At what flashpoint is a liquid classified as flammable?

The classification of a liquid as flammable is determined by its flashpoint, which is the lowest temperature at which its vapor can ignite when exposed to an open flame or spark. A liquid is categorized as flammable when its flashpoint is less than 100 degrees Fahrenheit.

At a flashpoint under 100 degrees, the vapor produced by the liquid can ignite easily, posing a significant safety risk in various environments. This is why most regulatory agencies and fire safety standards define flammable liquids as those with flashpoints below this threshold.

In contrast, liquids with flashpoints above 100 degrees Fahrenheit are typically classified as combustible rather than flammable, as they require higher temperatures to produce ignitable vapors. This distinction is important in fire investigations and safety practices because it helps in assessing hazards and implementing appropriate precautionary measures when dealing with different types of liquids.