The National Electric Code (NEC) is intended for use primarily by those who design, install, and inspect electrical installations. Therefore, requirements for electrical safety-related work practices and maintenance of the electrical system considered critical to safety are not found in the NEC. The NEC protects individuals from shock hazards under normal conditions. It is not designed to protect workers from abnormal conditions.

We need additional policies to protect from abnormal conditions. NFPA 70-E addresses these new policies to help protect workers from hazards associated with electrical work.


An average of one worker is electrocuted on the job every day. Electrocution is the forth leading cause of death in the workplace today. There are approximately 1000 electrocutions per year. OSHA citations are issued for 70% of all workplace electrocutions.

The University of San Diego performed a study about the causes of electrical injuries. The study found that only 3% of the accidents were caused by overhead power line work. Only 8% were caused by work on panel boards and transformers; 21% were the result of work on junction boxes below 8 feet and 68% above 8 feet.

Hazards of Electricity

The four basic hazards of electricity are shock, burn, arc, and fire ignition. Arc has only become a recognized hazard of electricity within the last few years. NFPA 70-E was the first standard to recognize and take steps to minimize arc hazards.

The incidence of fire ignition has dropped dramatically since the advent of the NEC and the acceptance of the installation requirements within the industry. The NEC does not concern itself primarily with the other three hazards of electricity.


Electrical shock is received when current passes through the body. The severity of the shock depends on three things: 1) the path of current through the body; 2) the amount of current flowing through the body; and 3) the length of time the body is in the circuit. Low voltage does not mean low hazard.

Electric shock can immediately affect the heart and breathing. It can also immediately cause muscle contraction, tingling sensations, pain, disorientation, and dizziness.

The long term affects of electrical shock can be memory loss, nervous disorders, chemical imbalances, and damage to the heart muscle.

Electrical shock with currents greater than 75 mA? can cause ventricular fibrillation (rapid, ineffective heartbeat). It could result in death in a few minutes unless a defibrillator is used. 75 mA is not much current. A small power drill uses 30 times as much current.

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