Any material that electricity cannot flow through is called an insulator. The outside of an electric cord is covered with insulation to prevent the electric current from escaping. Some examples of insulators are plastic, glass, and rubber. Electric wires are usually covered in plastic or rubber.

Water is a good conductor. It can be dangerous for a person to use an electrical appliance near water. If the wire is not perfectly insulated, electricity can escape out of the wire. The electricity can then travel through the water and shock a person touching the water. A human body is also a good conductor, because the human body is made up mostly of water! Be very careful when operating electrical appliances near water, and protect yourself by wearing shoes with plastic or rubber soles (insulators) so your body doesn’t accidentally become a conductor of electricity.