Amperage vs. Voltage: The Dangers of Electrical Shock


Electricity is an essential part of modern life, powering our homes, workplaces, and devices. However, electricity also carries risks, especially the dangers of electric shock. Electrical shock occurs when a person comes into contact with an electrically energized surface. This disrupts the normal electrical rhythms in the body and can cause severe injuries or even death. Two key factors that determine the severity of an electrical shock are amperage and voltage. Understanding the difference between amperage and voltage is crucial to appreciate the hazards posed by electrical shocks. This article examines the distinction between amperage and voltage, how they contribute to electrical shock dangers, safety tips, and steps you can take to prevent electrical accidents.

Amperage and Electrical Shock

Amperage (or current) measures the flow rate of electrons through a conductor. It is expressed in amps or amperes. Higher amperage indicates a larger flow of current. Even a small amount of current flowing through the heart can lead to lethal disruption of the heart’s electrical rhythms, resulting in cardiac arrest. Human skin resistance can impede low amperage current, but higher ampere current can push through this barrier and reach the heart and muscles. As little as 100-200 milliamps (mA) of electrical current can cause human muscular contractions severe enough to impair breathing, leading to respiratory arrest. Any amperage over 200 mA is considered dangerous and can result in burns or electrocution.

Higher amperage also leads to more severe burns. Mild shocks may only cause tingling sensations, but amperage over 500 mA can result in deep tissue and internal organ burns. Any electrical current over 2 amps is almost always fatal. Here are some examples of the dangers posed by different amperages:

  • 10-20 mA: Perceptible shock, but typically not painful. However, still dangerous.
  • 50-100 mA: Painful shocks that can cause loss of muscular control.
  • 100-200 mA: Extremely painful and likely to cause respiratory or cardiac arrest.
  • 500-1000 mA: Severe burns and permanent organ damage.
  • 2000+ mA: Fatal shock.

Household electrical outlets in the United States deliver 15-20 amps, making a shock highly dangerous and potentially lethal. Higher amp appliances like large air conditioners can deliver even deadlier levels of current.

Voltage and Electrical Injuries

Voltage measures the “push” behind current, or electric potential difference. It is expressed in volts. Household voltage in the U.S. is 120 volts, lower than many other countries which use 220-240 volts. While amperage determines the amount of current flowing through your body, voltage influences the ability of the current to pass through skin and tissue resistance. Higher voltage gives a shock more “pushing power” to get current to flow through the skin and muscles despite their impedance. Low voltage may not be able to push current across skin resistance at all.

Higher voltage increases the hazards of electrical shocks. While skin resistance may stop a mild 24 volt shock, 120+ volts can more easily penetrate skin, especially if the skin is wet or the contact area is large. Electrical burns are also more severe with higher voltage. Here are some examples of the dangers posed by different voltages:

  • 24-50 volts: May be imperceptible. Not likely to cause injury except with wet skin or prolonged contact.
  • 120-220 volts: Common household current. Can cause respiratory arrest and severe burns with sufficient amperage and skin contact.
  • 600+ volts: Used in industrial supplies. Extremely dangerous, often fatal shocks.
  • 25,000+ volts: High voltage power lines and supplies. Always fatal if contacted.

High voltage paired with high amperage is an especially lethal combination, as the voltage “pushes” a large surge of current through the body. Even low voltages become dangerous when pushing high amperages.

Why Electrical Shock is So Dangerous

Electrical shocks pose severe hazards because of how electricity interacts with the human body. Our nervous system relies on delicate bioelectrical signals and processes that can be thrown into chaos by an external electrical current.

When an external electrical current passes through the body, it can interrupt the natural electrical rhythms in the heart, lungs, and other critical organs. The resulting chaos can cause:

  • Irregular heart rhythms, cardiac arrest
  • Respiratory paralysis or failure
  • Severe muscle contractions that may cause fractures or inability to let go of an electrified object
  • Damage to tissues, internal burns and organ injury
  • Neurological disruption, seizures, or death

The most common causes of death from electrical shocks are cardiac arrest and respiratory failure. Even if the shock victim survives, they may suffer severe burns, neurological damage, or disability from fractures or the loss of limbs if the current caused uncontrollable muscular contractions.

Children and the elderly are particularly vulnerable to electrical injury because of their smaller body mass and more fragile neurological and cardiovascular systems. Household electrical accidents are a leading cause of injury and death among young children.

Where Electrical Shock Hazards Exist

Electrical dangers lurk almost everywhere in our electrified modern world. Key risks include:

  • Faulty electrical outlets, cords, and power strips: Damaged, loose, or corroded connections in outlets, cords, and power strips can expose live wires and current.
  • Appliances: Defective appliances or damaged cords can electrify the whole device. Even normally safe appliances can become dangerous if operated with wet hands or while standing in water.
  • Liquids: Anything that conducts electricity, like water or saliva, can become a path for current if contacting a live wire or appliance. Wet skin or clothing increases the risk.
  • Power lines: Overhead high voltage power lines pose extreme danger. Contacting downed power lines can result in lethal shocks.
  • Lightning: The massive electrical discharge of a lightning strike can instantly stop the heart or breathing.
  • Electrical wiring: Exposed, damaged, or overloaded building wiring can deliver dangerous shocks and cause fires. Aluminum wiring found in many older buildings is especially hazardous.

Proper precautions are essential around all these electrical hazards, especially when water or liquids are present. Even low voltage supplies can become lethal if enough amperage passes through the body.

Electrical Shock Safety Tips

You can protect yourself and your family from electrical shock hazards by following these common sense precautions:

  • Keep appliances and cords in good repair – Do not use any device or cord that appears damaged, frayed, or corroded. Unplug devices by gripping the plug, not the cord. Shut off power before changing lightbulbs or performing repairs near outlets.
  • Use ground fault circuit interrupters (GFCIs) – Install GFCIs on outlets near water sources like kitchens, bathrooms, and outdoor areas. A GFCI shuts off power at the first detection of any leakage current.
  • Keep appliances and outlets away from water – Never use electrical devices with wet hands or while standing in water. Install plastic safety covers on outlets near sinks or tubs.
  • Use caution around overhead lines – Keep ladders, pool skimmers, and other lengthy items far away from power lines. Never touch a downed power line. Call the utility company immediately if a power line is down.
  • Get outdoor outlets checked – Have a qualified electrician inspect all outdoor outlets, especially if not equipped with a GFCI.
  • Keep metallic items away from electricity – Never stick metal objects into outlets or appliances. Do not use appliances like hairdryers or electric razors near sinks or tubs.
  • Check electrical panels – Ensure all wiring to the electrical service panel is in good repair. Fuses should be properly sized. Contact an electrician if you have recurring tripped breakers, blown fuses, flickering lights, or burning smells from outlets.
  • Use caution during storms – Disconnect appliances and avoid using landline phones, electrical items, plumbing fixtures, or anything connected to a building’s electrical system during storms.
  • Keep children safe – Install tamper-resistant outlets. Keep appliances and cords out of a child’s reach. Do not let children fly kites near power lines.

Exercising proper respect for electricity at all times offers the best protection against severe electrical shock and electrocution.

Preventing Electrical Fires

Along with posing a shock hazard, electrical system issues are the leading cause of residential fires. However, you can prevent electrical fires by taking these steps:

  • Do not overload circuits – Avoid plugging too many devices into one outlet. Upgrade electrical panel amperage if needed.
  • Use heavy gauge extension cords – Never substitute lightweight extension cords or power strips for permanent wiring. The gauge should match the amperage rating of the circuit.
  • Keep combustibles away from electrical equipment – Prevent dust buildup and never stack items on or around electrical devices or outlets.
  • Replace damaged wiring – Upgrade any outdated, damaged, or deteriorated wiring. Aluminum wiring and knob-and-post wiring found in older homes is prone to fire hazards if not replaced.
  • Hire an electrician for major work – Only licensed electricians should handle installing new circuits, replacing service entrance cables, upgrading panels, or major projects.
  • Install AFCIs – Arcing faults create intensely hot sparks and are a major cause of electrical fires. Have arc-fault circuit interrupters professionally installed to halt arcing before it can start a fire.

With proper precautions, you can keep your home’s electrical system running safely for years to come. But never hesitate to call an electrician if you notice any potential signs of problems.

First Aid for Electrical Shock

If an electrical accident occurs, it is vital to respond appropriately. Here are the steps for providing first aid following an electrical shock:

  • Shut off power source – If possible, disconnect the power source to prevent further shocks. Do not touch the person being shocked directly while the power remains on.
  • Check for signs of circulation – Once the power is off, check for breathing and a pulse. Begin CPR immediately if the person is not breathing and does not have a pulse.
  • Call emergency services – Have someone call 911 or emergency medical help right away.
  • Assess and treat burns – Look for entry and exit burn marks and dress any burns with clean bandages. Do not use ice.
  • Treat for shock – Keep the person still, comfortable, and warm to prevent onset of shock from the accident.
  • Monitor airway and breathing – Be prepared to provide rescue breathing or CPR if needed until emergency help arrives.
  • Do not move the person – Avoid moving the injured person unless still in contact with the electrical source. Internal injuries may make it unsafe to move them. Wait for paramedic evaluation.
  • Ask the utility to inspect – For home accidents, call the utility company to inspect and fix any electrical issues before restoring power.

Electrical accident victims require rapid, appropriate emergency care and medical treatment to survive and recover from internal injuries. All homes should have GFCIs installed and stocked first aid kits to respond safely to electrical shock incidents.

When to Call an Electrician

Only licensed electricians should handle major electrical work in a home. Contact a professional electrician immediately if you experience:

  • Repeated tripped breakers or blown fuses
  • Flickering or dimming lights
  • Buzzing, sizzling, or humming sounds from outlets or switches
  • Unusual odors or smoke from outlets
  • Severe shocks or tingling from appliances, outlets, or cords
  • Blackened power outlets or cracked/scorched outlet covers
  • Warm or discolored light switches or electrical outlets
  • Visible sparks or arcing anywhere
  • Damaged, outdated, or dangerous wiring

Signs like these indicate potentially hazardous electrical issues that require professional repair services. Attempting DIY electrical repairs when unqualified puts you and your family at risk of electrical fires, shocks, or electrocution. Trained electricians have the expertise to accurately assess problems and make repairs safely.


Understanding the difference between amperage and voltage provides critical insight into the true hazards posed by electrical shocks. While voltage enables current to push through our bodies, amperage determines how much current flows through us and causes disruption to biological processes, burns, and injury. Exercise caution around all electrical devices, outlets, cords, and power lines. Follow basic safety precautions such as using GFCIs, keeping electrical components in good repair, and avoiding contact with electricity near water. If electrical issues arise in your home, trust only professional electricians to handle repairs and provide a safe electrical environment for your family. Respecting the power of electrical current saves lives.

Frequently Asked Questions About Amperage vs. Voltage: The Dangers of Electrical Shock

Here are some commonly asked questions about the hazards posed by amperage and voltage in electrical shocks:

How much current is dangerous to the human body?

As little as 10-20 milliamps (mA) can be felt. Any current over 100-200 mA poses risk of muscle contractions, respiratory failure, and cardiac arrest. Current over 500 mA often causes severe burns or fatal organ damage.

Which is more dangerous, amperage or voltage?

Both contribute to electrical shock risks. Amperage determines how much current flows through the body, while voltage enables the current to overcome skin resistance. High amperage and high voltage together pose the greatest risk of a dangerous or lethal shock.

What kind of voltage is in my home?

A standard U.S. home electrical service provides 120/240 volt, 60 Hz AC power. Large appliances may use the 240 volt supply, while smaller devices rely on 120 volt outlets. Electrical service in many countries provides 220-250 volts.

Can you get electrocuted by 120 volts?

Yes, 120 volts provides enough push to send a dangerous or even lethal amount of current through the body under certain conditions. Any amount of electrical current over 100 mA poses a potentially deadly risk.

What raises the risk of being electrocuted?

Wet skin or surroundings, damaged cords or outlets allowing contact with live wires, inadequate circuit breakers, and high voltages exponentially increase risks. Medical conditions like heart disease also raise chances of dying from an electrical shock.

How can I prevent electrical accidents in my home?

Use GFCIs, keep appliances and outlets in good repair, fix all electrical issues immediately, keep water away from electricity, and teach children to avoid outlets and electrical cords.

If someone is being shocked, how should you help them?

Shut off the power source immediately, then check for breathing and circulation. Call 911, and if needed, begin CPR. Do not touch the person if they remain in contact with the power source. Have all electrical issues fixed by a qualified electrician after an accident.


Electrical power brings many benefits but also introduces severe risks if misused or handled carelessly. Understanding the physics of amperage and voltage provides the knowledge needed to appreciate how electrical shock disrupts the human body with possibly deadly results. Exercise great caution when working around electricity, especially near water or with appliances in questionable condition. Teach children about electrical hazards. With caution and respect, the risks of electrocution or electrical fires can be minimized. Protect your family by reducing electrical dangers in your home environment.