Sign warning of possible electric shock hazard

An electric shock can occur upon contact of a human's body with any source of voltage high enough to cause sufficient current flow through the muscles or hair. The minimum current a human can feel is thought to be about 1 milliampere (mA). The current may cause tissue damage or fibrillation if it is sufficiently high. A fatal electric shock is referred to as electrocution. Sign warning of electric shock hazard. ... Sign warning of electric shock hazard. ... International safety symbol Caution, risk of electric shock (ISO 3864), colloquially known as high voltage symbol. ... Look up current in Wiktionary, the free dictionary. ... For other uses, see Ampere (disambiguation). ... Fibrillation is the rapid, irregular, and unsynchronized contraction of the muscle fibers of the heart. ...

Shock effects

Psychological

The perception of electric shock can be different depending on the voltage, duration, current, path taken, frequency, etc. Current entering the hand has a threshold of perception of about 5 to 10 mA (milliampere) for DC and about 1 to 10 mA for AC at 60 Hz. Shock perception declines with increasing frequency, ultimately disappearing at frequencies above 15-20 kHz.

Burns

Heating due to resistance can cause extensive and deep burns. Voltage levels of (> 500 to 1000 V) shocks tend to cause internal burns due to the large energy (which is proportional to the duration multiplied by the square of the voltage) available from the source. Damage due to current is through tissue heating. In some cases 16 volts might be fatal to a human being when the electricity passes through organs such as the heart.

Ventricular fibrillation

A low-voltage (110 to 220 V), 50 or 60-Hz AC current travelling through the chest for a fraction of a second may induce ventricular fibrillation at currents as low as 60mA. With DC, 300 to 500 mA is required. If the current has a direct pathway to the heart (e.g., via a cardiac catheter or other kind of electrode), a much lower current of less than 1 mA, (AC or DC) can cause fibrillation. Fibrillations are usually lethal because all the heart muscle cells move independently. Above 200mA, muscle contractions are so strong that the heart muscles cannot move at all. Ventricular fibrillation (V-fib or VF) is a cardiac condition which consists of a lack of coordination of the contraction of the muscle tissue of the large chambers of the heart that eventually leads to the heart stopping altogether. ... For other uses, see Electrode (disambiguation). ...

Neurological effects

Current can cause interference with nervous control, especially over the heart and lungs. Repeated or severe electric shock which does not lead to death has been shown to cause neuropathy. Neuropathy is usually short for peripheral neuropathy, meaning a disease of the peripheral nervous system. ...

When the current path is through the head, it appears that, with sufficient current, loss of consciousness almost always occurs swiftly. (This is borne out by some limited self-experimentation by early designers of the electric chair and by research from the field of animal husbandry, where electric stunning has been extensively studied) [2]. The electric chair is an execution method in which the person being put to death is strapped to a chair and electrocuted through electrodes placed on the body. ... Shepherd with his sheep in Făgăraş Mountains, Romania. ...

Arc-flash hazards

Over 80% of all injuries and fatalities caused by electrical incidents are not caused by electric shock, but by the intense heat, light, and pressure wave (blast) caused by electrical faults.^{[citation needed]} The arc-flash in an electrical fault produces the same type of light radiation from which electric welders protect themselves using face shields with dark glass, heavy leather gloves, and full-coverage clothing. The heat produced may cause severe burns, especially on unprotected flesh. The blast produced by vaporizing metallic components can break bones and irreparably damage internal organs. The degree of hazard present at a particular location can be determined by a detailed analysis of the electrical system, and appropriate protection worn if the electrical work must be performed with the electricity on. Tree limbs cause a short circuit during a storm A short circuit (sometimes abbreviated to short or s/c) allows a charge to flow along a different path from the one intended. ... For other uses, see Radiation (disambiguation). ...

Issues affecting lethality

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. From a mains circuit the damage is more likely to be internal, leading to cardiac arrest. For other uses, see Frequency (disambiguation). ...

The comparison between the dangers of alternating current and direct current has been a subject of debate ever since the War of Currents in the 1880s. DC tends to cause continuous muscular contractions that make the victim hold on to a live conductor, thereby increasing the risk of deep tissue burns. On the other hand, mains-frequency AC tends to interfere more with the heart's electrical pacemaker, leading to an increased risk of fibrillation. AC at higher frequencies holds a different mixture of hazards, such as RF burns and the possibility of tissue damage with no immediate sensation of pain. Generally, higher frequency AC current tends to run along the skin rather than penetrating and touching vital organs such as the heart. While there will be severe burn damage at higher voltages, it is normally not fatal. City lights viewed in a motion blurred exposure. ... Direct current (DC or continuous current) is the continuous flow of electricity through a conductor such as a wire from high to low potential. ... // In the War of Currents era (sometimes, War of the Currents or Battle of Currents) in the late 1880s, George Westinghouse and Thomas Edison became adversaries due to Edisons promotion of direct current (DC) for electric power distribution over the alternating current (AC) advocated by Westinghouse and Nikola Tesla. ... Fibrillation is the rapid, irregular, and unsynchronized contraction of the muscle fibers of the heart. ... The heart and lungs, from an older edition of Grays Anatomy. ...

It is sometimes suggested that human lethality is most common with alternating current at 100-250 volts, however death has occurred from supplies as low as 32 volts and supplies at over 250 volts frequently cause fatalities. City lights viewed in a motion blurred exposure. ...

Electrical discharge from lightning tends to travel over the surface of the body causing burns and may cause respiratory arrest. Respiratory arrest is the cessation of the normal tidal flow of the lungs due to paralysis of the diaphragm, collapse of the lung or any number of respiratory failures. ...

Lethality of a shock

The voltage necessary for electrocution depends on the current flowing through the body and the duration of the current flow. Using Ohm's law, Voltage = Current x Resistance, we see that the current drawn depends on the resistance of the body. The resistance of our skin varies from person to person and fluctuates between different times of day. In general, dry skin isn't a very good conductor having a resistance of around 10,000 Ω, while skin dampened by tap water or sweat has a resistance of around 1,000 Ω. A voltage source, V, drives an electric current, I , through resistor, R, the three quantities obeying Ohms law: V = IR Ohms law states that, in an electrical circuit, the current passing through a conductor between two points is proportional to the potential difference (i. ...

The capability of a conducting material to carry a current depends on its cross section, which is why males typically have a higher lethal current than females (10 amperes vs 9 amperes) due to a larger amount of tissue. However, death can occur from currents as low as 0.1 to 0.3 amps.

Using Ohm's law, we may derive the voltages lethal to the human body. This is given in the following table: ^[1]

Point of entry

• Macroshock: Current flowing across intact skin and through the body. Current traveling from arm to arm, or between an arm and a foot, is likely to traverse the heart, and so is much more dangerous than current traveling between a leg and the ground.
• Microshock: Direct current path to the heart tissue

Microshock is a risk in patients with intracardiac conductors, such as external pacemaker electrodes or saline filled catheters, within the heart. ...

Avoiding danger of shock

It is strongly recommended that people should not work on exposed live conductors if at all possible. If this is not possible then insulated gloves and tools should be used. If both hands make contact with surfaces or objects at different voltages, current can flow through the body from one hand to the other. This can lead the current to pass through the heart. Similarly, if the current passes from one hand to the feet, significant current will probably pass through the heart. An alternative to using insulated tools is to isolate the operator from ground, so that there is no conductive path from the live conductor, through the operator's body, to ground. This method is used for working on live high-voltage overhead power lines. ^[2] Power line redirects here. ...

It is possible to have a voltage potential between neutral wires and ground in the event of an improperly wired (disconnected) neutral, or if it is part of certain obsolete (and now illegal [citation required]) switch circuits. The electrical appliance or lighting may provide some voltage drop, but not nearly enough to avoid a shock. "Live" neutral wires should be treated with the same respect as live wires. Also, the neutral wire must be insulated to the same degree as the live wire to avoid a short circuit. Not to be confused with lightning. ... This article or section is in need of attention from an expert on the subject. ... For alternate meanings see Short circuit (disambiguation) A short circuit (sometimes known as simply a short) is a fault whereby electricity moves through a circuit in an unintended path, usually due to a connection forming where none was expected. ...

Electrical codes in many parts of the world call for installing a residual-current device (RCD or GFCI, earth fault circuit interrupter) on electrical circuits thought to pose a particular hazard to reduce the risk of electrocution. In the USA, for example, a new or remodeled residential dwelling must have them installed in all kitchens, bathrooms, laundry rooms, garages, and any other room with an unfinished concrete floor such as a workshop. These devices work by detecting an imbalance between the live and neutral wires. In other words, if more current is passing through the live wire than is returning though its neutral wire, it assumes something is wrong and breaks the circuit in a fraction of a second. There is some concern that it might not be fast enough for infants and small children in rare instances. A residual current device (RCD) A residual current device (RCD), or residual current circuit breaker (RCCB), is an electrical wiring device that disconnects a circuit whenever it detects that the flow of current is not balanced between the phase (hot) conductor and the neutral conductor. ... This article is about the construction material. ...

The plumbing system in a home or other building has traditionally used metal pipes and thus been connected to ground through the pipes. This is no longer always true because of the extensive use of plastic PVC piping in recent years, but a plastic system cannot be relied upon for safety purposes. Contrary to popular belief, pure water is not a good conductor of electricity. However, most water is not pure and contains enough dissolved particles (salts) to greatly enhance its conductivity. When the human skin becomes wet, it allows much more current to flow than the dry human body would. Thus, being in the bath or shower will not only ground oneself to return path of the power mains, but lower the body's resistance as well. Under these circumstances, touching any metal switch or appliance that is connected to the power mains could result in electrocution. While such an appliance is not supposed to be live on its outer metal switch or frame, it may have become so if a defective live bare wire is accidentally touching it (either directly or indirectly via internal metal parts). It is for this reason that mains electrical sockets are prohibited in bathrooms in the UK. However, widespread use of plastic cases for everyday appliances (which won't conduct electricity), grounding of these appliances, and mandatory installation of Residual Current Devices (R.C.D.s) have greatly reduced this type of electrocution over the past few decades. A plumber wrench for working on pipes and fittings A complex arrangement of rigid steel piping, stop valves regulate flow to various parts of the building. ... PVC may refer to the following: Polyvinyl chloride, a plastic Premature ventricular contraction, irregular heartbeat Permanent virtual circuit, a term used in telecommunications and computer networks Param Vir Chakra, Indias highest military honor. ... Physical Features of the Human Body The human body is the entire physical structure of a human organism. ... For other uses, see Plastic (disambiguation). ...

A properly earthed appliance eliminates the electric shock potential by causing a short circuit if any portion of the metal frame (chassis) is accidentally touching the live wire. This will cause the circuit breaker to turn off or the fuse to blow resulting in a power outage in that area of the home or building. Often there will be a large "bang" and possibly smoke which could easily scare anyone nearby. However, this is still much safer than risking electric shock, as the chance of an out-of-control fire is remote. Many people in this situation have nevertheless called the fire department as a precaution. For alternate meanings see Short circuit (disambiguation) A short circuit (sometimes known as simply a short) is a fault whereby electricity moves through a circuit in an unintended path, usually due to a connection forming where none was expected. ... Look up Chassis in Wiktionary, the free dictionary. ... A 2 pole miniature circuit breaker A circuit breaker is an automatically-operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. ... Look up fuse in Wiktionary, the free dictionary. ... Firefighter with an axe A firefighter, sometimes still called a fireman though women have increasingly joined firefighting units, is a person who is trained and equipped to put out fires, rescue people and in some areas provide emergency medical services. ...

Where live circuits must be frequently worked on (e.g. television repair), an isolation transformer is used. Unlike ordinary transformers which raise or lower voltage, the coil windings of an isolation transformer are at a 1:1 ratio which keeps the voltage unchanged. The purpose is to isolate the neutral wire so that it has no connection to ground. Thus, if a technician accidentally touched the live chassis and earth at the same time, nothing would happen. An isolation transformer is a transformer, often with symmetrical windings, which is used to decouple two circuits. ...

Neither earth fault circuit interrupters (RCD/GFCI) nor isolation transformers can prevent electrocution between the live and neutral wires. This is the same path used by functional electrical appliances, so protection is not possible. However, most accidental electrocutions, especially those not involving electrical work and repair, are via earth -- not the neutral wire.

First Aid

In helping a victim of an electric shock, the first thing you must do is disconnect the power supply, if it is safe to do and will not take long to find; touching the power source may put you in danger. If the victim is in contact with something portable such as a hair dryer, attempt to move it away using a non-conductive object such as a wooden broom. Time is precious and knocking the victim from the source can prove an effective way to speed the process. Do not attempt to touch the affected person until they are free and clear of the supplied power. Don’t even touch the victim until you are sure the power supply is turned off. Be especially careful in wet areas, such as bathrooms, since most water will conduct electricity and electrocuting yourself is also possible.

People "hung up" in a live current flow may think they are calling out for help but most likely no sound will be heard from them. When the muscles contract under household current, the person affected will appear in lock-up state, unable to move or react to you. When using a wooden object, swiftly knock the person free without severely trying to injure them, but strong enough to free, and land them clear of the source. The source may also be lifted or removed, if possible, with the same wooden item. This is not recommended on voltages that exceed 500 volts. Most electrocutions happen from house current at home. Do not attempt without rubber or some form of insulated sole shoes; bare or socked feet will allow the current to flow to ground through your body as well.

First aid instructions

1. Check if you are alone. If there are other people around, instruct them to call an ambulance right away.
2. Check for a response and breathing. If the area is safe for you to be in, and you have removed the object or have cut off its power supply, yell to the person to see if they are conscious. At this stage, do not touch the victim. Check once again to see if the area is safe. If you are satisfied that it is safe, start resuscitating the victim. If you have no first aid knowledge, skip to the next step if someone has not already done it for you.
3. Call emergency services for an ambulance.
4. If the breathing and pulse are steady, attend to injuries. Cool the burns and cover with dressings that won’t stick. Never put ointments or oils onto burns. If the victim has fallen from a height, only move them if there is chance of further danger (such as falling objects). Try not to move them unnecessarily in case of spinal injuries or causing them excess pain, unless you are satisfied that moving them is necessary to prevent further dangers.
5. Talk calmly and reassuringly to the conscious victim until the ambulance arrives.

Many countries public telephone networks have a single emergency telephone number, sometimes known as the universal emergency telephone number or occasionally the emergency services number, that allows a caller to contact local emergency services for assistance. ... Consciousness is a quality of the mind generally regarded to comprise qualities such as subjectivity, self-awareness, sentience, sapience, and the ability to perceive the relationship between oneself and ones environment. ...

Electrocution statistics

There were 550 electrocutions in the US in 1993, which translates to 2.1 deaths per million inhabitants. At that time, the incidence of electrocutions was decreasing. ^[3] Electrocutions in the workplace make up the majority of these fatalities. From 1980-1992, an average of 411 workers were killed each year by electrocution. ^[4]

Deliberate uses

Electroconvulsive Therapy

Electric shock is also used as a medical therapy, under carefully controlled conditions:

• Electroconvulsive therapy or ECT In a psychiatric therapy for mental illness. The objective of the therapy is to induce a seizure for theraputic effect. There is no sensation of shock because the patient is anesthetized. The therapy was originally conceived of after it was observed that depressed patients who also suffered from epilepsy experienced some remission after a spontaneous seizure.^{[citation needed]} The first attempts at deliberately inducing seizure as therapy used not electricity but chemicals; however electricity provided finer control for delivering the minimum stimulus needed. Ideally some other method of inducing seizure would be used, as the electricity may be associated with some of the negative side effects of ECT including amnesia.

• As a treatment for fibrillation or irregular heart rhythms: see defibrillator and cardioversion.

• As a method of pain relief: see Transcutaneous Electrical Nerve Stimulator (more commonly referred to as a TENS unit).

• As an aversive punishment for conditioning of mentally handicapped patients with severe behavioral issues. This method is highly controversial and is employed at only one institution in the United States, the Judge Rotenberg Educational Center. The institute also uses electric shock punishments on non-handicapped children with behavioral problems. Whether this constitutes legitimate medical treatment versus abusive discipline is the subject of ongoing litigation.

Electroconvulsive therapy (ECT), also known as electroshock, is a controversial psychiatric treatment in which seizures are induced with electricity for therapeutic effect. ... A mental illness or mental disorder refers to one of many mental health conditions characterized by distress, impaired cognitive functioning, atypical behavior, emotional dysregulation, and/or maladaptive behavior. ... This article or section does not adequately cite its references or sources. ... Through electricity or drug therapy, cardioversion converts heart arrhythmias to normal rhythms. ... Pain therapy is treatment given to patients experiencing chronic or acute pain. ... “TENS” redirects here. ... The Judge Rotenberg Educational Center (JRC, formerly known as the Behavior Research Institute) is a special needs school serving children and young adults with autistic-like behaviors, conduct, emotional, and/or psychiatric problems located in Canton, Massachusetts. ...

Torture

Main article: torture

Electric shocks have been used as a method of torture, since the received voltage and amperage can be controlled with precision and used to cause pain while avoiding obvious evidence on the victim's body. Such torture usually uses electrodes attached to parts of the victim's body. The genitalia are amongst the most painful, and at the same time humiliating. Nipples and the tongue are also frequent sites. Another frequent method of electrical torture is stunning with an electroshock gun such as a cattle prod or a taser (provided a sufficiently high voltage and non-lethal current is used in the former case). For other uses, see Torture (disambiguation). ... For other uses, see Torture (disambiguation). ... An electroshock gun, also referred to as a stun gun, is a weapon used for subduing a person by firing something which administers electric shock, disrupting superficial muscle functions. ... // A cattle prod, also called a stock prod, is a handheld device commonly used to make cattle or other livestock move by striking or poking them, or (in the case of a hotshot) through a (relatively) high voltage, low current electric shock. ... An electroshock gun, also referred to as a stun gun, is a weapon used for subduing a person by firing something which administers electric shock, disrupting superficial muscle functions. ... Josephson junction array chip developed by NIST as a standard volt. ... Electric current is the flow (movement) of electric charge. ...

The Nazis are known to have used electrical torture during World War II^{[citation needed]}. An extensive fictional depiction of such torture is included in the 1966 book The Secret of Santa Vittoria by Robert Crichton. During the Vietnam War, electric shock torture is said to have been used by both sides. A scene of electrical torture in the American Deep South is included in the 1980 Robert Redford film Brubaker. Amnesty International published an official statement that Russian military forces in Chechnya tortured local women with electric shocks by connecting electric wires to their bra straps ^[5]. An example in popular modern culture is the electric torture of Riggs in Lethal Weapon. National Socialism redirects here. ... Combatants Allied powers: China France Great Britain Soviet Union United States and others Axis powers: Germany Italy Japan and others Commanders Chiang Kai-shek Charles de Gaulle Winston Churchill Joseph Stalin Franklin Roosevelt Adolf Hitler Benito Mussolini Hideki Tōjō Casualties Military dead: 17,000,000 Civilian dead: 33,000... Robert Crichton (born January 29, 1925; died March 23, 1993) was an American novelist. ... Combatants Republic of Vietnam United States Republic of Korea Thailand Australia New Zealand The Philippines National Front for the Liberation of South Vietnam Democratic Republic of Vietnam People’s Republic of China Democratic Peoples Republic of Korea Strength US 1,000,000 South Korea 300,000 Australia 48,000... For other uses, see Deep South (disambiguation). ... Robert Redford (born Charles Robert Redford, Jr. ... Brubaker is an American 1980 film about a prison in distress. ... Wikimedia Commons has media related to: Amnesty international Amnesty International (commonly known as Amnesty or AI) is an international non-governmental organization which defines its mission as to undertake research and action focused on preventing and ending grave abuses of the rights to physical and mental integrity, freedom of conscience... The Chechen Republic (IPA: ; Russian: , Chechenskaya Respublika; Chechen: , Noxçiyn Respublika), or, informally, Chechnya (; Russian: ; Chechen: , Noxçiyçö), sometimes referred to as Ichkeria, Chechnia, Chechenia or Noxçiyn, is a federal subject of Russia. ... Martin Riggs (born 1950) is a fictional police officer from the Lethal Weapon franchise. ... This article does not cite any references or sources. ...

Advocates for the mentally ill and some psychiatrists such as Thomas Szasz have asserted that electroconvulsive therapy is torture when used without bona fide medical benefit against recalcitrant or non-responsive patients. See above for ECT as medical therapy. These same arguments and oppositions apply to the use of extremely painful shocks as punishment for behavior modification, a practice that is openly used only at the Judge Rotenberg Institute. A mental illness or mental disorder refers to one of many mental health conditions characterized by distress, impaired cognitive functioning, atypical behavior, emotional dysregulation, and/or maladaptive behavior. ... For other uses, see Psychiatrist (disambiguation). ... Szasz redirects here. ... Sign warning of possible electric shock hazard An electric shock can occur upon contact of a human or animal body with any source of voltage high enough to cause sufficient current flow through the muscles or nerves. ...

Capital punishment

Main article: Electric chair

Electric shock delivered by an electric chair is sometimes used as a means of capital punishment, although its use has become rare in recent times. Although the chair was at one time considered a more humane and modern execution method than hanging, shooting, or decapitation, it is now being replaced for the same reasons by lethal injection. Modern reportage has revealed that it sometimes takes several shocks to be effective, and that the condemned person may actually catch fire before the process is complete.^{[citation needed]} The electric chair is an execution method in which the person being put to death is strapped to a chair and electrocuted through electrodes placed on the body. ... The electric chair is an execution method in which the person being put to death is strapped to a chair and electrocuted through electrodes placed on the body. ... Capital punishment, or the death penalty, is the execution of a convicted criminal by the state as punishment for crimes known as capital crimes or capital offences. ... This article is about the execution and euthanasia method. ...

Throughout the world, execution via electric shock has widely been regarded as inhumane.^{[citation needed]} Other than the United States, only the Philippines used this method for a few years. It remains a legal means of execution in some states of the USA.^[6] It is reportedly one of the most grisly forms of modern execution to witness, with smoke or actual flame visible, coming from the prisoner's garments or cap.

Games and pranks

Electric shock is sometimes used as a punishment in novelty games such as Lightning Reaction, Shocking Roulette, Shocking Liar, Laser Shock Guns, and Shocking Tanks. In addition to these games, there are some prank toys such as fake pens, chocolate candy, card holders or cigarette lighter which give out a mild shock. The Lightning Reaction Extreme Game Lightning Reaction is a game for two to four players. ... Shocking Tanks is a novelty game involving remote control toy tanks. ... A metal naphtha lighter A lighter is a device used to create fire with the intent to ignite another substance such as a cigarette, smoking pipe, or charcoal in a grill. ...

See also

• Static electricity
• Electromagnetism
• Transcutaneous Electrical Nerve Stimulator

Static electricity is a class of phenomena involving the net charge present on an object; typically referring to charged object with voltages of sufficient magnitude to produce visible attraction, repulsion, and sparks. ... Electromagnetism is the physics of the electromagnetic field: a field which exerts a force on particles that possess the property of electric charge, and is in turn affected by the presence and motion of those particles. ... “TENS” redirects here. ...

References

Arizona State University (ASU) is a public research institution of higher education and research with campuses located in the Phoenix Metropolitan Area. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 165th day of the year (166th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 247th day of the year (248th in leap years) in the Gregorian calendar. ... Wikimedia Commons has media related to: Amnesty international Amnesty International (commonly known as Amnesty or AI) is an international non-governmental organization which defines its mission as to undertake research and action focused on preventing and ending grave abuses of the rights to physical and mental integrity, freedom of conscience...

External links

• National Institute for Occupation Safety & Health: Worker Deaths by Electrocution a CDC study.
• Physiological effects of electricity
• Shock current path
• Electrical injury (Merck Manual)
• Electric Shock Hazards (Hyperphysics)
• Question: Why Does Mixing Water and Electricity Cause Electric Shock?
• Electric Shock - a more technical perspective
• Construction Safety Association of Ontario: Electrocution ... article with case studies
• Protection against electric shocks - Physiological effects and protection rules