A flammable liquid is a

liquid A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. As such, it is one of the four fundamental states of matter (the others being solid, gas, a ...

which can be easily ignited in air at ambient temperatures, i.e. it has a

flash point The flash point of a material is the "lowest liquid temperature at which, under certain standardized conditions, a liquid gives off vapours in a quantity such as to be capable of forming an ignitable vapour/air mixture". (EN 60079-10-1) The fl ...

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 large regulatory agency of the United States Department of Labor that originally had federal visitorial powers to inspect and examine workplaces. Congress established the agenc ...

(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, unemploym ...

defines a liquid as flammable if it has a flash point at or below 199.4 °F (93 °C). Prior to bringing regulations in line with the United Nations

Globally Harmonized System of Classification and Labeling of Chemicals The Globally Harmonized System of Classification and Labelling of Chemicals (GHS) is an internationally agreed-upon standard managed by the United Nations that was set up to replace the assortment of hazardous material classification and labelli ...

(GHS) in 2012, OSHA considered flammable liquids to be those with a flash point below 100 °F (37.8 °C). Those with flash points above 100 °F and below 200 °F (93.3 °C) were classified as combustible liquids. Studies show that the actual measure of a liquid's flammability, its flash point, is dependent on altitude.

Categorization

Both OSHA and GHS further divide flammable liquids into 4 categories: * Category I flammable liquids are those with

boiling points The boiling point of a substance is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor. The boiling point of a liquid varies depending upon the surrounding envir ...

≤ 95 °F (35 °C) and flash points < 73 °F (23 °C) * Category II flammable liquids are those with boiling points > 95 °F and flash points < 73 °F * Category III flammable liquids are those with flash points > 73 °F and ≤ 140 °F (60 °C) * Category IV flammable liquids are those with flash points > 140 °F and ≤ 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 sheet A safety data sheet (SDS), material safety data sheet (MSDS), or product safety data sheet (PSDS) is a document that lists information relating to occupational safety and health for the use of various substances and products. SDSs are a widely ...

s, as follows:

References

Fuels {{explosive-stub

Categorization

Labeling

See also

References