Ensure that cords from electric tools do not present a tripping hazard. If approved, they do not require grounding under the National Electrical Code. Although this design method reduces the risk of grounding deficiencies, a shock hazard can still exist. Such tools are often used in areas where there is considerable moisture or wetness. Although the user is insulated from the electrical wiring components, water can still enter the tool's housing.
Ordinary water is a conductor of electricity.
If water contacts the energized parts inside the housing, it provides a path to the outside, bypassing the double insulation . When a person holding a hand tool under these conditions contacts another conductive surface, an electric shock occurs. If a power tool, even when double-insulated, is dropped into water, the employee should resist the initial human response to grab for the equipment without first disconnecting the power source. Another potential hazard is using extension cords with portable tools. In construction, these cords suffer a lot of wear and tear.