Abstract:
The significance of the presence of petrol in motor vehicle fires has often been challenged due to the possibility of a natural
occurrence of petrol residues inside the vehicle. Transfer and persistence studies were undertaken to investigate the potential
transfer and persistence of petrol onto vehicle carpets through the 'normal' usage of motor vehicles.
The results of the transfer study indicate that petrol may be transferred from the external environment in sufficient quantities
via the shoes of drivers or passengers to be detected after a 24 h period, but not after I week. Low levels of petrol were detectable
after 24 h on all carpet mats where the initial volume was 500 ul. or more. The level of evaporation of the petrol detected
increased with corresponding increases in the time period between transfer and analysis.
The results of the persistence study indicate that small volumes of petrol (less than 100 ul.) are unlikely to be detected on
carpet after a 24 h period. and volumes of less than 1000 ul, are unlikely to be detected on acoustic padding after this time period.
Larger volumes may be detected after this period. but will generally not be detectable on either carpet or acoustic padding after 4
weeks. In each case. the petrol that is detected exhibits a chromatographic profile of greater than 60% evaporated petrol.
These results demonstrate the significance of finding a large volume of fresh or slightly evaporated petrol on car carpet.
