According to the CDC more than 400 people die in the U.S. from accidental carbon monoxide (CO) poisoning yearly. In 2021, over 300 MA residents visited the emergency department (ED) due to accidental CO poisoning. Massachusetts has one of lowest mortality rates from CO poisoning. However, within the last ten years, there has been an overall increase.
Massachusetts is one of few states that require CO detectors in every home. On March 21, 2006, Nicole’s Law went into effect. Nicole's law requires CO detectors in all Massachusetts homes with potential sources of CO. The law also sets requirements for the type, location, maintenance, and inspection of CO alarms.
You can use the display to review unintentional CO poisoning hospitalization or ED rates for any city or town in Massachusetts.
What Is carbon monoxide?
Carbon monoxide (CO) is a colorless, odorless, poisonous gas, that can cause sudden illness and death. It claims the lives of hundreds of people every year and makes thousands more ill. It is a toxic gas released from appliances and equipment that burn fossil fuels.
Common sources of exposure include:
Cars
Gas and wood stoves
Clogged chimneys
Unvented kerosene or gas space heaters
Gas water heaters
Gas or oil furnaces
Portable generators
Lawn mowers
What are symptoms of CO poisoning?
CO poisoning results in a range of symptoms from mild to severe, including death. If you or someone you are around has these symptoms, move immediately to fresh air. Call 911 or another local emergency number for medical assistance.
The most common symptoms of CO poisoning are:
- Headache
- Dizziness
- Weakness
- Nausea or vomiting
- Trouble thinking
During prolonged exposure or at very high levels, CO can cause loss of consciousness and death.
It is important to note that these symptoms can also point to other illnesses. If a patient complains of those symptoms, but does not have a fever, CO poisoning should be considered and a detailed history of exposure to CO sources should be taken.
What are the sources of CO?
You may be exposed to unsafe levels of CO from:
- Poorly maintained or unvented heating equipment
- Furnaces and water heaters
- Using a gas stove, oven, or grill to heat the
- Clogged chimneys or blocked heating exhaust vents
- Snow blocked vents and car pipes
- Running motor vehicles indoors (e.g., in garages or other enclosed spaces)
- Operating generators or gas-powered tools indoors or outside near windows, doors or intake vents
- House or building fires.
- Cooking with a charcoal or gas grill inside the home or other enclosure
- Using a propane camp stove, heater, or light inside a tent
- Engaging in activities near motor vehicle engine exhaust outlets, including boats
CO poisoning during winter months
- In the Northern region of the U.S. most CO poisoning cases occur during winter. Winter weather or power outages can lead to improper use of heating or cooking devices. These devices can cause CO to build up in a home, garage, camper, and to poison the people and animals inside.
- Except for space heaters, none of these devices should ever be used inside the home, basement, garage, camper, tent or outside near an open window.
Who is at risk for CO poisoning?
Health
Everyone is at risk of CO poisoning. People living with chronic heart disease, anemia, and respiratory problems can be affected by CO poisoning faster than others and may be the first to show symptoms. CO poisoning can also be dangerous to unborn children increasing the risk of developmental disorders and fetal death.
Age
Infants and children have an increased vulnerability to carbon monoxide due to their size. Children left in cars may be at risk of CO poisoning, especially in the winter months when snow can block the car’s tailpipe. If you are a caregiver, have your child wait outside the car while you shovel snow.
Older adults also often have health conditions that can increase the risk of fatal exposure. Learn more about preventing carbon monoxide poisoning using the EPA’s Preventing carbon monoxide poisoning for older adults.
Environment
Extreme weather due to climate change may cause more flooding and power outages. This can lead to increased use of portable generators or alternate heating sources inside. Carbon monoxide poisoning from improper use of items such as using charcoal or grills inside, results in hundreds of deaths and thousands of illnesses each year.
Social determinants of health
Our health is impacted by the social determinants of health (SDoH). These are the social, economic, and physical factors where we work, live and play.
Community investments in infrastructure can affect people’s likelihood for experiencing CO poisoning. Areas with higher income often have a greater investment in the electric grid. Areas with powerlines below ground are less likely to have power outages and outages that last a long time. Areas with more trees and poorer housing quality are more likely to have longer power outages or issues with heating.
People who cannot afford to heat their homes, rent, or are experiencing power outages may turn to non-conventional heating sources. This can lead to increased carbon monoxide poisoning. If you are a landlord, ensure that the heating systems, chimneys, and gas lines in your properties are properly maintained. Also, be sure to check for proper ventilation.
Learn about carbon monoxide poisoning by visiting CDC’s Carbon Monoxide Poisoning page.
How can you prevent CO poisoning?
The release of CO is almost entirely preventable. To prevent CO release, make sure devices that may emit the gas are correctly installed. Take time to perform maintenance. Make sure the device is operating correctly. CO poisoning can also be prevented with carbon monoxide detectors. These are also called carbon monoxide alarms. CO detectors are legally required in all Massachusetts' homes with potential sources of CO.
Some steps you can take to reduce your exposure are:
- Install a carbon monoxide alarm in the hallway near every sleeping area in the home.
- Do not heat your home with a gas oven.
- Do not use a generator, charcoal grill, camp stove, or other gasoline or charcoal-burning device inside your home, basement, or garage or near a window.
- Service heating systems, water heaters, and any other gas, oil, or coal burning appliances by a qualified technician every year.
- Call a service expert to see if an odor from a gas refrigerator's cooling unit is detected. While CO has no odor itself, it could mean there is a defect in the cooling unit which could be giving off CO.
- Buy gas equipment carrying the seal of a national testing agency, such as the American Gas Association or Underwriters' Laboratories.
- Check that fuel-burning appliances are properly installed and vented.
- Check and clean chimneys every year to be sure they are not blocked by debris.
- Assure idling cars are properly vented, especially in snow.
For more prevention tips, visit CDC’s CO Prevention Guidelines and EPA’s Preventing Carbon Monoxide Poisoning in Older Adults factsheet.
Why does MA EPHT track CO poisoning?
We track unintentional CO poisoning to support public health prevention and interventions. CO poisoning data can provide information on when exposures occur. For example, spikes in CO poisoning can happen after disasters and storms. This is often due to increased generator use.
Available data
Use the Explore CO Poisoning Data link on this page to access the following measures:
- Annual number of hospitalizations / ED visits
- Annual crude rate per 100,000 population
- Annual age-adjusted rate per 100,000 population
- Explore data in tables, charts, and maps
MA EPHT presents case counts and crude rates on CO poisoning emergency department and hospital admissions for the following geographies: city/town, county, EP region, EOHHS region, and statewide. Measures are offered by a combination of year, age group, and sex. The most current available data is shown. Be sure to check the site periodically as new data is added each year. To protect privacy, no information is shown that could identify an individual.
For more information on this dataset, visit the MA EPHT Metadata webpage.
Additional resources
Massachusetts
- MA Department of Fire Services Carbon Monoxide (CO) Safety: General information about carbon monoxide, including safety guides offered in English and Spanish.
- MA Department of Fire Services Smoke and Carbon Monoxide Alarms: A quick guide to carbon monoxide and fire alarms, as well as safety guides offered in English and Spanish.
- MA Department of Fire Services Preparing Your Home for a Smoke and CO Alarm Inspection: Information for those looking to sell their home to ensure the carbon monoxide and fire alarms meet the inspection standard for sale or transfer.
- Massachusetts Law on Carbon Monoxide Detectors: A list of Massachusetts’ regulations related to carbon monoxide and carbon monoxide alarms.
National
- CDC Carbon Monoxide Poisoning Basics: Information on carbon monoxide from the CDC
- EPA Carbon Monoxide’s Impact on Indoor Air Quality: Information from U.S. EPA on carbon monoxide's impact on indoor air quality.