Electrocution

An electric shock, or electrocution, may occur upon contact of a human with electricity. Current electrical codes in many parts of the world call for installing a residual-current device (RCD or GFCI, ground fault circuit interrupter) on electrical circuits thought to pose a particular hazard to reduce the risk of electrocution.

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1 Description 2 Working With Electricity 3 Theft of Hardware 4 Electrocution Prevention 4.1 Safe Work Practices 4.2 CPR and ACLS Procedures 5 Ogrish Content

Description

An electric shock is often painful and can even be lethal, but the level of voltage is not a direct guide to harmfulness, despite the popularity of such a measure. Physiological effects are determined by voltage, current and duration. A high voltage and a high current together are lethal, but so are a lower voltage and current of extended duration. An example of the first would be a lightning strike and of the second would be contact with a live mains cable, but even a mains cable is carrying many times a minimum lethal shock.
Electrical discharge from lightning tends to travel over the surface of the body and causes respiratory arrest. From a mains circuit the damage is more likely to be internal, leading to cardiac arrest. With line currents above 2 milliamperes there can be a muscular spasm which causes the affected person to grip and be unable to release from the current source. It is believed that human lethality is most common with AC current at 100-250 volts, as lower voltages can fail to overcome body resistance while with higher voltages the victim's muscular contractions are often severe enough to cause them to recoil (although there will be considerable burn damage). Damage due to current is through tissue heating and interference with nervous control, especially over the heart. Fibrillation can be induced (and removed) by 100 mA, although, oddly, with higher currents (200 mA and above) contractions in muscles around the heart can actually prevent the heart from fibrillating. Fibrillations are usually lethal because all the heart muscle cells move independently, tearing the tissue and destroying the heart beyond recovery. But at 200mA, the contractions are so strong that the heart muscles cannot move at all. Tissue heating due to resistance can cause extensive and deep burns. Other issues affecting lethality are frequency, which is an issue in causing cardiac arrest or muscular spasms, and pathway - if the current passes through the chest or head there is an increased chance of death.
Depending on the circumstances, a human can survive 35 kV without great harm while 50 V can kill. The usual voltage threshold of dry skin is 50 volts DC. The above information would appear to suggest that the requirements to distribute electrical current to domestic users have resulted in a combination that is quite deadly. In parts of America and a few countries like Japan, the power is distributed at 110-120 V AC to the end users. In Europe and most other countries, it is distributed at 220-240 volts.

Working With Electricity

Worker electrocuted in India

Working with electricity can be dangerous. Engineers, electricians, and other professionals work with electricity directly, including working on overhead lines, cable harnesses, and circuit assemblies. Others, such as office workers and salespeople work with electricity indirectly and may also be exposed to electrical hazards.
Many deaths and injuries arise from:

• Use of poorly maintained electrical equipment

• Work near overhead power lines

• Contact with underground power cables during excavation work

• Work on or near 230 volt domestic electricity supplies

• Use of unsuitable electrical equipment in explosive areas such as car paint spraying booths

It is strongly recommended that people working with exposed parts of electrical machines should work with only one of their hands. The best way to do this is to keep your left hand in your pocket. This is because if both hands make contact with the wrong surfaces, the current flows through the body from one hand to the other. This can lead the current to pass through the heart. Conversely, if the current passes from one hand to the feet, little current will probably pass through the heart.

Theft of Hardware

An electrocuted thief

Utilities that supply power are subject to theft of service and theft of hardware used to provide service. Individuals who try to steal from a power utility risk electrocution. We conducted a retrospective study of all individuals examined by the Jefferson County Coroner Medical Examiner Office from January 1981 through December 2001 and found that 8 individuals died trying to steal from a power utility. All decedents were men, with an average age of 33 years. Seven decedents were stealing copper, and 1 was stealing electricity. Only 1 decedent survived long enough to be admitted to a hospital. Five decedents were intoxicated, 3 with ethanol, 1 with cocaine, and 1 with both cocaine and ethanol. Seven decedents sustained electrical burns in keeping with the high voltage to which they were subjected. The unburned decedent died of laceration of the aorta at its origin from the heart, an injury sustained when the decedent fell from the power pole. All 8 decedents attempted their theft during daylight. Items found in the decedent's pockets, the presence of a ladder nearby, or the presence of electrical tools around the body may help to establish the attempted act of theft.

Electrocution Prevention

For staff and volunteers working on a building repair program, there may be a risk of electrocution. This can happen when using portable metal or conductive ladders near energized overhead power lines, when using power tools, or when work is being completed on the structure’s electrical system.
According to National Institute for Occupational Health and Safety (NIOSH), electrocution victims can be revived if immediate cardiopulmonary resuscitation (CPR) or defibrillation is provided. While immediate defibrillation would be ideal, CPR given within approximately 4 minutes of the electrocution, followed by advanced cardiac life support (ACLS) measures within approximately 8 minutes, can be lifesaving. Nonprofits should ensure that a number of its staff and volunteers are trained in CPR to help save the lives of workers who contact electrical energy. Nonprofits can also limit the probability that any of its staff or volunteers are electrocuted through prevention, safe work practices, and training in CPR and ACLS procedures.
Prevention must be the primary goal of any nonprofit’s workplace safety program. However, since contact with electrical energy occurs even in facilities that promote safety, safety programs should provide for an appropriate emergency medical response.

Safe Work Practices

No one who works with electric energy should work alone; a “buddy system” should be established. It may be advisable to have both members of the buddy system trained in CPR, as one cannot predict which one will contact electrical energy. Every individual who works with or around electrical energy should be familiar with emergency procedures. This should include knowing how to de-energize the electrical system before rescuing or beginning resuscitation on a worker who remains in contact with an electrical energy source. All workers exposed to electrical hazards should be made aware that even “low” voltage circuits can be fatal, and that prompt emergency medical care can be lifesaving.

CPR and ACLS Procedures

Cardiopulmonary Resuscitation (CPR) and first aid should be immediately available at every nonprofit’s work site. This capability is necessary to provide prompt (within 4 minutes) care for the victims of cardiac or respiratory arrest, from any cause. Nonprofit employers may contact the local office of the American Heart Association, the American Red Cross, or similar groups or agencies, to set up a course for employees and volunteers. Provisions should be worked out at each work site to provide ACLS within 8 minutes (if possible), usually by calling an ambulance staffed by paramedics. Signs on or near phones should give the correct emergency number for the area, and workers should be educated regarding the information to give when the call is made. For large facilities, a prearranged place should be established for the nonprofit’s workers to meet paramedics in an emergency.