Carbon Monoxide Alarms Shall Comply Withsection R315

SECTIONR315
CARBON MONOXIDE ALARMS

R315.1General.

Carbon monoxide alarms shall comply withSection R315.

❖ Carbon monoxide (CO) is an odorless, colorless and toxic gas. Because it is impossible to see, taste or smell the toxic fumes, CO can kill occupants before they are aware it is in their home. At lower levels of exposure, CO causes mild effects that are often mistaken for the flu. These symptoms include headaches, dizziness, disorientation, nausea and fatigue. The effects of CO exposure can vary greatly from person to person depending on age, overall health, and the concentration and length of exposure. According to theJournal of the American Medical Association(JAMA), CO is the leading cause of accidental poisoning deaths in America.

Sources of CO include unvented kerosene and gas space heaters; leaking chimneys and furnaces; backdrafting from furnaces, gas water heaters, wood stoves and fireplaces; gas stoves; generators and other gasoline-powered equipment; and automobile exhaust from attached garages. Incomplete oxidation during combustion in gas ranges and unvented gas or kerosene heaters may cause high concentrations of CO in indoor air. Worn or poorly adjusted and maintained combustion devices (e.g., boilers, furnaces) can be significant sources, especially if the flue is improperly sized, blocked, disconnected or is leaking. Auto, truck or bus exhaust from attached garages, nearby roads or parking areas can also be a source.

Average levels of CO in homes without gas stoves vary from 0.5 to 5 parts per million (ppm). Levels near properly adjusted gas stoves are often 5 to 15 ppm and those near poorly adjusted stoves may be 30 ppm or higher.

CO alarms and detectors must not be considered a replacement for the proper use and maintenance of fuel-burning appliances. The industry has addressed the issue of reliability by updating the requirements ofUL 2034. All CO detectors available today meet the updated requirements, which eliminated the false positive indications that occurred when CO detectors were first brought to market in the 1990s.

For new construction,Section R315.2.1requires carbon monoxide alarms where dwelling units contain a fuel-fired appliance or have an attached garage with a door at the common wall between the dwelling unit and the garage.

For alterations, repairs and additions that require a permit, or where one or more sleeping rooms are added or created,Section R315.2.2indicates that the requirements are the same as for new construction. However,Section R315.2.2exempts carbon monoxide alarms for work related to plumbing and mechanical systems, as well as work related to exterior surfaces, such as the replacement of siding or roofing or the addition of windows, doors, porches and decks.

Section R315.3requires that CO alarms be located outside each separate sleeping area in the immediate vicinity of the bedrooms. The carbon monoxide alarm can be located near the smoke alarm required in the immediate area of the bedrooms bySection R314.3.Section R315.1.1requires that the alarms be listed in accordance withUL 2034. Alternatively,Sections R315.1.1andR315.4allow combination carbon monoxide alarms and smoke alarms where they are listed in accordance with bothUL 2034andUL 217.

For new construction,Section R315.5requires that carbon monoxide alarms be “hard wired” to the building wiring where the building wiring is from a commercial source, such as a utility company. A battery backup is required so that power is also available when the commercial source is interrupted. For alterations, repairs and additions, the system is permitted to be either battery powered or hard wired.

Section R315.1does not require CO detectors to be hard wired or interconnected like smoke alarms (see CommentaryFigure R315.3).

R315.1.1Listings.

Carbon monoxide alarms shall belistedin accordance withUL 2034. Combination carbon monoxide and smoke alarms shall belistedin accordance withUL 2034andUL 217.