All gases such as hydrogen, methane and propane, which can form ignitable mixtures in air, are classed as flammable gases. Because they contain gases under pressure and the contents are flammable, cylinders of these gases carry both the compressed gas and the flammable material symbols. Flammable Liquids Liquids which present an extreme fire hazard are called flammable liquids. Flammable liquids present a fire hazard at or below room temperature. A spark or other ignition source can easily ignite the vapour present over a flammable liquid.
Gasoline is a typical flammable liquid.
These chemicals are found in countless products ranging from adhesives to cleaners and paints. Flammable liquids are also quite commonly used in Dalhousie's research laboratories. Combustible Liquids Combustible liquids also present a fire hazard. So, combustible liquids are more difficult to ignite than flammable liquids. Although Varsol can create a serious fire hazard, it does have to be heated to slightly above 40 C before there is enough vapour present to create a fire.