At what temperature does a liquid's vapors ignite but not sustain combustion?

The correct choice refers to the flashpoint, which is the specific temperature at which the vapors of a liquid ignite when an ignition source is present. However, it is important to note that at this temperature, while the vapors can catch fire, they do not burn continuously without the presence of the ignition source; therefore, they don't sustain combustion on their own.

Understanding the flashpoint is crucial in hazardous material management, safety protocols, and fire prevention measures. The flashpoint helps determine how flammable a liquid is and is a key factor in creating safe handling and storage procedures, ensuring that materials are used in a way that minimizes risks of fire or explosion.

The other terms mentioned, such as boiling point and combustion point, refer to different properties of liquids. The boiling point is the temperature at which the liquid converts to vapor throughout the entire body of liquid, while the combustion point refers to the temperature where a substance will burn continuously without any external ignition source. Neither of these terms accurately describes the condition of igniting vapors without sustained combustion, which is why flashpoint is the correct answer.