Home Safety Tips: Identifying and Minimizing Common Causes of Carbon Monoxide Poisoning

Carbon monoxide is a deadly poison that people may not even realize is a problem until they are too sick to know how to fix it. Unlike natural gas, it is colorless, odorless, and does not create any sound when it escapes into a home. This compound arises through the combustion process, particularly when people use fuel to create heat to run appliances or warm the home.

Preventing carbon monoxide buildup requires an understanding of the systems that can create it. With this information, homeowners will know the most common carbon monoxide sources and how to reduce their risk.

Furnaces & Chimneys

Most homes have a furnace to provide central heating. Because most furnaces use natural gas to produce heat for the home, carbon monoxide can be a risk.

Furnaces should prevent the accumulation of carbon monoxide in the home. The furnace uses a heat exchanger to convert fuel into usable heat. Over time, and without regular maintenance, the heat exchanger can become cracked or dirty. At this point, it might leak carbon monoxide into the house.

Homeowners may also need to pay attention to the vent apparatus for the furnace. Most furnaces vent directly outside the home through a vent stack leading to a main roof vent or chimney. If the vent stack is not installed properly, the burning process's byproduct can push carbon monoxide back down. If the chimney is damaged, cracked, or blocked with debris, it can prevent the gases from venting outside. The best way to prevent any of these things from happening is to schedule regular maintenance for the furnace and confirm the vent stack and chimney are in good condition.

Gas Space Heaters

Many people use space heaters to augment their home’s heating system or provide heat for buildings that lack a central heating arrangement. Space heaters can run off electricity or gas. When used inside, gas space heaters can contribute to carbon monoxide buildup. Newer space heaters may have a sensor that shuts down the machine when the space's oxygen drops below a certain level. Older machines may not have these sensors.

Experts recommend that people only use gas heaters in well-ventilated places. A garage with an open door may not provide sufficient ventilation. Running a space heater should only be done under careful supervision, and especially not while people are sleeping. Alternatives with better ventilation may be preferable if people can use those instead. Homeowners who must use these systems should install a carbon monoxide detector.

Automobile Exhaust

Vehicles that use gasoline produce exhaust that is usually vented out of a tailpipe. The vent's condition and the car's location can affect people’s risk of carbon monoxide exposure. Some people choose to turn on their cars in cold weather and warm them up from inside a closed garage before they leave. This can cause a deadly carbon monoxide buildup in the garage, potentially spreading into the home.

A faulty exhaust system may also cause carbon monoxide exposure. A broken tailpipe may not vent properly, leading the exhaust to pour inside the vehicle's cabin. If people are caught in a snowstorm and running their cars for warmth, a blocked tailpipe can create the same problem. The best solution is to maintain the vehicle regularly, test emissions, and avoid using it in an enclosed space.

Gas Stoves and Ovens

Gas stoves and ovens can provide heat for cooking and baking, so it is not surprising that homeowners may use them to supplement home heating as well. Unfortunately, the ventilation for kitchen appliances is often subpar and much lower in efficacy than ventilation for a furnace or boiler. As such, the concentration of carbon monoxide may be much higher in the kitchen than in other rooms of the home. Running the oven for long periods of time or daily can make the problem worse.

Homeowners can avoid the worst problems related to a gas range if they use ventilation. In some cases, particularly for people who plan to use the range for hours each day, increasing the ventilation level can improve the situation. However, having a ventilation system is only useful if homeowners are willing to use it. Ventilation should be present during all cooking endeavors and for some time afterward. Additionally, people should avoid using the range to provide additional heat in the home. Leaving an oven door open while it is running can increase carbon monoxide buildup as well.

Dryers

Carbon monoxide needs two things to accumulate, and dryers may provide both: a fuel-burning heat source and an enclosed space with limited oxygen. Dryers have vents that usually lead outside the home to lower the likelihood that something could ignite inside. This is true for dryers that run on electricity or gas. Gas dryers need adequate ventilation to prevent carbon monoxide. When there is not enough oxygen for combustion, the result is carbon monoxide.

Homeowners may be surprised how easily carbon monoxide can become a problem with gas dryers. Vents that are not cleaned regularly can get clogged with lint or other debris. Unfortunately, this is the perfect material to start a fire with sufficient heat and friction. People should plan to clear out the lint trap with each use, ensure the vent is clear from the outside, and schedule service once every year or two.

Generators

Many homeowners use generators to provide auxiliary power for outdoor activities or during a power outage. The convenience of a generator gives people access to energy they can use to run tools and appliances without needing active electrical power. However, unsafe use of generators can cause carbon monoxide poisoning. Most generators run on a fuel source like gasoline or propane. When burning these fuels, generators produce exhaust that contains carbon monoxide.

People may think running the generator near the home or in the garage is safe, but it is not. Experts recommend that homeowners operate generators at least 10 feet away from the home and direct exhaust so that it flows away from the property, not towards it. Some generators have built-in oxygen sensors to determine if the buildup of carbon monoxide is too high. People should also keep a carbon monoxide detector inside their home, especially while the generator is used.

Fireplaces

Ensuring that a fireplace does not release carbon monoxide into the home requires care at the source of the fire and the ventilation system. Homeowners may choose to start a fire in a designated fireplace or a wood-burning stove. They should only operate these systems while the fireplace damper is open and the chimney is clear. Periodically, people should ensure that their gas-burning fireplace has a properly functioning valve. A full ash bucket or fireplace with debris can also lead to carbon monoxide accumulation.

In an ideal situation, the chimney will vent the smoke and other fuel byproducts out of the home safely. If the chimney is blocked with soot or creosote or the fireplace damper is closed too early, it will send the smoke and exhaust into the home. To minimize risk, homeowners may want to install a carbon monoxide detector in a nearby room and avoid running the fireplace overnight.

Grills

Given that any heat source that uses fuel can produce carbon monoxide, grills and other equipment that produce heat for outdoor use should never be brought inside. Even homes with excellent ventilation can have difficulty eliminating carbon monoxide, and homeowners may not know there is an issue until they are in danger. Grills that run on propane or natural gas emit byproducts, including carbon monoxide. Charcoal grills can produce the same, even those that are rated safe for indoor use. People should avoid grilling close to an open door because the exhaust can float indoors and be difficult to remove. The safest way to operate this equipment is to identify a spot several feet away from an exterior door or an open window.

How to Prevent Carbon Monoxide in the Home

The best way to minimize the risk of carbon monoxide buildup is to prevent carbon monoxide from entering the home in the first place. Once homeowners understand how to evaluate the most common carbon monoxide sources, they can use their equipment correctly and keep tools in their proper places.

Install Carbon Monoxide Detectors

Installing carbon monoxide detectors and maintaining them regularly is a simple way to reduce the risk of carbon monoxide poisoning. Homeowners may not be aware that common smoke detectors do not raise an alert due to high carbon monoxide levels. They will need a separate detector, which is a different device. Carbon monoxide detectors can be installed in similar places to smoke detectors. People should keep the detectors at least five feet off the ground and more than a few feet from fuel-burning equipment like a gas range or a fireplace.

Because carbon monoxide detectors are pieces of equipment that can occasionally have faults, homeowners should test them at least once a month by following the manufacturer's instructions and going through the program. The alarm should be loud enough that people can hear it anywhere inside the home. Experts recommend installing at least one on each floor of the home and more if one floor is large. People should never attempt to trigger the alarm by releasing exhaust in the home as a test. This can cause immediate health effects and may not be enough to determine accurate function.

Have Furnace Inspected Every Year

A gas furnace requires an annual inspection, usually in the fall. While homeowners can schedule maintenance with a professional or perform these tasks by themselves, they may not have the incentive to do so until the furnace starts to show signs of problems. Unfortunately, furnaces can have issues that could lead to a release of carbon monoxide without necessarily showing signs that they will do so. A professional inspection can help identify these concerns.

A furnace inspection takes about an hour and involves several steps, including:

• Changing out the air filter
• Testing the thermostat for proper function
• Inspecting the ventilation apparatus for the furnace
• Looking at the individual parts for wear, like the burner or heat exchanger
• Checking the fuel valve to ensure that it opens and closes correctly

Typically, homeowners should leave at least two feet of room on any side of the furnace for proper airflow. Any less than this could cause a backdraft, depending on the type of combustion system. At the end of the inspection, homeowners can ask questions about the furnace's operation or the proper use of a carbon monoxide detector.

Avoid Backdrafting

The ventilation system for any fuel-burning appliance is crucial. Without it, homeowners may have to deal with a potentially deadly backdraft into the home. The way to determine the condition of the ventilation system is simple. People can take a lit match and hold it near the flue, away from any gas lines or flammable materials. If the vent pulls the wick towards the flue, the ventilation system is likely working properly. If not, there may be a blockage.

Appliances like a gas-burning furnace, gas water heater, or even a wood-burning fireplace need adequate ventilation. In these cases, the flue should draw the exhaust upward and out of the home. When there is insufficient airflow to maintain the ventilation, such as if boxes surround the furnace, the system may pull air from the flue to create combustion. This triggers a backdraft of exhaust and possible toxins into the home. When homeowners select new equipment, they should ask a professional how this might affect their ventilation needs and make changes as necessary. Sometimes, a minor change to the water heater or furnace's position may render the ventilation system ineffective.

Ensure Chimney Vent Is Properly Placed

To have ideal ventilation in the home, the chimney must be sized correctly and properly placed. Homeowners should have a chimney installed by a professional who understands ventilation needs. This task can be trickier in older homes or houses that are undergoing a significant addition or renovation. The best way to promote ventilation is to install the chimney directly above the heat source. Direct-vent heat sources, like a fireplace or furnace, use air from the outside to create combustion and vent directly out of the roof. With this type of equipment, a backdraft is extremely unlikely.

For other types, the chimney must, at minimum, be large enough to allow exhaust to escape without excessive buildup of creosote. Although chimney placement cannot always be directly above the system, adding too many joints or extenders can increase risk. Once the correct installation is complete, homeowners should plan to inspect the vent once a year. Hiring a professional to confirm good condition and proper flow is important, as the chimney can wear down over time.

What to Do if a Carbon Monoxide Detector Goes Off

Like smoke detectors, carbon monoxide detectors only go off in the presence of the toxin they exist to measure. People may get to the point where they no longer pay attention to a smoke alarm when it goes off while they cook, but they must not do the same for carbon monoxide. They cannot determine if the situation is actually safe because carbon monoxide gives no warning. Instead, the home’s residents should immediately open doors and windows and leave as quickly as possible. Children and pets are more susceptible to the negative effects of carbon monoxide exposure. Calling for emergency response is crucial, as some people may be more affected than others. Experts can assess the situation, determine the likely cause, and fix the problem so that residents can return once it is safe.

Carbon monoxide kills hundreds of people every year. If homeowners know the most common sources, like a furnace, gas range, or fireplace, they could ensure these systems continue to work properly. A little advanced work in prevention could save lives. Knowing how equipment works and the correct ways to use them will teach people to leave fuel-burning tools outdoors and confirm that appliances and ventilation systems are functioning appropriately before using them. These steps can minimize carbon monoxide buildup in the home and help homeowners determine when they may have a problem.

Helpful Resources

• https://www.statesman.com/NEWS/20180108/5-things-you-should-know-about-carbon-monoxide
• https://www.alarmnewengland.com/blog/sources-of-carbon-monoxide-poisoning
• https://www.health.state.mn.us/communities/environment/air/toxins/index.html
• https://www.vivint.com/resources/article/most-common-sources-carbon-monoxide-poisoning
• https://6andfix.com/the-dangers-of-carbon-monoxide-leaks-from-a-furnace/
• https://www.explainthatstuff.com/how-heat-exchangers-work.html
• https://www.co2meter.com/blogs/news/11376733-cabin-fever-it-may-be-your-gas-space-heater
• https://www.treehugger.com/psa-space-heaters-increase-your-risk-co-poisoning-4856450
• https://en.wikipedia.org/wiki/Exhaust_gas#Carbon_dioxide_(CO2)
• https://www.abe.iastate.edu/extension-and-outreach/carbon-monoxide-poisoning-vehicles-aen-208/
• https://homeguides.sfgate.com/gas-oven-give-off-carbon-monoxide-84088.html
• https://danielshvacphiladelphia.com/how-the-stove-and-oven-in-your-home-give-off-high-carbon-monoxide-levels/
• https://www.dr-lint.com/dryer-vent-carbon-monoxide-poisoning/
• http://www.dryerventcleaningwi.com/DryingTimeNews/CarbonMonoxide
• https://safedryervent.com/articles/how-safe-is-your-laundry-room/
• https://support.firstalert.com/s/article/Cleaning-and-Maintenance-for-Smoke-and-Carbon-Monoxide-Alarms
• https://www.epa.gov/indoor-air-quality-iaq/where-should-i-place-carbon-monoxide-detector
• https://www.familyhandyman.com/article/what-is-backdraft-in-your-home-and-how-to-stop-it/
• https://www.nachi.org/gas-furnace-inspection-checklist.htm
• https://www.electricgeneratorsdirect.com/stories/7-How-to-Prevent-Carbon-Monoxide-Poisoning.html
• https://www.cdc.gov/co/generatorsafetyfactsheet.html
• https://www.direct-fireplaces.com/resources/fireplaces-carbon-monoxide-what-you-need-to-know/
• https://www.streetdirectory.com/travel_guide/60969/home_security/dangers_brought_about_by_carbon_monoxide_and_fireplaces.html
• https://www.heatnglo.com/ideas/venting-explained
• https://www.northlineexpress.com/help-chimney-proper-venting.html
• https://www.adt.com/resources/carbon-monoxide-detector-beeping