What is the definition of flashpoint in fire safety?

Flashpoint is defined as the lowest temperature at which the vapor of a liquid can ignite in air when exposed to an ignition source. This measure is critical in fire safety because it helps to identify the flammability of substances, which is essential for safe handling and storage.

Understanding flashpoint is vital for determining how a liquid behaves under different temperature conditions, as vapors produced by the liquid can mix with air to form an ignitable mixture. If the temperature is below this threshold, the vapor concentration will not be sufficient to ignite, making it safer to handle compared to liquids with a lower flashpoint, where hazards are present at more common temperatures.

The other definitions provided do not accurately reflect the concept of flashpoint, as they pertain to different aspects of fire safety and combustion phenomena. Recognizing and adhering to flashpoint limits is critical for maintaining safe operations in environments where flammable liquids and vapors are present.