A hairdryer is an electrical device used to dry and style hair. It uses an electric fan to blow air across a heating coil, as the air passes through the dryer it heats up. When the warm air reaches wet hair it helps evaporate the water. Hairdryers may be used with a variety of brushes and combs to achieve different hairstyles. All electrical appliances may be dangerous if misused. Hairdryers are particularly dangerous because they may accidentally drop into a sink or bathtub full of water. Therefore, special quality control precautions must be taken to reduce the chance of electrocution. Imaginative consumers have identified that hair dryers can be used for alternate functions such as removing chewing gum from hard surfaces and helping to dry nail polish.