What is the definition of an accelerant?

An accelerant is defined as a substance that increases the speed of a chemical reaction, particularly in the context of fire. In fire investigation, accelerants are typically flammable liquids that are intentionally used to enhance or propagate fire. Examples include gasoline, lighter fluid, or other petroleum-based products. Understanding the role of accelerants is critical for forensic analysts and investigators when determining the cause or origin of a fire, as their presence can indicate arson or the deliberate setting of a fire.

The other options reflect misunderstandings of the term. While a tool used to start a fire might play a role in ignition, it lacks the chemical nature of an accelerant. A fire extinguisher serves to suppress fire rather than initiate or speed up the combustion process, which is contrary to the purpose of an accelerant. Lastly, materials used for building structures have no relation to the act of accelerating a fire or its chemical reactions. Therefore, the correct answer accurately captures the essential characteristic of what an accelerant is in the context of fire investigations.