what is flash point

1 year ago 92

Flash point is the lowest temperature at which a liquid gives off vapors in a quantity such as to be capable of forming an ignitable vapor/air mixture. In other words, it is the temperature at which a liquid will generate sufficient vapor to flash (ignite) when exposed to a source of ignition or fire. The flash point is a convenient and reliable classification of the flammability of many substances.

Some key points about flash point are:

The flash point is an empirical measurement rather than a fundamental physical parameter. The measured value will vary with equipment and test protocol variations, including temperature ramp rate, time allowed for the sample to equilibrate, sample volume, and whether the sample is stirred.
There are two basic types of flash point measurement: open cup and closed cup. In open cup devices, the sample is contained in an open cup which is heated and, at intervals, a flame brought over the surface. The measured flash point will actually vary with the height of the flame above the liquid surface and, at sufficient height, the measured flash point temperature will coincide with the fire point. The best-known example is the Cleveland open cup (COC).
The flash point is used in shipping and safety regulations to define flammable and combustible materials and classify their hazard potential, which has significant cost implications when transporting or storing products. Petroleum and chemical industries often use flash point testing to check for contamination or adulteration of a product.
The flash point is an important parameter in oil analysis. Blackstone Laboratories, for example, uses the flashpoint test to determine how much fuel dilution is present in oil. Each brand/type of oil has an expected “should be” value for the flashpoint, and when the lab test results read lower than that value, it shows a contaminant in the oil.

Representative liquids and their approximate flash points are: