What defines a flammable liquid according to the flash point measurement?

A flammable liquid is defined by its flash point, which is the lowest temperature at which it can vaporize to form an ignitable mixture in air. The correct definition identifies a liquid with a flash point of not more than 70 degrees Fahrenheit. This threshold for flammability is significant because it helps in assessing the safety and handling procedures required for various liquids in different environments.

When considering the other definitions: a liquid with a flash point of 60 degrees Fahrenheit would categorize it as more hazardous and often included within the flammable liquids classification; however, 70 degrees Fahrenheit is a broader industry standard. Simply stating that a liquid burns steadily at room temperature does not specify a flash point and does not account for the conditions under which ignition may occur. Likewise, spontaneous combustion refers to materials that ignite without an external ignition source, which is a separate classification and does not align with the flash point criteria for flammable liquids.

Thus, classifying a liquid as flammable based on a flash point of not more than 70 degrees Fahrenheit provides a clear and consistent measurement for safety standards in handling and storage.