Water extinguishers are only suitable for Class A fires consisting of paper, wood, straw, coal, rubber, solid plastics and soft furnishings. They are the simplest, most common, and least expensive type of extinguisher. Water extinguishers are the easiest to maintain variety and the least hazardous, since they only contain water. They cool the fire by soaking it and the materials with water, extinguishing the flames and absorbing heat from the burning objects, and are often found in shops, offices, retail premises, schools, hotels, warehouses and domestic premises.