Definition - What does flammable liquids mean?
Flammable liquids are liquids which can burn. A liquid is classified as flammable if its flash point is below 100°F or 37.8°C. Flash point can be defined as the lowest temperature at which a liquid gives off sufficient vapor to ignite. Hence, the flash point of a liquid plays an important role in determining it as flammable or combustible. The main distinction between flammable and combustible liquids is that the former can catch on fire at normal working temperatures, whereas the later has the ability to ignite at higher working temperatures.
Petropedia explains flammable liquids
In oil and gas industry, there are many types of flammable liquids. Basically, a flammable liquid is defined as any liquid that has the potential to burn. Flammable liquids have a flash point below 100 degrees Fahrenheit (37.8°C), whereas the combustible liquids are less-flammable with a flash point above 37.8°C. Every flammable liquid has a flammable limit that is measured in upper and lower limits. Fuels produced from oil refineries are common examples of flammable liquids. Other examples include paints, solvents, cleaners and thinners.