Feature Story:

When it Comes to Electricity, Prepare Against Shocks!

For like many other health and safety hazards, electrical injuries are easily preventable. They fall into four general categories: electrocution, which is fatal; electric shock; burns; and injuries suffered from falls secondary to contact with electrical current.

An injury's severity is primarily a function of the magnitude of the current. In this case, current is measured in Amps, the pathway of the current through the body and the length of time the current flows through the body. How minute a quantity (Amps) of electric current can kill a person is illustrated in the table accompanying this article. It lists the potential health effects of standard household current (110V­220V) that may occur when electricity passes through the chest upon contact with a live wire.

Currents as tiny as 20 milliAmps (1/50th of an Amp) can be lethal. Most household circuits convey 15 to 20 Amps. For your protection, insulate wires and cords, turn off the power when working with electrical systems and maintain adequate distances from power lines that are not insulated. Ensure that electrical cords are in good condition. Obviously, appliance cords with cuts, cracks and broken insulation should not be used but taken instead to a qualified electrician for repair.

As for increasing resistance, electricity flows readily through materials that are good conductors--like metals and water. That's why electricians avoid wearing rings or metal watches while on the job. It is a common mistake to use a metal ladder when changing a light bulb, for instance, or performing other household tasks near electrical wires. For these chores, use a wood or fiberglass ladder.

When it comes to water, the simplest strategy is to ensure that you and your work area are dry. Dry intact skin, for example, has an average electrical resistance of 100,000 units of electrical resistance, or Ohms. If the skin is wet from perspiration, clothes, high humidity or other sources, the skin's resistance drops precipitously to 1,000 Ohms, which can change what would be an imperceptible or shocking experience with electricity into a deadly one. Wet conditions are common during electrocutions involving standard household electricity.

Common to all new U.S. construction is a safety device called a ground fault circuit interrupter, or GFCI. The GFCI trips when only 6 milliAmps of current leak from the system. Unlike conventional household breakers, GFCIs are designed to protect human beings from electricity. GFCI outlets are placed in kitchens, bathrooms and around swimming pools. In some countries, the entire house or a subset of the circuits may be hooked up to a GFCI breaker located in the main electrical distribution panel.

Before resetting a GFCI or any conventional breaker, first determine the reason it tripped. An appliance may run without any problems when plugged into a standard outlet. When plugged into a GFCI outlet, however, the appliance may shut off, signaling an electrical leak. This is potentially dangerous to the user--especially if the appliance is being operated around water. When this happens, stop using the appliance and get it repaired.

Local building codes in many countries prohibit installing electrical outlets in bathrooms. While this may seem inconvenient, particularly for Americans accustomed to electrical appliances in these areas, the practice should not be circumvented by installing non-GFCI outlets.

Finally, it is abnormal to receive a shock from an electrical appliance. Personnel overseas should contact their post occupational safety and health officer if this occurs. When isolation and increased resistance are practiced, electricity should not cause undue harm to your health.