Which is true about the flash point of a liquid?

The flash point of a liquid is defined as the minimum temperature at which the liquid can produce enough vapor to ignite when exposed to an ignition source. This means at or above the flash point, the concentration of vapors in the air is sufficient to form a flammable mixture, leading to the potential for combustion if an ignition source is present. This characteristic is crucial in understanding the safety and handling of flammable liquids since it helps determine the conditions under which a liquid can become hazardous.

The other choices relate to different properties: while the boiling point is the temperature at which a liquid turns to vapor, it is not necessarily above the flash point. The flash point does not indicate that the liquid ignites instantly—it only signifies the temperature where vapors can start to be flammable. Furthermore, while the flash point can inform safe storage practices, it does not solely dictate safe temperatures for storage, as other factors must also be considered in ensuring safety.