What does the flash point of a flammable liquid indicate?

The flash point of a flammable liquid is the temperature at which the liquid produces enough vapor to form an ignitable mixture with air. This is a critical characteristic for assessing the fire hazard associated with the liquid. At or above this temperature, the concentration of vapor in the air can ignite if an ignition source is present, leading to a potential fire or explosion risk.

Understanding the flash point is essential for safety in handling and storing flammable liquids, as it informs operators about the conditions under which fire hazards become relevant. For example, a liquid with a low flash point poses a higher risk in environments where temperatures can reach this point.

The other choices delineate different concepts related to flammability and heat but do not accurately describe the significance of the flash point. The highest temperature at which a substance ignites refers to a different point in flammability assessment, while the lowest temperature for safe storage does not directly relate to the properties of vaporization and ignition. The boiling point is also a separate physical property and does not indicate the potential for vapor ignition.