Propane is a 3 carbon alkane gas. It is stored under pressure inside a tank as a colourless, odourless liquid. As pressure is released, the liquid propane vaporizes and turns into gas that is used in combustion. An odorant, ethyl mercaptan, is added for leak detection. Propane seems as a colourless gas with a faint petroleum-like odour. It’s shipped as a liquefied gas beneath its force per unit area. For transportation it should be stenched. Contact with the unconfined liquid will cause trauma by state change cooling. Simply lighted. The vapors are heavier than air and a flame will come back to the supply of leak terribly simply. The leak could also be either a liquid or vapor leak. The vapors will asphyxiate by the displacement of air. Beneath prolonged exposure to fireside or heat the containers might rupture violently and rocket.