The above logistics model explains the difference between primary and secondary transport. It was estimated, in 2012, that the average footprint per tonne of cylinder LPG is about three times that of a tonne of bulk LPG. However, data reported in 2012 were not suffi ciently broken down to provide precise fi gures for footprints by product type, i.e. bulk, cylinder and wholesale.

Additional data collected in 2013 did enable a more precise comparison and this multiple turned out to be slightly lower than estimated. Cylinder LPG turned our to be 2,5 more carbon intensive than bulk LPG.