On which type of fire is it safe to use water?

Using water on fires requires careful consideration of the type of fire involved. In this case, the correct answer is that it is not safe to use water on any of the listed types of fires.

For electrical fires, water is a poor choice because it conducts electricity; using water can lead to electrical shock or worsen the fire. Gasoline fires also pose a significant hazard when water is introduced, as water can spread the flammable liquid, potentially causing a larger fire. Tire fires are particularly dangerous because they burn at extremely high temperatures and produce toxic smoke; adding water can be ineffective and counterproductive, as tires are made from rubber that does not easily extinguish.

Hence, the correct understanding is that for all the mentioned fire types, using water may exacerbate the situation rather than safely extinguishing the flames. This emphasizes the importance of recognizing the nature of the materials involved in a fire to ensure the use of appropriate extinguishing methods.