Flammable liquid
Flammable liquid means any liquid having a vapor pressure not exceeding 40 pounds per square inch (absolute) at 100 F (37.8 C) and having a flashpoint at or below 199.4 F (93 C). Flammable liquids are divided into four categories as follows:
(1) Category 1 shall include liquids having flashpoints below 73.4 °F (23 °C) and having a boiling point at or below 95 °F (35 °C).
(2) Category 2 shall include liquids having flashpoints below 73.4 °F (23 °C) and having a boiling point above 95 °F (35 °C).
(3) Category 3 shall include liquids having flashpoints at or above 73.4 °F (23 °C) and at or below 140 °F (60 °C).
(4) Category 4 shall include liquids having flashpoints above 140 °F (60 °C) and at or below 199.4 °F (93 °C).
(i) Flash point of the liquid means the temperature at which it gives off vapor sufficient to form an ignitable mixture with the air near the surface of the liquid or within the vessel used as determined by appropriate test procedure and apparatus as specified below.
(1) The flashpoint of liquids having a viscosity less than 45 Saybolt Universal Second(s) at 100 °F (37.8 °C) and a flashpoint below 175 °F (79.4 °C) shall be determined in accordance with the Standard Method of Test for Flash Point by the Tag Closed Tester, ASTM D-56-69 (incorporated by reference; See § 1926.6), or an equivalent method as defined by § 1910.1200 appendix B.
(2) The flashpoints of liquids having a viscosity of 45 Saybolt Universal Second(s) or more at 175 °F (79.4 °C) or higher shall be determined in accordance with the Standard Method of Test for Flash Point by the Pensky Martens Closed Tester, ASTM D-93-69 (incorporated by reference; See § 1926.6), or an equivalent method as defined by § 1910.1200 appendix B.
(j) Liquefied petroleum gases, LPG and LP Gas mean and include any material which is composed predominantly of any of the following hydrocarbons, or mixtures of them, such as propane, propylene, butane (normal butane or iso-butane), and butylenes.
(k) Portable tank means a closed container having a liquid capacity more than 60 U.S. gallons, and not intended for fixed installation.
(l) Safety can means an approved closed container, of not more than 5 gallons capacity, having a flash-arresting screen, spring-closing lid and spout cover and so designed that it will safely relieve internal pressure when subjected to fire exposure.
(m) Vapor pressure means the pressure, measured in pounds per square inch (absolute), exerted by a volatile liquid as determined by the “Standard Method of Test for Vapor Pressure of Petroleum Products (Reid Method).” (ASTM D-323-58).
Source
29 CFR § 1926.155
Scoping language
Approved, for the purpose of this subpart, means equipment that has been listed or approved by a nationally recognized testing laboratory such as Factory Mutual Engineering Corp., or Underwriters' Laboratories, Inc., or Federal agencies such as Bureau of Mines, or U.S. Coast Guard, which issue approvals for such equipment.