For the purpose of this subpart the term ``liquefied petroleum gas'' means any liquefied flammable gas which is composed predominantly of hydrocarbons or mixtures of hydrocarbons, such as propane, propylene, butane, butylene, or butadiene, and which has a Reid ASTM D 323 (incorporated by reference, see Sec. 58.03-1). Method of test for Vapor Pressure of Petroleum Products (Reid Method)) vapor pressure exceeding 40 pounds per square inch absolute at 100 [deg]F. [CGFR 68-82, 33 FR 18878, Dec. 18, 1968, as amended by USCG-2000-7790, 65 FR 58460, Sept. 29, 2000]