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Carbon Monoxide and CO Alarms

Emergencies involving deadly carbon monoxide (CO) gas have resulted in important regulations regarding CO and CO detectors. Property owners and renters should be aware of these laws and Baltimore County government's role in preventing, responding to and investigating CO incidents.

CO Alarms and New Construction

A state law enacted in 2007 requires the installation of hardwired CO alarms in a central location outside of each sleeping area within specified dwellings constructed after January 1, 2008. These "specified dwellings" include one- and two-family dwellings, multifamily dwellings (apartments), hotels, motels and dormitories. The bill applies only to dwellings that use fossil fuels for heat, ventilation, hot water or appliance operation.

Prior to issuance of a use and occupancy permit, the Electrical Inspection Section of the Department of Permits, Approvals and Inspections (PAI)  inspects new construction for the presence of working carbon monoxide alarms.

CO Alarms and Rental Properties

In April 2018, Maryland legislation went into effect requiring rental units to have carbon monoxide alarms installed on every level of the unit, including the basement.

The law applies to dwellings that contain one or more of the following: fuel-burning equipment, an attached garage and wood-burning fireplaces or pellet stoves.

The CO alarms must be installed in one of the following ways:

  • Hardwired into an alternating current power line with secondary battery backup
  • Battery-powered, sealed, tamper-resistant and using a battery with a life of at least 10 years
  • Through a security system, i.e., connected to an on-site control unit that monitors the CO alarm remotely and alerts a responsible party when the device sounds an alarm
  • Combined with a hard-wired smoke alarm, if the combined device complies with Underwriters Laboratories (UL) and American National Standards Institute (ANSI) standards

The law also requires owners to provide written information on alarm testing and maintenance to at least one adult occupant of the unit, to maintain records of notification, and to install alarms for hearing-impaired residents if a hearing-impaired person lives in the unit.

The CO law is enforced by the County's Code Enforcement Bureau.

One- and Two-Family Homes

The 2009 International Residential Code adopted by Baltimore County and effective July 1, 2010 requires that an approved CO alarm be installed outside of each sleeping area in the immediate vicinity of bedrooms in the following:

  • Newly constructed one- and two-family dwelling units
  • Existing one- and two-family dwellings where work requiring a building permit occurs if a fuel-fired appliance is installed in the home or if the home has an attached garage

Response to a CO Emergency

Firefighters and EMS personnel respond to 911 calls involving sounding CO detectors and illness involving suspected CO exposure. Typically, they will:

  • Use gas meters to monitor the presence of CO and evacuate the building if the readings show the building is unsafe.
  • Ventilate the building.
  • Locate the source of the CO and take immediate steps to stop the leak/buildup, usually by shutting down the appliance that is causing the CO buildup.
  • Contact BGE, if necessary.
  • Monitor, treat and transport patients affected by CO.
  • In cases involving rental units, fire officials will contact the Building Inspections Bureau, Department of PAI, for calls involving more than 50 ppm of CO. The Department of PAI will ensure that any necessary work is properly permitted and performed by a qualified, licensed contractor.

Education and Prevention

Prevention is the key to avoiding problems associated with CO. Educate yourself about carbon monoxide—what causes it, the symptoms of CO poisoning, how to install detectors. The Fire Department's fact sheet and the National Fire Protection Association's website regarding CO are helpful resources.

Consider asking a Fire Department representative to visit your community group to discuss this important home safety issue.

Revised January 3, 2020         


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