Generator Safety and Placement: CO Risk

Why CO Kills in "Safe" Situations

Carbon monoxide is produced by any incomplete combustion of fuel — gasoline, propane, natural gas, diesel. A running generator is a continuous CO source. CO is odorless and colorless. You will not smell it or see it.

At low concentrations (50-200 ppm), CO causes headache, dizziness, and nausea — symptoms that feel like the flu. At higher concentrations, it causes loss of consciousness rapidly. At 1,200 ppm, loss of consciousness can occur within minutes. CO binds to hemoglobin 200 times more effectively than oxygen — your blood carries it instead of oxygen to your organs.

The CPSC estimates that portable generators cause more than 70 deaths in the United States annually. The majority occur when generators are run inside a garage or basement, or very close to the structure.

What makes this deadly: the symptoms of CO poisoning at moderate levels include confusion and disorientation. People who are incapacitated by CO often cannot recognize what is happening and cannot escape.

Placement Rules

The 20-foot rule is the CPSC's minimum standard. 20 feet from any door, window, or vent. This applies in all directions — your neighbor's house matters too.

Exhaust direction: Most generators exhaust from a specific side. Orient the generator so the exhaust faces away from your house. In areas with prevailing wind, orient exhaust downwind.

Avoid confined spaces adjacent to the house: Even outside, a generator placed in a narrow side-yard between two structures, or under a covered patio attached to the house, can accumulate CO in ways that open-field placement does not.

Elevation: CO is slightly lighter than air but mixes quickly. On a flat surface, CO from ground-level exhaust can still flow along the ground toward low openings (crawl space vents, dryer vents, foundation gaps).

In rain: Use a generator tent or cover that allows full air circulation. Many generator covers exist specifically for wet-weather operation — they have open sides that allow ventilation while keeping water off the unit. Do not create an enclosed space over the generator, even a tarp tent with closed sides.

CO Detector Requirements

One battery-powered CO detector per floor minimum. Two per floor in larger homes.

Placement: CO detectors should be installed on the wall approximately 5 feet above the floor or on the ceiling. CO mixes with room air fairly quickly — it's not purely floor-level like propane (which is heavier than air) or ceiling-level like hydrogen (which is lighter).

Near sleeping areas is critical. People die in their sleep from CO poisoning during generator use — they enter an unconscious state from which they cannot recover without intervention. A CO alarm outside bedroom doors is the difference.

Test monthly. Most CO detectors have a test button. Use it. CO detectors have finite lifespans (5-7 years) — check manufacture date and replace accordingly.

Battery backup: Combo smoke/CO detectors with battery backup are adequate. Pure battery CO detectors are better during a power outage scenario where the unit may be in use for extended periods.

Extension Cord and Load Management

Cord gauge: Undersized extension cords are a fire risk when driving significant loads. Use 12-gauge cords for loads up to 1,875 watts (15 amps at 125 volts). Use 10-gauge for higher loads. 16-gauge lamp cords are never appropriate for generator connections.

Cord length: Longer cords have higher resistance, which means more voltage drop and more heat generation under load. Keep runs as short as practical. A 100-foot 12-gauge cord is marginal for high loads — use a shorter, heavier cord when possible.

Never run through windows or doors: Cords pinched in window frames and door gaps degrade the insulation and create fire risk. Use window inserts or door inserts with built-in pass-through ports, or position the generator where cords can run around rather than through closed openings.

Load calculation: Add up the wattage of everything you plan to connect. Your generator should run at no more than 80% of its rated output continuously. Running at 100% capacity continuously reduces generator life and increases operating temperature.

Maintenance

A generator that won't start in an emergency is useless. Run it monthly for 30 minutes under load. Change oil per manufacturer schedule (typically after first 5-20 hours, then every 50-100 hours). Use fuel stabilizer in stored gasoline if the generator sits unused for more than 30 days. Old, oxidized gasoline is one of the primary causes of generator failure.

Keep 5-10 gallons of stabilized fuel stored in approved containers (red fuel jugs with venting caps). Rotate it every 6-12 months.