There are many dangers associated with electricity. An accidental shock can cause severe burns, damage to internal organs, and even death. Interestingly, the most dangerous aspect of electrical shock is the amperage, not the voltage. Voltage and amperage are two measures of electrical current or flow of electrons. Voltage is a measure of the pressure that allows electrons to flow, while amperage is a measure of the volume of electrons.
An electrical current at 1,000 volts is no more deadly than a current at 100 volts, but tiny changes in amperage can mean the difference between life and death.
Effects of Amperage on Electrical Shock
Different amounts of amperage affect the human body in different ways. The following list explains some of the most common effects of electrical shock at various amperage levels. To understand the amounts involved, a milliampere (mA) is one-thousandth of an ampere or amp. A standard household circuit that supplies your outlets and switches carries 15 or 20 amps (15,000 or 20,000 mA).
- 1-10 mA
Little or no electrical shock is felt.
- 10-20 mA
Painful shock, but muscle control is not lost.
- 20-75 mA
Serious shock, including a painful jolt and loss of muscle control; victim cannot let go of wire or another source of shock.
- 75-100 mA
Ventricular fibrillation (uncoordinated twitching of ventricles) of the heart can occur.
- 100-200 mA
Ventricular fibrillation occurs, often resulting in death.
- Over 200 mA
Severe burns and severe muscle contractions occur. Internal organs can be damaged. The heart can stop due to chest muscles applying pressure to the heart, but this clamping effect can prevent ventricular fibrillation, greatly improving the chances of survival if the victim is removed from the electrical circuit.
Staying Safe Around Electricity
The best way to prevent electrical shock is to follow standard safety procedures for all electrical work. Here are some of the most important basic safety rules:
- Shut Off the Power
Always turn off the power to a circuit or device that you will be working on. The most reliable way to shut off the power is to switch off the breaker for the circuit(s) in the home's service panel (breaker box).
- Test for Power
After turning a circuit's breaker, check the wiring or devices you will be working on with a non-contact voltage tester to confirm the power is off. This is the only way to be sure you turned off the correct circuit(s)!
- Use Insulated Ladders
Never use an aluminum ladder for electrical work. Always use an insulated fiberglass ladder to keep you safe.
- Stay Dry
Avoid wet areas when working around electricity. If you are outdoors in damp or wet conditions, wear rubber boots and gloves to reduce the chance of getting shocked. Plug power tools and appliances into a GFCI (ground-fault circuit interrupter) outlet or GFCI extension cord. Dry your hands before grabbing any cord.
- Post Warnings
If you are working on the service panel or a circuit, place a warning label on the face of the panel to warn others not to turn on any circuits. Before turning the power back on, make sure no one else is in contact with the circuit.