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:
- Hearing loss
- Eye damage
- Cuts and bruises
- Thermal burns
- Direct burns
- Broken bones
- Cardiac arrest
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
- Contact area
- A finger contact is higher resistance than a whole hand.
- Pressure of contact
- Greater pressure decreases resistance, increases the likely burn.
- Duration of contact
- The longer the contact, the more likely the burn.