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Carbon monoxide safety

Learn how to protect yourself and your family from deadly carbon monoxide poisoning.

Carbon Monoxide (CO) is an invisible, odorless, colorless gas created when fuels such as gasoline, wood, coal, natural gas, propane, oil, and methane burn incompletely. In the home, heating and cooking equipment that burn fuel are possible sources of Carbon Monoxide. Vehicles or generators running in an attached garage can also produce dangerous levels of Carbon Monoxide.

Effects of Carbon Monoxide (CO) Exposure

Carbon Monoxide replaces oxygen in the bloodstream, which leads to suffocation.

  • Mild Exposure - Mild effects include symptoms similar to flu such as headache, nausea, and vomiting.
  • Medium Exposure - More severe symptoms include difficulty breathing, severe headache, drowsiness, confusion, and an increased heart rate.
  • Extreme Exposure - Extreme symptoms can cause unconsciousness, convulsions, cardio respiratory failure, and death.
Massachusetts Law regarding Carbon Monoxide Detectors

In accordance with Massachusetts General Law Chapter 148 Section 26 Fl/2, Massachusetts Fire Prevention Code 527 CMR 1.00 c 13 regulates the placement of CO detection in dwelling units. Regulations apply "to every dwelling, building or structure occupied in whole or in part for residential purposes, that:

  • contains fossil fuel burning equipment, or
  • incorporates enclosed parking within its structure."

In summary, effective March 31, 2006, the regulation applies to dwellings; buildings or structures occupied in whole or in part for residential purposes that contain fossil fuel burning equipment or has enclosed parking. The owner, landlord or superintendent shall equip these dwelling buildings or structures with working listed carbon monoxide alarms.


The carbon monoxide alarm shall be located in each level of a dwelling unit including finished basements and cellars but not including crawl spaces and uninhabitable attics. (Check manufacturer's requirements for installation instructions.) The types of carbon monoxide detectors allowed are:

  • battery-operated
  • plug in with battery back up
  • hard-wired with battery back up
  • low voltage or wireless, or
  • a combination smoke and carbon monoxide alarms/detectors. Note that these are required to be photoelectric smoke detectors if located within 20 feet of a kitchen or bathroom.

Purchase only alarms listed by a qualified independent testing laboratory meeting the requirements of IAS/CAS 6.19 or UL 2034. Install, test, and maintain CO alarms as specified by the manufacturer's instructions.

In compliance with Massachusetts State Law (527 CMR 1.00 c 13), a carbon monoxide alarm shall be installed in the immediate vicinity of the sleeping area, not to exceed 10 feet in any direction from any bedroom door.

Call the Boston Fire Department at 911 if your carbon monoxide alarm sounds. Replace the battery per the manufacturer's instructions. The Boston Fire Department recommends twice a year when you change your clocks.

Alternative Compliance Option

Large buildings with multiple dwelling units that contain minimal or no sources of carbon monoxide inside the individual units are required to install hard-wired detectors. These buildings may provide protection in the following areas of the structure:

  1. Areas or rooms containing centralized fossil fuel burning equipment such as boiler rooms, hot water heaters, central laundry areas and all adjacent spaces.
  2. Adjacent spaces of enclosed parking.
Safety Checklist

Carbon monoxide alarms are not substitutes for smoke alarms. Make sure the dwelling has working smoke alarms that are located in accordance with the minimum required locations. It is recommended that working smoke detectors be located on every level and directly inside all sleeping rooms.

Make sure carbon monoxide and smoke alarms are tested regularly. Know the difference between the sound of smoke alarms and carbon monoxide alarms. Have an escape plan for emergencies and practice the plan with all members of the dwelling (household) regularly, at least twice a year.

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