combustible gas; flammable gas
Technical and general term for any gas that can ignite or burn. Used in safety contexts, chemistry, and everyday warnings.
The use of flammable gas is prohibited in this area.
There is a possibility of flammable gas leaking, so please ventilate immediately.
Compound of 可燃性 (combustibility) + ガス (gas). 可燃性 is from 可 (possible) + 燃 (burn) + 性 (property).