Detonation + Deflagration

When specifying for fire resistance, there are two types of information you might find yourself regularly noticing: Detonation and Deflagration.

What is the difference?

DETONATION is a quick and explosive form of fire.

Detonation is usually caused by a reaction from a combination of chemicals. It is characterized by a supersonic exothermic front with significant overpressure. Examples inc. TNT, Nitroglycerine, Dynamite, Picric acid and C4.


DEFLAGRATION is a slow catching fire.

Ordinary fire and most explosions are instances of deflagration. Deflagration fires are usually controllable and can be harnessed. Examples inc. Internal combustion engine, Gas Stove, Fireworks and Pyrotechnics, Gunpowder, Grease or Chip Pan Fire.

And why?

To further understand, and remember why this is, it’s necessary to look at the roots of the words involved to help uncover the difference and meaning behind the concepts involved…


What is Ignition? (n)

The action or process or setting something on fire and/or starting to burn. It denotes the heating of a substance to the point of combustion or chemical

What is Combustion? (n)

The process of something burning something. In chemistry, Combustion is the rapid chemical combination of a substance mixed with oxygen involving heat and light. Combustion can happen at both the start of either a small sustained fire or a large sudden explosion.

What is an Explosion? (n)

An abrupt and violent expansion in which energy is transmitted outwards as a shockwave leading to an eruption. Explosions are usually caused by bombs in which carry a volatile elemental mix.

What is a Blast?

 (n) A fast and destructive wave of compressed air project spreading outwards to form an explosion

(v) The process of something breaking apart and blowing up with explosive.


Combustion takes different forms. When a decomposition reaction or combination reaction releases a lot of energy in a very short span of time, an explosion may occur. Deflagration and detonation are two ways energy may be released. If the combustion process propagates outward at subsonic speeds, it’s a deflagration. If the explosion moves outward at supersonic speeds, it’s a detonation.

Blast Resistance

Blast Resistant tests are frequently conducted and rated by assessing resilience to the use of heavy TNT explosions.

Bullet Resistance

Ballistic protection is the name for products that are designed to be bullet/ballistic resistant when under attack by firearms, including the use of pistols, assault rifles, and shotguns. The protection is rated using the European (EN) Standards, which specify the weapons and types of prolonged damage available

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