What happens to the spread of grease fires if water is thrown on them?

Water is ineffective and dangerous when used on grease fires due to its unique properties. When water is thrown onto a grease fire, it does not effectively extinguish the flames. Instead, the water can cause the burning grease to splatter and spread, which can intensify the fire and lead to a larger fire hazard. This occurs because water is denser than oil; when the water hits the burning grease, the rapid vaporization creates steam, which can propel flaming grease away from the original source, causing the fire to spread. Consequently, the best approach for grease fires is to use a fire extinguisher specifically designed for such fires or to cover the flames with a metal lid or cookie sheet to suffocate the fire.