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St. Louis, MO Building Safety: Carbon Monoxide Detectors (2026)

Some Restrictions
Compiled from the official code textEditor Martyn O'NeillLast verified September 2026

Key Facts

Applies to
New or rehabbed buildings, fossil-fuel heat
Single-family
1+ detector outside sleeping area
Multi-family
1 detector in every unit
Standard
UL 2034 (10-1-1995) or later
Penalty
$50–$500 fine, up to 90 days

Summary

St. Louis requires at least one approved carbon monoxide detector in every new or rehabbed residential building heated by a fossil-fuel unit, with violations punishable by fine or jail.

The owner of every new building or structure within the City of St. Louis which is intended to be occupied for residential purposes by a single family and every single-family residential building or structure which is rehabbed after the effective date of the ordinance codified in this chapter, and which is heated by a fossil fuel powered heating unit which is fully contained within the interior of the building or structure, shall install not less than one (1) approved carbon monoxide detector outside the area of sleeping rooms and additional units as required by the Fire Marshal.

View official code

Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 11).

Full Breakdown

City code requires the owner of any new single-family building, or one rehabbed after the ordinance's effective date, that is heated by a fossil-fuel-powered unit fully inside the structure to install at least one approved CO detector outside the sleeping-room area, plus additional units the Fire Marshal requires. Multi-family buildings meeting the same fuel and rehab conditions need one approved detector in every unit. An approved detector must carry a nationally recognized testing lab's label and meet UL 2034 (Oct. 1, 1995 revision) or later. Owners must supply, install, test per manufacturer specs, and maintain the detectors and their equipment. Disabling a required detector is unlawful except for normal maintenance like a battery swap.

Violations & Fines

Fine of $50 to $500 and/or up to 90 days confinement; each day a violation continues is a separate offense.

Frequently Asked Questions

Does every St. Louis home need a carbon monoxide detector?
Only new or rehabbed residential buildings heated by a fossil-fuel unit contained inside the structure are required to install one under city code.
Where must the detector go in a single-family home?
Outside the area of sleeping rooms, plus any additional units the Fire Marshal requires, per Section 25.60.020.
Can I remove the batteries from a required CO detector?
Normal maintenance like battery replacement is allowed, but otherwise disabling a required detector is unlawful under Section 25.60.050.

Sources & Official References

Other rules in St. Louis

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