A CO shutoff is not permission

Last reviewed July 2026.

This site ranks generators by who stands behind their CO-shutoff claims — so it owes you the other half of the truth: the best shutoff on the market does not make a generator safe to run indoors, in a garage, or near a window. Not one tier of our table changes that.

What the sensor actually does

A compliant system monitors CO concentration near the generator and kills the engine at defined thresholds — Honda publishes its CO-Minder numbers plainly: an immediate shutdown at 600 ppm at the generator, or when a 10-minute average exceeds 400 ppm (Honda's system page). Those thresholds exist because they mark conditions that would soon be lethal in an enclosed space. The sensor is designed to interrupt a mistake already in progress — CO accumulating where it shouldn't be — not to prevent the exposure that happens before shutdown, and not to substitute for placement.

What CPSC's guidance still requires — at every tier

CPSC's placement guidance is unchanged by any shutoff: outdoors only; at least 20 feet from the home; exhaust pointed away from the house; never inside homes, garages, basements, sheds, or near windows, doors or vents (CPSC storm guidance). CPSC's own modeling of the standards assumes the sensor is a mitigation for misuse — the ~100% and ~87% death-aversion figures measure how well the backstop catches mistakes, not a license to make them.

Why we publish this on a ranking site

Because the failure mode of safety-feature marketing is moral licensing: "it has the CO thing" becomes a reason to do what kills people. The honest frame is the one the record supports — buy the strongest standard you can, and then run the machine as if it had no sensor at all. The sensor is for the mistake you didn't plan to make.

The table, with that caveat welded on →

We test nothing and give no safety advice — placement rules above are CPSC's own guidance, quoted with attribution; the linked documents govern. Thresholds cited are the manufacturer's published figures.