Water is not suitable for extinguishing fires involving 1.electrical equipment as water is a good conductor of electricity and there is more chance of getting electric shock 2.oil and petrol as if u pour water on this type of fire the oil will start floating on top and continues to burn
Water is not used to extinguish fire caused by electrical circuits because it would aggravate tha situation. While we can also not use it to extinguish fire caused by petroleum products and oils as they are lighter than water and float on its surface. And if we try to put water on it, we would help it to spread.