the air below it. It occurs during underventilated burning and does not involve a premixed cloud.<ref name="GL-55" />

The NRC guide groups gas explosions and backdraft explosions with dust explosions as combustion explosions.<ref name="IS-15-2">Iqbal and Salley (2004), p. 15-2.</ref> All of them involve a rapid release of high-pressure gas that forms a pressure wave.<ref name="IS-15-2" /> Physical explosions, such as the failure of a tank heated from outside, form a separate group in which the high-pressure gas is produced without a chemical reaction.<ref name="IS-15-2" />

== Electric vehicles and battery gases ==
A newer source of explosive fire gases is the thermal runaway of lithium-ion batteries. A Dutch study by the Netherlands Institute for Public Safety (2021) describes how battery cells release gases when they go into thermal runaway.<ref name="VdG-27">Van der Graaf et al. (2021/2023), p. 27.</ref> If these gases are not ignited at once, an explosive mixture of fire gases can build up in a confined, enclosed or poorly ventilated space. When the lower explosion limit is reached and the mixture is ignited, a fire gas explosion can occur.<ref name="VdG-27" />

The same study notes that gases escaping from a battery pack can lead to a flare fire or a gas cloud explosion when they are in the right mixing ratio.<ref name="VdG-22">Van der Graaf et al. (2021/2023), p. 22.</ref> Fires in electric vehicles can involve repeated minor explosions, flying parts and flash fire.<ref name="VdG-29">Van der Graaf et al. (2021/2023), p. 29.</ref> A thermal runaway without direct ignition of its gases can result in a fire gas explosion once the lower explosion limit is reached and an ignition source is present.<ref name="VdG-29" /> These findings concern indoor car parks in the Netherlands.<ref name="VdG-27" />

== Limits of prediction ==
The pressure produced by an explosion is usually difficult to predict, and its effects on people depend strongly on nearby objects that can be thrown.<ref name="IS-15-12" /> The flammability limits in tables apply to well-mixed gases at normal temperature and pressure. They change with temperature, oxygen content and inert gases.<ref name="B-174" /> Smoke that flows away from a fire is cooled by mixing with surrounding gases and by heat losses to the walls, so its temperature and composition change along the way.<ref name="GL-71">Gottuk and Lattimer (2002), p. 2-71.</ref>

Temperature also shifts the limits. A mixture can burn outside its flammability limits only if energy is supplied throughout its volume.<ref name="B-173" /> Preheating makes leaner mixtures burnable. In one experiment, a mixture of 1 per cent methane in air burned when preheated to 1270 K, although the lower limit at room temperature is 5 per cent.<ref name="B-177" /> Hot smoke can therefore be flammable at lower fuel concentrations than tables for room temperature suggest.<ref name="B-174" />

== See also ==
* [[Explosion]]
* [[Flashover]]
* [[Hot gas layer]]
* [[Fire-induced pressure]]

== Notes ==
<references />

== References ==
* Beyler, C. L. (2002b). Flammability limits of premixed and diffusion flames. In P. J. DiNenno, D. Drysdale, C. L. Beyler, W. D. Walton, R. L. P. Custer, J. R. Hall Jr., & J. M. Watts Jr. (Eds.), ''SFPE handbook of fire protection engineering'' (3rd ed., pp. 2-172–2-187). National Fire Protection Association; Society of Fire Protection Engineers.
* Gottuk, D. T., & Lattimer, B. Y. (2002). Effect of combustion conditions on species production. In P. J. DiNenno, D. Drysdale, C. L. Beyler, W. D. Walton, R. L. P. Custer, J. R. Hall Jr., & J. M. Watts Jr. (Eds.), ''SFPE handbook of fire protection engineering'' (3rd ed., pp. 2-54–2-82). National Fire Protection Association; Society of Fire Protection Engineers.
* Iqbal, N., & Salley, M. H. (2004). ''Fire Dynamics Tools (FDTs): Quantitative fire hazard analysis methods for the U.S. Nuclear Regulatory Commission Fire Protection Inspection Program'' (NUREG-1805). U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation.
* Ohlemiller, T. J. (2002). Smoldering combustion. In P. J. DiNenno, D. Drysdale, C. L. Beyler, W. D. Walton, R. L. P. Custer, J. R. Hall Jr., & J. M. Watts Jr. (Eds.), ''SFPE handbook of fire protection engineering'' (3rd ed., pp. 2-200–2-210). National Fire Protection Association; Society of Fire Protection Engineers.
* Van der Graaf, J., Hessels, T., & Rosmuller, N. (2023). ''Fire safety of indoor car parks accommodating electrically powered vehicles''. Nederlands Instituut Publieke Veiligheid. (Original work published 2021)
* Van Rossum, E. (2027). ''Introduction to Fire Safety Engineering''. Fire Safety Academy.
* Zalosh, R. (2002). Explosion protection. In P. J. DiNenno, D. Drysdale, C. L. Beyler, W. D. Walton, R. L. P. Custer, J. R. Hall Jr., & J. M. Watts Jr. (Eds.), ''SFPE handbook of fire protection engineering'' (3rd ed., pp. 3-402–3-421). National Fire Protection Association; Society of Fire Protection Engineers.

[[Category:Enclosure Fires]]