What is the definition of flammable liquids?

Flammable liquids are defined primarily by their flashpoint, which is the temperature at which a liquid produces enough vapor to form an ignitable mixture with air. When a liquid has a flashpoint below 100°F, it indicates that it can easily ignite under standard conditions, making it a significant fire hazard. This is critical information for fire inspectors and safety personnel, as identifying and managing the risks associated with flammable liquids is essential for ensuring safety in various environments.

Other criteria, such as boiling point, vapor pressure, and ignition point, are relevant to the overall understanding of chemical properties and fire behavior, but they do not specifically define flammable liquids. For example, a boiling point above 100°F does not necessarily indicate flammability. Similarly, vapor pressure below atmospheric pressure is not a defining characteristic of flammable liquids, nor does an ignition point above 200°F determine their flammability. Understanding the significance of flashpoint in determining flammability is crucial for appropriate fire safety measures and regulations.