Risk assessment on life safety and financial loss for road accident of fuel cell vehicles

Vehicular use of hydrogen is the first attempt to apply hydrogen energy in consumers’ environment in large scale, though hydrogen has been widely used in industrial field for over one hundred years. The increasing number of hydrogen fuel cell vehicles has raised safety concerns in both public authorities and private bodies such as fire services and insurance companies. This paper analyzes typical accident progressions of hydrogen fuel cell vehicles in a road accident. Major hydrogen consequences including impinging jet fires and catastrophic tank ruptures are evaluated separately in terms of accident duration and hazard distances. Results show that in a 70 MPa fuel cell car accident, the hazards associated with hydrogen releases would normally last for no more than 1.5 minutes due to the empty of the tank. This indicates the first responders would be able to approach the vehicle, conservatively, approximate two minutes after hearing the hissing sound as the hydrogen hazards have been eliminated. For the safety of general public, a perimeter of 100 meters is suggested to be set in the accident scene if no hissing sound is heard. However, the perimeter can be reduced to 10 meters once the hissing sound of hydrogen release is observed. For the first responders, if there’s no sigh of hydrogen release, they should stand at least 10 m away from the burning car, otherwise their risk of fatality would be over 50% in case of catastrophic tank rupture. Furthermore, risks of fatalities, injuries, and damages are all quantified in financial terms to assess the impacts of the hypothetical accidents. Results show that costs of fatalities and injuries contribute most to the overall financial loss, indicating the insurance premium of fatalities and injuries should be set higher than that of property loss.