Toolbox Meeting 3 -- ELECTRICAL SHOCK

Electrical shock kills and injures hundreds of workers each year. Most accidents happen because people don't look, don't think, or just don't understand the shocking power of electricity. Voltage, current and resistance are the basic terms used when talking about electricity.

Voltage is the force that causes the current to flow. Current (amperage) refers to the amount of electricity that is flowing. Resistance denotes the restrictions that try to slow down or stop the flow.

Electrical shock can only occur when a part of the body completes a circuit between a conductor and another conductor or a grounding source.

Death or injury is not caused by the voltage; the damage is done by the amount of current that flows through the body when the contact is made. Of course, the higher the voltage, the greater the amount of current. Some people have survived shocks of several thousand volts, while others have been killed by voltages as low as 12. Less than one ampere can kill.

The dry, outer skin of the human body offers extremely high resistance to electrical flow. This resistance is reduced to almost zero when the skin is wet, especially if the skin is wet because of perspiration.

Electricity and proper grounding work together for safety. A ground is a conducting connection between an electrical circuit or piece of equipment and the earth, or to some conducting body that serves in place of the earth.

If your body is sweaty or damp, an oversensitive ground within it is created, which easily causes electrical shock. One way to keep the body's resistance high is to keep it dry, particularly the hands and feet, which might make the contacts and be instrumental in completing the circuit. Take care to be safely isolated (i.e. rubber mats, isolated tools, EH rated shoes).

Effects of electrical shock depend mainly on the total amount of current flow and the path of the current through the victim's body. To prevent electrical shock, which can cause several types of injuries, make sure that your body cannot become part of the electrical flow and the path of the current.

An important phase of electrical safety is knowing how to help an electrical shock victim. First, stop the current flowing from the circuit through the victim's body, if it hasn't already been done. Often, particularly in the cases of low-voltage shock, victims are unable to pull away from the source of current. If the victim is still in contact with the current, disconnect or de-energize the circuit, if possible. If this cannot be accomplished, obtain a nonconductive item, such as dry clothing, dry rope or a dry stick, and remove the victim from the source of the current.

Then call or send for help. Next, check to see if the victim's heart or breathing has stopped. Give the required first aid until professional help arrives.

We can reduce the risk of accidents in our workplace by keeping in mind these guidelines:
• Always use Ground Fault Circuit Interrupters (GFCIs) even when using double insulated tools.
• Never use water to put out an electrical fire; water can cause a fatal shock. Use a Class C-rated fire extinguisher for electrical fires; shut off the source of power as quickly as possible.
• Inspect the area you're working in for electrical hazards.
• Treat all circuits as live until tested
• Remove jewelry and other metal objects when working on electrical circuits.
• Don't overload circuits.
• Keep electrical equipment away from water and dampness.
• Check electrical cords before, during and after each use for fraying and other signs of wear and defects.
• Be sure to lockout and tagout switches when working on equipment.
Remember, electricity can be an ally or an enemy. Treat it with respect and it will provide the service you expect.

For more information read section 5 - Electrical Safety - in the Elevator Industry Field Employees' Safety Handbook