Fire and Intrusion: ICC strengthens CO smoke detector codes

Jan. 15, 2010
System Sensor’s David George looks at the ICC’s new requirements for carbon monoxide, smoke detectors

The International Code Council (ICC) has published new requirements for carbon monoxide (CO) detection and revised requirements for smoke detectors. These provisions are covered in the ICC’s International Residential Code (IRC) for one- and two-family dwellings and townhouses and occurred when the ICC membership overturned two recommendations of the IRC committee.

The ICC implements the IRC as a model code regulation, which is proposed, debated and created for adoption and implementation in municipalities, counties and states that enforce building code regulations. The ICC codes are rapidly becoming the “code of choice” for state and local governments that adopt and enforce building code standards.

Validating CO

The change with the greatest impact is the new IRC mandate requiring single-station CO detection in certain new and existing one- and two- family dwellings and townhouses. Detectors must meet Underwriters Laboratories (UL) 2034, the standard requiring single- and multiple-station CO alarms, to be designed to detect elevated levels of CO and sound an alarm when CO reaches a health threatening level. The new code covers newly constructed dwellings within which fuel-fired appliances are installed or have attached garages and existing dwellings that require a permit for remodel within which fuel-fired appliances exist or have attached garages. These new provisions will go into effect with governmental unit adoption of the 2009 edition of the IRC.

It is important to note that even though the 2009 edition of the IRC references single-station CO alarms, it should not prevent UL 2075-listed system-connected CO detectors from being used. This is because UL 2075 system-connected CO detectors are required to have the same alarm thresholds as UL 2034-listed CO alarms and the 2009 edition of NFPA 720 references UL 2075 system-connected CO detectors as acceptable.

Yet, municipalities such as Chicago have had CO mandates for more than a decade. And state laws and local ordinances requiring CO alarms in residences and other dwellings have been enacted in hundreds of communities in 23 states, most recently Michigan and Georgia.
The long lag time is due, in part, to the insufficient technical data to support the mandatory installation of CO alarms. The IRC committee also urged the industry to address the issues of reliability and false positive indications.

Two important documents changed the course of the IRC’s CO detection mandates. First, technical data from a UL study supports the reliability and false alarm immunity of CO alarms. This five-year UL study, CO Alarm Field Study, evaluated the effectiveness of CO alarms. The study concluded that CO alarms provide effective signaling protection when there are dangerous concentrations of CO. In addition, the study demonstrated that CO alarms generally do not emit false alarms in the field.

Second, the 2006 Technical Committee for NFPA 720, Standard for the Installation of Carbon Monoxide (CO) Detection and Warning Equipment, conducted a complete rewrite of the standard in order to keep up with the trend in state legislation requiring the installation of CO detectors. The adoption of the 2009 edition of NFPA 720 provides the industry with a national CO detector installation standard for all buildings, not just dwelling units. NPFA 720 adds credibility to the reliable performance of CO detectors.

Additionally, there are currently 23 states that require the installation of CO detection in dwellings and, in some cases, commercial buildings without any major reliability issues.
The new requirement for CO detectors represents a critical step toward developing these requirements at the state and local levels.

Fire alarm systems changing course

Another major change is that fire alarm systems using system-connected smoke detectors can now be the primary form of household smoke detection if they are monitored by an approved supervising station and maintained in accordance with NFPA 72.

The 2006 edition of the IRC had restricted this use under the assumption that a home would be left without smoke detection if the homeowner failed to pay the monitoring fee of a household fire alarm system because the supervising station would remotely disable the control panel or have the control panel physically removed. To the contrary, if the household fire alarm system is owned by the homeowner and the homeowner fails to pay the supervising station for the remote monitoring function, it will result in disablement of the remote monitoring function only and the smoke detection at the home is fully maintained.

Consequently, the amended 2006 IRC code, specifically section R 313.1, requires household fire alarm systems (using UL 268-listed smoke detectors connected to a UL 985-listed control panel) to continue operating and to provide the same level of protection as interconnected smoke alarms in the event the control panel is removed or the system is not connected to a central station.
The new language essentially precludes household fire alarm systems from being installed as a primary or supplementary system for smoke detection in the 14 states (Georgia, Idaho, Iowa, Kentucky, Louisiana, Maryland, Minnesota, Montana, New Hampshire, New Jersey, Oregon, Rhode Island, Utah and Washington) that have adopted the 2006 edition of the IRC. This is because no products on the market today meet this requirement.

Furthermore, the new language in the 2006 edition is not technically possible for larger homes that require more than 12 smoke detectors. Section of NFPA 72 limits the number of multiple station alarms to be interconnected to 12 if the interconnecting means is unsupervised.

It will take several years for the household system restriction to be amended because the states that have adopted the 2006 edition of the IRC will have to adopt the 2009 edition.

Both actions are good for the industry. More importantly, they will certainly enhance public life safety. The ICC implementation will occur this month. Individual state/local jurisdiction adoptions will begin in 2010.


The requirements for UL 2034, Standard for Single and Multiple Station Carbon Monoxide Alarms cover electrically operated single and multiple station carbon monoxide (CO) alarms intended for protection in ordinary indoor locations of dwelling units, including recreational vehicles, mobile homes and recreational boats with enclosed accommodation spaces and cockpit areas.

David George is the director of Communications for System Sensor, based in St. Charles, Ill.,