UL 2201 vs PGMA G300: not the same claim

Last reviewed July 2026.

Two ANSI-approved standards address generator carbon monoxide, and generator marketing tends to blur them into one reassuring blob. They differ in what they require and — just as important for a buyer — in who vouches for compliance.

What each standard requires

• ANSI/PGMA G300 (the industry association's standard, 2018 and 2023 editions) requires a system that shuts the generator off when specified CO concentrations are present near the machine.
• ANSI/UL 2201 requires the shutoff and caps the generator's CO emission rate itself — a lower-emitting engine plus the sensor, which is why CPSC's modeling separates them so starkly.

What CPSC's modeling found

In CPSC's effectiveness analysis, generators compliant with UL 2201 would avert nearly 100% of the CO deaths occurring with non-compliant machines; PGMA G300-compliant machines would avert about 87% (CPSC report). Both are enormous improvements over nothing; they are not equivalent.

Who vouches for compliance — the buyer's question

• UL 2201 is certified: UL controls the testing and maintains a public listing (directory category FTCN). The first certification went to a Ryobi inverter model in 2018. If a listing exists, anyone can look it up; if it doesn't, the claim shouldn't be on the box.
• G300 conformance is self-declared: PGMA publishes the standard; makers state their compliance. A named, dated citation — Honda's G300-2023, Champion's G300-2018 — is a real, falsifiable claim. It is still the maker grading its own homework, which is why our table tiers it below a UL listing and above a brand-name-only "CO-something" feature.

The market reality

CPSC's blunt finding: compliance with UL 2201 "appears to be minimal," and G300 compliance, "although greater, is still lacking for most models or units currently being sold" — against roughly 80 deaths a year. That gap is why a mandatory federal standard has been in rulemaking since 2023, and it's the entire reason to check the standard behind the sticker before hurricane season instead of during it.

Every generator line's claim, tiered by who stands behind it →

We test nothing and give no safety advice — we index standards, listings, manufacturer citations and CPSC's record, with attribution. No shutoff standard makes enclosed-space use safe; CPSC placement guidance governs at every tier.