HUD Updates Guidance Related to Carbon Monoxide

Carbon monoxide protections in assisted housing will be enforced.


HUD issued Notice H-2022-01 on Jan. 31 to clarify federal requirements for carbon monoxide (CO) alarms and detectors. CO is a byproduct of fuel-fired combustion appliances such as furnaces and water heaters. And if not properly vented, this undetectable gas can be dangerous and even deadly.

Carbon monoxide protections in assisted housing will be enforced.


HUD issued Notice H-2022-01 on Jan. 31 to clarify federal requirements for carbon monoxide (CO) alarms and detectors. CO is a byproduct of fuel-fired combustion appliances such as furnaces and water heaters. And if not properly vented, this undetectable gas can be dangerous and even deadly.

In 2019, HUD came under increasing pressure to act following reports of CO poisoning among residents of HUD housing, which has led to at least 11 deaths since 2003. Housing advocates and public health experts have suggested that in spite of the clear dangers of CO poisoning, HUD has been slow to provide protections for these families.

HUD’s Office of Lead Hazard Control and Healthy Homes (OLHCHH) has warned about the dangers of CO as a poisonous gas that can be fatal at high levels of exposure for decades. But, at the time, HUD had yet to require the use of CO monitors in all of its housing programs. In fact, in 2019, HUD issued a notice reminding owners of their legal obligation to install working CO detectors in those jurisdictions where these devices are required. But in those states and local communities where CO detectors aren’t required, HUD merely strongly encouraged housing authorities and owners to install them.

Now, the HUD Offices of Public and Indian Housing (PIH), Housing, and OLHCHH issued the Jan. 31 notice to remind affected parties of the CO requirements included in the Consolidated Appropriations Act of 2021. This law requires sites to meet certain requirements within two years of its enactment, which was Dec. 27, 2020. As a result of the law, public housing agencies and authorities (PHAs), and site owners that receive federal rental assistance must comply with the International Fire Code (IFC) 2018 standards on the installation of CO alarms or detectors by Dec. 27, 2022.

We’ll cover the requirements of when, where, and how owners must install and maintain CO detectors.

Deadline and Applicability

HUD has been making efforts to improve safety conditions in assisted housing. This notice follows a tragic season of fire damage in HUD-assisted sites that have resulted in death and injury among residents. The dangers highlighted in this notice are longstanding safety problems.

CO is an odorless, colorless, and toxic gas. It is an invisible and tasteless gas produced by incomplete combustion of fuel burned in vehicles, small engines, stoves, lanterns, grills, fireplaces, gas ranges, or furnaces. It can build up indoors and poison people and animals who breathe the toxic fumes. The effects of CO exposure can vary from person to person depending on age, overall health, and the concentration and length of exposure. Exposure can cause harmful health conditions, permanent brain damage, life-threatening cardiac complications, fetal death or miscarriage, and death in a matter of minutes. Individuals who are asleep or intoxicated may die from CO poisoning before experiencing any symptoms.

The notice reminds owners of their important role to prevent potential loss of life and severe injury associated with CO in housing they own or manage. HUD points out that “CO poisoning is an important safety issue for families in assisted housing...each year, more than 400 Americans die from unintentional CO poisoning not linked to fires, more than 20,000 visit the emergency room, and more than 4,000 are hospitalized.”

Although HUD encourages sites to install CO alarms and detectors that meet the appropriate standards as soon as possible for the health and safety of residents, the requirement imposed by law will be enforced beginning with the effective date of Dec. 27, 2022. The new requirement applies to all Housing Choice Voucher units and all Public Housing, Project Based Voucher, Project Based Rental Assistance, Section 202, and Section 811 properties with fire-fueled or fire-burning appliances or an attached garage.

International Fire Code Standards

HUD has adopted the CO safety standards of the IFC 2018. The IFC establishes minimum requirements for CO protections, which are periodically updated. HUD says all sites must have CO detectors installed in all dwelling units that meet or exceed the standards in Chapters 9, Fire Protection and Life Safety Systems, and Chapter 11, Construction Requirements for Existing Buildings, of the IFC. It’s important to note that owners should follow local codes and adopt whichever standard is more stringent.

According to HUD, CO alarms or detectors that meet or exceed IFC standards must be installed in each dwelling unit that received tenant- or project-based rental assistance. The IFC defines CO alarms and detectors as follows:

  • Carbon Monoxide Alarm: A single or multiple station alarm intended to detect carbon monoxide gas and alert occupants by a distinct audible signal. It incorporates a sensor, control components, and an alarm notification appliance in a single unit.
  • Carbon Monoxide Detector: A device with an integral sensor to detect carbon monoxide gas and transmit an alarm signal to a connected alarm control unit.

Hard-wire requirements. According to the IFC, CO alarms must receive their primary power from the building’s permanent wiring without a disconnecting switch other than that required for overcurrent protection, and when the primary power service is interrupted, serviced by a battery [Section 915.4.1, Power Source]. In other words, CO alarms or detectors need to be hard-wired and have a battery backup.

UL rating requirements. UL is otherwise known as Underwriters Laboratories, a third-party certification company and safety organization that sets industry-wide standards on products. The IFC says CO alarms must meet the UL 2034 standard for sensitivity [Section 915.4.2, Listings]. And combination CO/smoke alarms are an acceptable alternative to CO alarms. These must be designated to have UL 2034 and UL 217 standards for sensitivity [Section 915.4.4, Combination alarms].

Installation locations. Section 915 and Section 1103.9 of the IFC describe the situations when a CO detector or alarm is required in units and buildings. Here are the requirements for building designs typically found in HUD-assisted housing:

  • “Carbon Monoxide Detection shall be installed in dwelling units that contain a fuel-burning appliance or fuel-burning fireplace” [IFC – Chapter 9, Section 915.1.2 – Locations].
  • “Carbon Monoxide detection shall be included in any dwelling units with attached private garages” [IFC, Chapter 9, Section 915.1.5 Private Garages].
  • “Carbon Monoxide detectors shall be installed in dwelling units outside each sleeping area and in the immediate vicinity of the bedroom. If a fuel-burning appliance is installed in the bedroom, a CO detector must be installed in the bedroom” [Section 915.2.1].

Fuel-burning appliances emit CO as a byproduct of the combustion of coal, kerosene, oil, wood, fuel gases, or other petroleum or hydrocarbon products. These can include gas/fuel-fired ranges, stoves, fireplaces, clothes dryers, furnaces, air handlers, boilers, and water heaters.

Exceptions. According to the IFC, CO detection isn’t required in dwelling units that don’t have openings between the fuel-burning appliance or underground garage and the dwelling unit [Section 915.1.4, Fuel Burning Appliance outside of dwelling units]. This means that if you have a central heating or hot water system that doesn’t distribute heat via forced hot air, CO detection isn’t specifically required in the dwelling units. Or it may be the case that a CO detector is installed in required locations between the fuel-burning appliance and the dwelling units. In this case, you would have to have CO detection between a boiler or water heater and a dwelling unit in the mechanical rooms, and any garages.

Eligible Expenses

According to the notice, PHAs operating public housing units may use either operating funds or capital funds for purchase, installation, and maintenance of CO alarms or detectors. Based on the law’s set-asides, the capital fund program conducts competitions for additional funds for CO alarms or detectors.

For the HCV and project-based voucher programs, the property owner or landlord is responsible for the cost of CO alarms or detectors.

Owners of properties receiving assistance through the project-based rental assistance, Section 202, and/or Section 811 program may utilize the property’s reserve for replacement account, residual receipts, general operating reserves, owner contributions, or secondary financing to fund the purchase, installation, and maintenance of CO alarms and detectors. These expenditures may be subject to a standard approval process where applicable, but the purchase, installation, and maintenance of CO alarms and detectors are deemed eligible expenses.

Carbon Monoxide Prevention Strategies

and Resident Education

HUD’s notice encourages owners to inform residents of CO risks and provide examples of CO avoidance. The notice also states that HUD will develop additional CO materials for property management to support educational activities.

While CO protection devices are important to prevent CO poisoning, preventing CO intrusion in the first place is the best defense against CO poisoning. Here are important reminders with regard to CO intrusion and actions when CO alarm sounds.


  • Make sure appliances are installed and operated according to the manufacturer’s instructions and local building codes. Most appliances should be installed by qualified professionals. Have the heating system professionally inspected and serviced annually to ensure proper operation. The inspector should also check chimneys and flues for blockages, corrosion, partial and complete disconnections, and loose connections.
  • Never service fuel-burning appliances without proper knowledge, skill, and tools. Always refer to the owner’s manual when performing minor adjustments or servicing fuel-burning equipment.
  • Never operate a portable generator or any other gasoline engine-powered tool either in or near an enclosed space such as a garage, house, or other building. Even with open doors and windows, these spaces can trap CO and allow it to quickly build to lethal levels.
  • Install a CO alarm that meets the requirements of the current UL 2034 safety standard. A CO alarm can provide some added protection, but it is no substitute for proper use and upkeep of appliances that can produce CO. Make sure the alarm cannot be covered up by furniture or draperies.
  • Never use portable fuel-burning camping equipment inside a home, garage, vehicle, or tent unless it is specifically designed for use in an enclosed space and provides instructions for safe use in an enclosed area.
  • Never burn charcoal inside a home, garage, vehicle, or tent.
  • Never leave a car running in an attached garage, even with the garage door open.
  • Never use gas appliances such as ranges, ovens, or clothes dryers to heat your home.
  • Never operate unvented fuel-burning appliances in any room where people are sleeping.
  • Do not cover the bottom of natural gas or propane ovens with aluminum foil. Doing so blocks the combustion air flow through the appliance and can produce CO.
  • Provide regular resident CO education through policies or signage.


  • Never ignore an alarming CO alarm! It is warning you of a potentially deadly hazard.
  • If the alarm signal sounds do not try to find the source of the CO, immediately move outside to fresh air and call your emergency services, fire department, or 911.
  • After calling 911, do a head count to check that all persons are accounted for. Do not reenter the premises until the emergency services responders have given you permission. You could lose consciousness and die if you go in the home.
  • If the source of the CO is determined to be a malfunctioning appliance, do not operate that appliance until it has been properly serviced by trained personnel.
  • If authorities allow you to return to your home, and your alarm reactivates within a 24-hour period, repeat the above steps and call a qualified appliance technician to investigate for sources of CO from all fuel-burning equipment and appliances, and inspect for proper operation of this equipment. If problems are identified during this inspection, have the equipment serviced immediately. Note any combustion equipment not inspected by the technician and consult the manufacturers’ instructions, or contact the manufacturers directly, for more information about CO safety and this equipment. Make sure that motor vehicles are not, and have not been, operating in an attached garage or adjacent to the residence.