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. 

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 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-ityourself 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.

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.

FactSheet
• 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, 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.

Workers’ Rights

Workers have the right to:

• Working conditions that do not pose a risk 

of serious harm.

• Receive information and training (in a 

language and vocabulary the worker 

understands) about workplace hazards, 

methods to prevent them, and the OSHA 

standards that apply to their workplace.

• Review records of work-related injuries 

and illnesses.

• File a complaint asking OSHA to inspect 

their workplace if they believe there is a 

serious hazard or that their employer is not 

following OSHA’s rules. OSHA will keep all 

identities confidential.

• Exercise their rights under the law without 

retaliation, including reporting an injury or 

raising health and safety concerns with their 

employer or OSHA. If a worker has been 

retaliated against for using their rights, they 

must file a complaint with OSHA as soon as 

possible, but no later than 30 days.

For additional information, see OSHA’s Workers 

page (www.osha.gov/workers).

How to Contact OSHA

Under the Occupational Safety and Health 

Act of 1970, employers are responsible for 

providing safe and healthful workplaces 

for their employees. OSHA’s role is to help 

ensure these conditions for America’s working 

men and women by setting and enforcing 

standards, and providing training, education, 

and assistance. For more information, visit 

www.osha.gov or call OSHA at 1-800-321-OSHA 

(6742), TTY 1-877-889-5627. 

DTSEM FS-3286 09/2005

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.