frayed or damaged extension cords.

Ensure the cords are appropriately rated in

watts or amps for the intended use. Do not

use underrated cords—replace them with

appropriately rated cords that use heavier

gauge wires. Do not overload a generator;

this can lead to overheating which can create a fire hazard.

• Use ground fault circuit interrupters

(GFCIs), especially where electrical equipment is used in or around wet or damp

locations. GFCIs shut off power when an

electrical current is detected outside normal paths. GFCIs and extension cords with

built-in GFCI protection can be purchased

at hardware stores, do-it-yourself centers,

and other locations that sell electrical

equipment. Regardless of GFCI use, electrical equipment used in wet and damp

locations must be listed and approved for

those conditions.

• Make sure a generator is properly grounded and the grounding connections are

tight. Consult the manufacturer's instructions for proper grounding methods.

• Keep a generator dry; do not use it in the

rain or wet conditions. If needed, protect a

generator with a canopy. Never manipulate

a generator’s electrical components if you

are wet or standing in water.

• Do not use electrical equipment that has

been submerged in water. Equipment

must be thoroughly dried out and properly

evaluated before using. Power off and do

not use any electrical equipment that has

strange odors or begins smoking. 

Hazards Associated with Generators:

• Shocks and electrocution from improper

use of power or accidentally energizing

other electrical systems. 

• Carbon monoxide from a generator’s

exhaust.

• Fires from improperly refueling a generator

or inappropriately storing the fuel for a generator.

• Noise and vibration hazards.

Shock and Electrocution

The electricity created by generators has the

same hazards as normal utility-supplied electricity. It also has some additional hazards

because generator users often bypass the

safety devices (such as circuit breakers) that

are built into electrical systems. The following precautions are provided to reduce shock

and electrocution hazards:

• Never attach a generator directly to the

electrical system of a structure (home,

office, trailer, etc.) unless a qualified electrician has properly installed the generator

with a transfer switch. Attaching a generator directly to a building electrical system

without a properly installed transfer switch

can energize wiring systems for great distances. This creates a risk of electrocution

for utility workers and others in the area.

• Always plug electrical appliances directly

into the generator using the manufacturer’s

supplied cords or extension cords that are

grounded (3-pronged). Inspect the cords to

make sure they are fully intact and not

damaged, cut or abraded. Never use

FactSheet

Using Portable Generators Safely

Portable generators are internal combustion engines used to generate electricity.

They are useful when temporary or remote power is needed, and are commonly

used during cleanup and recovery efforts following disasters such as hurricanes,

tornadoes, etc. This fact sheet discusses specific hazards inherent with the use

of generators and also provides helpful information to ensure that workers and

others using such equipment remain safe.
Carbon Monoxide Poisoning

Carbon monoxide (CO) is a colorless, odorless, toxic gas. Many people have died from

CO poisoning because their generator was

not adequately ventilated.

• Never use a generator indoors or in

enclosed spaces such as garages, crawl

spaces, and basements. NOTE: Open windows and doors may NOT prevent CO from

building up when a generator is located in

an enclosed space.

• Make sure a generator has 3 to 4 feet of

clear space on all sides and above it to

ensure adequate ventilation. 

• Do not use a generator outdoors if its

placement near doors, windows, and vents

could allow CO to enter and build up in

occupied spaces. 

• If you or others show symptoms of CO poisoning—dizziness, headaches, nausea,

tiredness—get to fresh air immediately and

seek medical attention. Do not re-enter the

area until it is determined to be safe by

trained and properly equipped personnel.

Fire Hazards

• Generators become hot while running and

remain hot for long periods after they are

stopped. Generator fuels (gasoline,

This is one in a series of informational fact sheets highlighting OSHA programs, policies or 

standards. It does not impose any new compliance requirements. For a comprehensive list of 

compliance requirements of OSHA standards or regulations, refer to Title 29 of the Code of Federal

Regulations. This information will be made available to sensory impaired individuals upon request.

The voice phone is (202) 693-1999; teletypewriter (TTY) number: (877) 889-5627.

kerosene, etc.) can ignite when spilled on

hot engine parts.

• Before refueling, shut down the generator

and allow it to cool. 

• Gasoline and other generator fuels should

be stored and transported in approved containers that are properly designed and

marked for their contents, and vented. 

• Keep fuel containers away from flame producing and heat generating devices (such

as the generator itself, water heaters, cigarettes, lighters, and matches). Do not

smoke around fuel containers. Escaping

vapors or vapors from spilled materials can

travel long distances to ignition sources. 

• Do not store generator fuels in your home.

Store fuels away from living areas. 

Noise and Vibration Hazards

• Generator engines vibrate and create noise.

Excessive noise and vibration could cause

hearing loss and fatigue that may affect job

performance.

• Keep portable generators as far away as

possible from work areas and gathering

spaces.

• Wear hearing protection if this is not possible.

U.S. Department of Labor

www.osha.gov

(800) 321-OSHA

For more complete information:

DSTM 9/2005