As vehicle designs move further and further away from conventional gasoline-powered engines, alternative fuel vehicles are becoming more prevalent on the roadway, particularly in mass transportation and last-mile delivery services. Before fire investigators can properly determine origin and cause in alternative fuel vehicle fires, they must understand how these vehicles are designed and fueled. Although every vehicle is different, as is true with conventionally-fueled vehicles, there are many common elements that can ground the investigator's understanding of the basic principles of how alternative fuel vehicles work, how they convert the alternative fuel into power, and important implications of these alternative fuels for fire investigation. This program explains those basics for vehicles fueled by compressed natural gas (CNG), liquefied natural gas (LNG), propane (also known as liquefied petroleum gas, or LPG), and hydrogen (also known as fuel cell technology).

Please note that before approaching any alternative fuel vehicle, the fire investigator must ensure that the integrity of the fuel storage system and vehicle's power source have been disconnected and discharged (if applicable) and that safety procedures for the type of fuel have been and continue to be observed.

IMPORTANT SAFETY WARNING: A fire investigation involving an alternative fuel vehicle SHOULD NOT proceed unless the vehicle has been made safe according to the manufacturer's instructions for that specific vehicle make/model/year.