Early models were often filled with highly flammable substances.
"There was a flammable substance poured onto the stage."
The police said a flammable substance, possibly gasoline, was used.
White gas is a common name for two flammable substances.
The surface may not heat up significantly, allowing the coating of flammable substances.
A trough containing a flammable substance is used for lighting.
Be careful with any flammable substances used to start fires, such as lighter fluid.
Could the dress have been exposed to any flammable substances?
Someone had burned a flammable substance recently, possibly newspapers or magazines.
These were added to the flammable substance to cause it to gel.