Chapter 4 of 520% of exam

Electrical Safety and PPE

Electrocution is one of the Focus Four hazards, and electrical incidents can also cause severe burns and fires. This chapter explains how to control hazardous energy with lockout/tagout, protect against shock with GFCIs and grounding, work safely near power lines, and select the right personal protective equipment. Following these practices keeps workers safe from a hazard that offers little warning.

Lockout/Tagout (LOTO)

Lockout/tagout controls hazardous energy during servicing and maintenance so that equipment cannot start unexpectedly. Energy sources include electrical, mechanical, hydraulic, pneumatic, thermal, and stored energy. A structured LOTO procedure protects workers by isolating and verifying zero energy before work begins.

Purpose of LOTO

Lockout/tagout prevents the unexpected startup or release of hazardous energy while equipment is being serviced.

Only the applier removes the lock

Generally, only the authorized worker who applied a lock may remove it, ensuring no one is still at risk.

Address stored energy

Residual energy in capacitors, springs, hydraulics, or raised parts must be released or restrained before work.

Verify zero energy

After locking out, verify the equipment will not operate and test circuits to confirm they are de-energized.

Shock Protection: GFCIs and Grounding

Ground faults are a leading cause of shock on construction sites, especially with temporary wiring and portable tools. A Ground Fault Circuit Interrupter (GFCI) quickly shuts off power when it detects current leaking to ground. Proper grounding provides a safe path for fault current and must never be defeated.

Use GFCI protection

OSHA requires GFCI protection on temporary receptacles or an assured equipment grounding conductor program on construction sites.

Never remove the ground prong

The grounding prong provides a safe path for fault current and must not be removed or bypassed.

Keep connections dry

Water lowers the body's resistance and greatly increases shock severity, so keep equipment and connections dry.

Inspect cords and tools

Remove damaged cords or tools from service until they are properly repaired or replaced.

Working Near Power Lines

Contact with overhead and underground power lines is a leading cause of electrocution in construction. Workers should treat all lines as energized and maintain a safe clearance that increases with voltage. Special care is needed with cranes, ladders, and scaffolds that can reach a line.

Assume lines are energized

Treat every overhead and buried line as live unless it has been confirmed de-energized and grounded.

Maintain clearance distances

Keep required minimum distances from power lines, and increase the distance as voltage rises.

Safe rescue technique

Never touch a shock victim with bare hands; de-energize the source or use a non-conductive object, then call for help.

Selecting PPE

When hazards cannot be eliminated or controlled by other means, personal protective equipment protects the worker as a last line of defense. Electrical PPE must be rated for the voltage and hazard, including insulating gloves and arc-rated clothing. PPE selection follows a hazard assessment of the specific task.

PPE is the last defense

PPE supplements engineering and work-practice controls but never replaces de-energizing equipment.

Rated insulating gloves

Voltage-rated rubber insulating gloves, often worn with leather protectors, guard against shock when handling energized conductors.

Arc-rated clothing

Arc-rated clothing and face protection reduce burn injuries from an arc flash.

Choose the right hard hat class

Class E hard hats protect against contact up to 20,000 volts, while Class C offers no electrical protection.

Safe Use of Temporary Power

Temporary power and portable tools present unique hazards because wiring is exposed to abuse and weather. Cords must be rated for job-site conditions, protected from damage, and never overloaded. Only qualified persons should perform certain energized electrical tasks.

Use hard-usage cords

Construction extension cords must be rated for hard or extra-hard usage to withstand abrasion and moisture.

Avoid overloading

Overloading circuits or cords causes overheating that can start fires or damage equipment.

Qualified persons only

Only a person trained and knowledgeable in the equipment and its hazards may perform certain energized work.

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Last updated: July 2026