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Electrical Safety Glossary

ampacity - maximum amount of current a wire can carry safely without over-heating
amperage - strength of an electrical current, measured in amperes
ampere (amp) - unit used to measure current
arc-blast - explosive release of molten material from equipment caused by high-amperage arcs
arcing - luminous electrical discharge (bright, electrical sparking) through the air that occurs when high voltages exist across a gap between conductors
AWG - American Wire Gauge-measure of wire size
bonding - joining electrical parts to assure a conductive path
bonding jumper - conductor used to connect parts to be bonded
circuit - complete path for the flow of current
circuit breaker - overcurrent protection device that automatically shuts off the current in a circuit if an overload occurs
conductor - material in which an electrical current moves easily
CPR - cardiopulmonary resuscitation-emergency procedure that involves giving artificial breathing and heart massage to someone who is not breathing or does not have a pulse (requires special training)
current - movement of electrical charge
de-energize - shutting off the energy sources to circuits and equipment and depleting any stored energy
double-insulated - equipment with two insulation barriers and no exposed metal parts
energized (live, "hot") - similar terms meaning that a voltage is present that can cause a current, so there is a possibility of getting shocked
fault current - any current that is not in its intended path
fixed wiring - permanent wiring installed in homes and other buildings
flexible wiring - cables with insulated and stranded wire that bends easily
fuse - overcurrent protection device that has an internal part that melts and shuts off the current in a circuit if there is an overload
GFCI - ground fault circuit interrupter-a device that detects current leakage from a circuit to ground and shuts the current off
ground - physical electrical connection to the earth
ground fault - loss of current from a circuit to a ground connection
ground potential - voltage a grounded part should have; 0 volts relative to ground
guarding - covering or barrier that separates you from live electrical parts
insulation - material that does not conduct electricity easily
leakage current - current that does not return through the intended path, but instead "leaks" to ground
lock-out - applying a physical lock to the energy sources of circuits and equipment after they have been shut off and de-energized
milliampere (milliamp or mA) - 1/1,000 of an ampere
NEC - National Electrical Code-comprehensive listing of practices to protect workers and equipment from electrical hazards such as fire and electrocution
neutral - at ground potential (0 volts) because of a connection to ground
ohm - unit of measurement for electrical resistance
OSHA - Occupational Safety and Health Administration-Federal agency in the U.S. Department of Labor that establishes and enforces work-place safety and health regulations
overcurrent protection device - device that prevents too much current in a circuit
overload - too much current in a circuit
power - amount of energy used each second, measured in watts
PPE - personal protective equipment (eye protection, hard hat, special clothing, etc.)
qualified person - someone who has received mandated training on the hazards and on the construction and operation of equipment involved in a task
resistance - material's ability to decrease or stop electrical current
risk - chance that injury or death will occur
shocking current - electrical current that passes through a part of the body
short - low-resistance path between a live wire and the ground, or between wires at different voltages (called a fault if the current is unintended)
tag-out - applying a tag that alerts workers that circuits and equipment have been locked out
trip - automatic opening (turning off) of a circuit by a GFCI or circuit breaker
voltage - measure of electrical force
wire gauge - wire size or diameter (technically, the cross-sectional area)


1. Castillo DN [1995]. NIOSH alert: preventing death and injuries of adolescent workers. Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 95-125.

2. Lee RL [1973]. Electrical safety in industrial plants. Am Soc Safety Eng J 18(9):36-42.

3. DOL [1997]. Controlling electrical hazards. Washington, DC: U.S. Department of Labor, Occupational Safety and Health Administration.

OSHA Standards
OSHA occupational safety and health standards for General Industry are located in the Code of Federal Regulations (CFR), Title 29, Part 1910 (abbreviated as 29 CFR 1910). Standards for Construction are located in Part 1926 (abbreviated as 29 CFR 1926). The full text of these standards is available on OSHA's Web site:

OSHA standards related to electrical safety for General Industry are listed below:

Subpart S-Electrical
1910.301 - Introduction

1910.302 - Electric utilization systems
1910.303 - General requirements
1910.304 - Wiring design and protection
1910.305 - Wiring methods, components, and equipment for general use
1910.306 - Specific purpose equipment and installations
1910.307 - Hazardous (classified) locations
1910.308 - Special systems

1910.331 - Scope
1910.332 - Training
1910.333 - Selection and use of work practices
1910.334 - Use of equipment
1910.335 - Safeguards for personnel protection

Subpart J-General Environment Controls
1910.147 - The control of hazardous energy (lock-out/tag-out)
1910.147 - Appendix A-Typical minimal lock-out procedures

Subpart R-Special Industries
1910.268 - Telecommunications
1910.269 - Electric power generation, transmission, and distribution
OSHA standards related to electrical safety for Construction are listed below:

Subpart K-Electrical
1926.400 - Introduction

1926.402 - Applicability
1926.403 - General requirements
1926.404 - Wiring design and protection
1926.405 - Wiring methods, components, and equipment for general use
1926.406 - Specific purpose equipment and installations
1926.407 - Hazardous (classified) locations
1926.408 - Special systems

1926.416 - General requirements
1926.417 - Lock-out and tagging circuits

1926.431 - Maintenance of equipment
1926.432 - Environmental deterioration of equipment

1926.441 - Batteries and battery charging
1926.449 - Definitions applicable to this subpart

Subpart V-Power Transmission and Distribution
1926.950 - General requirements
1926.951 - Tools and protective equipment
1926.952 - Mechanical equipment
1926.953 - Material handling
1926.954 - Grounding for protection of employees
1926.955 - Overhead lines
1926.956 - Underground lines
1926.957 - Construction in energized substations
1926.958 - External load helicopters
1926.959 - Lineman's body belts, safety straps, and lanyards
1926.960 - Definitions applicable to this subpart

To receive information about occupational safety and health problems, call NIOSH at
1-800-35-NIOSH (1-800-356-4674)
Fax number: (513) 533-8573
or visit the NIOSH Web site at

DHHS (NIOSH) Publication No. 2002-123