Propane

OriginDerived from petroleum crude oil or natural gas through fractional distillation processes. Produced synthetically via thermal or catalytic cracking of hydrocarbons into three-carbon alkane molecules.

Propane appears as a colorless gas with a faint petroleum-like odor. It is shipped as a liquefied gas under its vapor pressure. For transportation it may be stenched. Contact with the unconfined liquid can cause frostbite by evaporative cooling. Easily ignited. The vapors are heavier than air and a flame can flash back to the source of leak very easily. The leak may be either a liquid or vapor leak. The vapors can asphyxiate by the displacement of air. Under prolonged exposure to fire or heat the containers may rupture violently and rocket.

The paper trail

Counts, not a verdict. A listing isn't a study. The trail, you decide.