Electricity is a serious health and safety hazard when not handled properly.
Fire — Electricity is the most-common source of workplace fires.
Explosion — During an electrical arc, copper expands 67,000× as it is vaporized. Like dynamite, eye and ear damage commonly occur.
Shock — May cause nerve and tissue damage and possible cardiac arrest.
Thermal Burns — Due to contact with arc plasmas and adjacent heated materials.
Direct Burns — Due to conductance of muscle and organ tissues. Internal damage may not be apparent for many days.
The Shocking Facts: How electricity affects your body
Shock is the nerve sensation and muscle spasm caused by electric current flowing through the body.
Shock occurs when your body becomes part of a circuit.
The severity of shock is determined by three factors:
the amount of current flowing through your body,
the path the current takes through your body, and
the total time current flows through your body.
Effects of current on the human body
General relationship for a 60-cycle, 1-second-duration shock:
Reaction in body
Not painful but disturbing
6 to 25 mA
Painful shock, muscular reaction
9 to 30 mA
Frozen to conductor
50 to 150 mA
Extreme pain, respiratory arrest, contractions
1 to 4 A
Cardiac arrest, severe burns
Notice that the difference of <100 milliamperes (mA) exists between a current that is disturbing, but not painful, and one that can kill!
Not being able to "let go" due to muscle contractions increases the duration of shock. A current of 100 mA for 3 seconds is equivalent to 900 mA for 0.03 seconds, in effect causing ventricular fibrillation.
The dangers of high-voltage electricity:
Cuts and bruises
Variables that contribute to your skin’s resistance to electricity:
Amount of moisture on your skin
Below 600 volts, dry skin is 100× more resistive
A finger contact is higher resistance than a whole hand.
Pressure of contact
Greater pressure decreases resistance, increases the likely burn.