The term flammable liquid means any liquid which gives off flammable vapors (as determined by flashpoint from an open cup tester, as used for test of burning oils) at or below a temperature of 80 °F. Flammable liquids are referred to by grades as follows:
(1) Grade A.
Any flammable liquid having a Reid 1 vapor pressure of 14 pounds or more.
1 American Society of Testing Materials Standard D 323 (incorporated by reference, see § 105.01-3
) (most recent revision), Method of Test for Vapor Pressure of Petroleum Products (Reid Method).
(2) Grade B.
Any flammable liquid having a Reid 1 vapor pressure under 14 pounds and over 8 1/2 pounds.
(3) Grade C.
Any flammable liquid having a Reid 1 vapor pressure of 8 1/2 pounds or less and a flashpoint of 80 °F. or below.
[CGFR 69-53, 34 FR 11265, July 4, 1969, as amended by CGD 73-96, 42 FR 49025, Sept. 26, 1977; USCG-2000-7790, 65 FR 58461, Sept. 29, 2000]