As used in ORS 480.420 to 480.460, “LP gas” or “liquefied petroleum gas” means any liquid composed predominantly of any of the following hydrocarbons or mixtures of the same: Propane, propylene, butanes (normal butane or isobutane) and butylenes. [Amended by 1957 c.712 §1; 2009 c.790 §3]