The Flamethrower Fuel (火炎放射器の燃料,Kaen hōsha-ki no nenryō?) was an item that was ultimately removed from the final cut of the original Resident Evil. It would appear that the Flamethrower used in the game was to be usable for much longer than it ultimately did. The Flamethrower Fuel is also in Resident Evil 1.5 and the Resident Evil 2: Trial version (final), though its coding is unused in-game.
Like the Dumdum Rounds, Flamethrower Fuel is accessible with a cheat device or via data editing in the early releases of Resident Evil 1.