Ignition sources pyrophoric materials

Capable of igniting and burning in air without the presence of an ignition source. Pyrophoric materials are spontaneously combustible, although some pyrophorics require the presence of a minimum amount of moisture (humidity) to spontaneously ignite. Other spontaneously combustible substances and mixtures may require more time or an insulating environment to self-heat to the point of ignition. 

Spontaneously Combustible and Pyrophoric Substances Spontaneously combustible substances will readily react with the oxygen in the atmosphere, igniting and burning even without an ignition source. Ignition may be immediate, or may result from a self-heating process that may take minutes or hours (hence, some spontaneously combustible substances are known as self-heating materials). 

Based on material testing and other laboratory work, TCS DPR is not to be considered pyrophoric. This is primarily because of the absence of SiH-containing disilanes. However, these streams can form shock-sensitive hydrolysis products, which can be an ignition source for flammable atmospheres in the vicinity of the gel. 

Some sources of ignition can be discounted immediately this example, for instance, does not involve pyrophoric materials. As there are no vent lines leading to atmosphere, there is no danger from sources of ignition outside the plant. In practice, the presence of naked flames can also usually be discounted as they will normally be excluded from areas where flammable materials are handled. All electrical equipment should be checked to ensure that it is suitable for the area classification in which it is sited. 

A material that when in contact with air and without an energy source, is liable to self-heat. Tested in accordance with paragraph 3.b (1) of Appendix E, 49 CFR 173.124, i.e., if during a 24-hour test period the material spontaneously ignites or exhibits a temperature of 200°C. See also Pyrophoric Material Spontaneous Combustible Material. 

External fire. May be prompted by flammable gas or vapor liquid, solid, metal, wood, or waste material pyrophoric material and presence of ignition source such as sparks, static, friction, hot spots, welding, lightning, auto ignition, or furnace. Immediate consequence engulfment, thermal radiation, fire damage, smoke, domino effect (where one incident is the primary cause for several other incidents). 

PYROPHORIC SUBSTANCE A material that undergoes such vigorous oxidation or hydrolysis (often with evolution of highly-flammable gases) when exposed to atmospheric oxygen or to water, that it rapidly ignites without an external source of ignition. This is a special case of spontaneous combustion. 

Auto-ignition This is the temperature at which materials burn without a source of ignition. Gasoline auto-ignites at 450°R Asphalt auto-ignites at 320°F, methane at 1000°R The heavier the hydrocarbon, the lower the auto-ignition temperature. Iron sulfide (pyrophoric iron) burns at room temperature when it is dry. 

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