OSHA’s proposed revised rules dealing with flammable liquids were published in the Federal Register volume 74, number 188 dated September 30, 2009. The proposals in response to the Globally Harmonized System of Classification and Labeling of Chemicals (or GHS) would change labor law in the U.S. The main elements of the hazard classifications are summarized as: physical hazards, health hazards and environmental hazards.
Squarely in the middle of Physical Hazards we read, “A flammable liquid is a liquid with a flash point at or below 199.4 degrees F (93ºC).” Substances and mixtures of this hazard class are assigned to one of four hazard categories on the basis of the flash point and boiling point. Flash point means the minimum temperature of a liquid at which sufficient vapor is given off to form an ignitable mixture with the air, near the surface of the liquid or within the vessel used. Boiling point means the temperature at which the vapor pressure of a liquid equals the surrounding atmospheric pressure.