Can you use water on a Class B fire?

Using water on a Class B fire is not advisable because Class B fires involve flammable liquids, gases, or greases, which can become more dangerous when water is introduced. Instead of extinguishing the flames, water can cause the flammable liquids to spread, potentially exacerbating the situation and leading to a larger fire.

Water is not effective against these types of fires because it can sit atop the burning liquid rather than extinguishing it. This action increases the likelihood of flare-ups and fire spreading to other areas. Therefore, the best action in response to a Class B fire is to use fire extinguishers specifically designed for such materials, such as foam or dry chemical extinguishers, which can effectively smother the flames without risking the spread of the fire.