Electrical Hazards on Construction Sites
Electricity can injure or kill in several ways:
Electric Shock
- Happens when current travels through your body
- As little as 10 milliamps can cause painful shock
- 100 milliamps can be fatal
- Severity depends on amount of current, path through body, and duration
Arc Flash/Blast
- Explosive release of energy
- Can cause severe burns, blindness, hearing damage
- Can throw workers across rooms
- Can ignite clothing and cause fires
Fire
- Faulty wiring or overloaded circuits
- Damaged insulation
- Improper use of equipment
- Combustible materials near heat sources
Falls
- Often result from shock or startling
- Secondary injury after electrical contact
- Can be more serious than the shock itself
Common Electrical Hazards
Overhead Power Lines
- Leading cause of electrical fatalities
- Always assume lines are energized
- Maintain at least 10 feet distance (more for higher voltages)
- Use spotters when operating equipment near lines
Damaged Tools and Equipment
- Cracked casings
- Damaged cords or plugs
- Missing grounding pins
- Exposed wiring
Improper Grounding
- Missing ground pins
- Improper wiring
- Using two-prong adapters on three-prong tools
Wet Conditions
- Water greatly increases electrical hazards
- Never use electric tools in wet locations unless specifically designed for it
- Keep cords and equipment away from water
Overloaded Circuits
- Too many devices on one circuit
- Can cause overheating, fires, and equipment damage
- Use proper gauge extension cords for the amperage needed
Safe Work Practices
Before Work Begins
- Identify all electrical hazards in the work area
- Locate and identify utilities before digging
- Ensure all workers are trained on electrical hazards
- Plan work to avoid electrical dangers
When Using Electrical Equipment
- Inspect all tools and cords before use
- Don't use damaged equipment - tag it and remove from service
- Keep cords away from heat, oil, and sharp edges
- Don't carry tools by their cords
- Disconnect tools when not in use
Extension Cords
- Use the right cord for the job (gauge, length, indoor/outdoor rating)
- Don't remove ground pins or use adapters
- Don't run cords through doorways, windows, or holes without protection
- Don't use staples or nails to secure cords
- Uncoil cords completely when in use
Working Near Power Lines
- Maintain proper clearance (at least 10 feet for most voltages)
- Use non-conductive ladders (fiberglass) near electricity
- Have power lines de-energized when possible
- Use warning signs and barriers around overhead lines
Temporary Power
- Use GFCI protection
- Protect temporary wiring from damage
- Route cords overhead when possible
- Use weatherproof boxes and connections outdoors
Ground Fault Circuit Interrupters (GFCIs)
- Required on all construction sites for temporary power
- Cuts power when it detects current leakage
- Test GFCIs before each use with the "Test" button
- Can save your life by preventing electrocution
- Available as outlets, extension cords, or plug-in devices
Lockout/Tagout Procedures
When working on electrical equipment:
- Turn off the power
- Disconnect the equipment from power source
- Apply a lock to prevent others from turning power back on
- Apply a tag identifying who locked it and why
- Verify the equipment is de-energized by trying to turn it on
- Complete the work
- Remove locks and tags when work is finished
If Someone Is Being Shocked
- Don't touch them - you could be shocked too
- Turn off the power source immediately
- Use a non-conductive object to separate victim from source if necessary
- Call for emergency help
- Provide first aid if trained to do so