Page 392 - IGC BOOK

Severity of the Electric Shock Depends On:

• Voltage – the higher the voltage, the greater the current flow through the body.
• Duration – the duration exposed by a person to an electric shock has the potential to cause
more severity. 60 mA of AC current for 30 milliseconds (mS) can cause fibrillation, however if
the same current flow through the body for a second or two, this has potential to cause fatal.

• Current path – electricity takes the shortest path to reach earth to complete the circuit. If shock
received at shoulder level, it may flow through vital organs and heart.

• Resistance - any impedance in the current path based on the skin condition whether dry, wet
or any cuts. The resistance is affected by
- Contact skin surface – more skin contact with live electricity with low resistance, the more
current flow to the body causes severe injuries.
- Environment – A shock received in a wet area would probably be more severe than in a
dry area.

- Clothing and footwear – high resistance will reduce the flow of electricity on to the body.
• Frequency – AC current or DC current.
Contact with alternating current above 60mA can prove fatal, particularly in wet condition. In such
wet condition, the electricity can cause ventricular fibrillation or cardiac arrest.

Electric Burns

Electrical burns are due to heating effect caused by
the passage of electric current through body tissues.
This can be extremely painful and slow to heal leaving
a permanent scarring.

Electrical burns can be through direct contact with
live conductors or indirectly from using a damaged
electrical equipment where the live parts are exposed
outside or other conducting materials become live.

Direct Contact: means a contact of a person or
implement a person is holding with a live conductor
that is supposed to be live. This may be caused by:
unsafe work practices, e.g. touching an overhead power line with a scaffold pole; and faulty or
ineffective insulation of conductors, e.g. damaged insulation or cracked plugs;

Indirect Contact: which occurs when there is contact with a conductor that should not be live
under normal conditions, but is live through a fault: poorly designed or maintained electrical
equipment or circuits which ‘Short Circuit’, the current taking an unintended path to earth, e.g.
where the damaged insulation on an electric drill touches a steel workbench; and electrical
equipment being used in an environment for which it is unsuitable, e.g. use of 230V tools
outdoors in the rain.

ENSIGN | Unit IG2 – Element 11 – Electricity 3