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Portable Generator Hazards

Portable generators are handy and widely used after storms, yet they are linked to serious injuries. Knowing the hazards helps you decide how and when to use one.

What are the main hazards?

Four hazards come up repeatedly in safety guidance: carbon monoxide from exhaust, fire from fuel and hot parts, shock from wet or damaged equipment and backfeed from improper connections. Overloading can add damage and fire risk.

None of these are rare. They are the predictable results of using a small engine and a source of electricity in rough conditions.

Many people hurt by generators were using them for the first time during an outage, which is another reason to practice before one happens.

How does carbon monoxide harm people?

Carbon monoxide is produced by engines and can build up in enclosed spaces. It cannot be seen or smelled. Exposure can cause headache, dizziness, nausea, weakness and confusion, and can be life threatening.

Run units only outdoors, away from openings to buildings. If someone feels ill near a running engine, move to fresh air and call 911. Do not return until responders say it is safe.

Carbon monoxide can also seep through gaps and shared walls, so keep units well clear of every building, including neighbors'.

• Headache or dizziness near a running engine
• Nausea or weakness
• Confusion or unusual drowsiness
• Anyone with these signs needs fresh air and a 911 call

What are the fire risks?

Gasoline and other fuels give off vapor that can ignite from sparks or hot surfaces. Engines and exhaust stay hot after shutdown. Refueling a hot engine or storing fuel near the unit is a recognized cause of fires.

Let the engine cool before adding fuel, use approved containers and keep fuel away from living areas, heaters and ignition sources. Keep dry vegetation and bedding well clear.

Never smoke near fuel or the unit, and do not store fuel in living spaces.

• Use approved fuel containers
• Store fuel away from the generator and from living areas
• Keep ignition sources far from refueling
• Do not top off a tank near a hot engine

What are the shock risks?

Wet conditions, frayed cords and poor connections increase shock risk. Use cords made for outdoor use and rated for the load, keep connections dry and avoid touching equipment with wet hands.

Ask an electrician about protective devices suited to your equipment, and read the manual for any specific instructions on grounding, which vary by model.

Look over the cord ends at each use for bent prongs, melted plastic and cracked insulation.

Why is backfeed a hazard?

Connecting a generator to a building the wrong way can send power back into utility lines, endangering line workers. Always use equipment installed by a licensed electrician, as described in the guide on backup generator wiring.

If you are unsure how your generator is connected, stop using it and have it checked.

• Never use an improvised connection
• Do not backfeed through a dryer or welder outlet
• Ask an electrician about proper equipment
• Warn others who borrow the unit

How do you reduce overload and wear?

Add up the needs of what you plan to run and compare with the generator's labeled capacity. Start the largest loads first and stagger motors. Keep the air filter, oil and spark plug in good shape, following the manual.

Store the unit with fuel treated or drained as the manufacturer advises, and run it periodically so it works when needed.

Keep a record of the last fuel treatment and the last test run, so you do not have to guess when you need the unit.

• Add up the labeled needs of everything you plan to run
• Start the largest motor first and add smaller loads after
• Follow the manual for oil, filter and spark plug care

What other habits protect you?

Keep children and animals away from the unit and its exhaust. Read the manual before an outage, and keep it with the generator. Keep a charged fire extinguisher nearby.

Consider whether you can use a safer alternative for short jobs, such as battery tools or waiting for power to return. If a unit smokes, sparks or acts strangely, shut it down and have it repaired.

Share these habits with anyone who borrows your equipment.

• Read the manual before the outage
• Keep a charged extinguisher nearby
• Keep children and animals back
• Shut down and repair a unit that smokes or sparks

Last reviewed: November 12, 2026. Written by the Farm Safety Editorial Team. See our editorial policy.