Accelerator (chemistry)

Accelerants are substances that can bond, mix or disturb another substance and cause an increase in the speed of a natural, or artificial chemical process. Accelerants play a major role in chemistry—most chemical reactions can be hastened with an accelerant. Accelerants alter a chemical bond, speed up a chemical process, or bring organisms back to homeostasis. Accelerants are not necessarily catalysts as they may be consumed by the process.

In fire protection, the term accelerant is used very broadly to include any substance or mixture that "accelerates" the development of fire to commit arson. Chemists would distinguish an accelerant from a fuel; the terms are not, in the truest sense of chemical science, interchangeable. Some fire investigators use the term "accelerant" to mean any substance that initiates and promotes a fire without differentiating between an accelerant and a fuel. To a chemical engineer, "gasoline" is not at all considered an "accelerant;" it is more accurately considered a "fuel."

A fire is a self-sustaining, exothermic oxidation reaction that emits heat and light. When a fire is accelerated with a true accelerant like oxygen bearing liquids and gases (like NO
₂) it can produce more heat, consume the actual fuels more quickly, and increase the spread of the fire. Fires involving liquid accelerants, like gasoline, burn more quickly, but at the same temperature as fires involving ordinary fuels.

Indicators of an incendiary fire or arson can lead fire investigators to look for the presence of fuel traces in fire debris. Burning compounds and liquids can leave behind evidence of their presence and use. Fuels present in areas they aren't typically found in can indicate an incendiary fire or arson. Investigators often use special dogs known as "accelerant detection canines" trained to smell ignitable liquids. Well-trained dogs can pinpoint areas for the investigator to collect samples. Fire debris submitted to forensic laboratories employ sensitive analytical instruments with GC-MS capabilities for forensic chemical analysis.

...
Wikipedia