A flammable liquid is a

liquid Liquid is a state of matter with a definite volume but no fixed shape. Liquids adapt to the shape of their container and are nearly incompressible, maintaining their volume even under pressure. The density of a liquid is usually close to th ...

which can be easily ignited in air at ambient temperatures, i.e. it has a flash point at or below nominal threshold temperatures defined by a number of national and international standards organisations. The

Occupational Safety and Health Administration The Occupational Safety and Health Administration (OSHA; ) is a regulatory agency of the United States Department of Labor that originally had federal visitorial powers to inspect and examine workplaces. The United States Congress established ...

(OSHA) of the

United States Department of Labor The United States Department of Labor (DOL) is one of the executive departments of the U.S. federal government. It is responsible for the administration of federal laws governing occupational safety and health, wage and hour standards, unemp ...

defines a liquid as flammable if it has a flash point at or below 93 °C/199.4 °F. Prior to bringing regulations in line with the United Nations Globally Harmonized System of Classification and Labeling of Chemicals (GHS) in 2012, OSHA considered flammable liquids to be those with a flash point below 37.8 °C/100 °F. Those with flash points above 37.8 °C/100 °F and below 93.3 °C/200 °F were classified as combustible liquids. Studies show that the actual measure of a liquid's flammability, its flash point, is dependent on the local air pressure, meaning that at higher altitudes where the air pressure is lower, the flash point is also lower.

Categorization

Both OSHA and GHS further divide flammable liquids into 4 categories: * Category I flammable liquids are those with boiling points ≤ 35 °C/95 °F and flash points < 23 °C/73 °F * Category II flammable liquids are those with boiling points > 35 °C/95 °F and flash points < 23 °C/73 °F * Category III flammable liquids are those with flash points > 23 °C/73 °F and ≤ 60 °C/140 °F * Category IV flammable liquids are those with flash points > 60 °C/140 °F and ≤ 93 °C/199.4 °F These categorizations are dependent upon a set altitude and atmospheric pressure, as both boiling point and flash point change with changes in pressure.

Labeling

Both GHS and OSHA require the labeling of flammable liquids, on containers and safety data sheets, as follows:

References

Fuels {{explosive-stub

Categorization

Labeling

See also

References