Celluloid
Because fuel is a FLAMMABLE material.
flammable material
Class 3 Flammable Liquid label
Class 3 Flammable Liquid label
Combustible or Flammable
Flammable
gas cylinders , geysers , electric circuits are some domestic material which are flammable.
Flammable Material
Class 3 covers flammable liquids.
A flammable material has a lower flash point (100F or below) while a combustible material has a flash point of 100F or HIGHER. In other words, it's a lot easier for a flammable material to catch fire than a combustible one because of the minimal amount of energy (heat) required to get it going versus the higher requirement of a combustible material.
It means the material is easy to be burnt and should be kept away from fire.