5 Dangerous Household Gases and How to Detect Them
Everything from the newly painted bathroom to a drafty basement could be affecting our home's air quality
![A living room with a large window and a fireplace](https://media.angi.com/s3fs-public/living-room-large-window-fireplace.jpeg?impolicy=leadImage)
![A living room with a large window and a fireplace](https://media.angi.com/s3fs-public/living-room-large-window-fireplace.jpeg?impolicy=leadImage)
When you think about it, our homes are a bit like complex, well-oiled machines. Everything from the HVAC system to the foundation and walls work together to keep us comfortable and cozy. But just like any great machine, caring for it is key—especially when its parts produce potentially harmful chemicals and gases. Here are five dangerous household gases to keep on your radar when maintaining a safe home.
1. Carbon Monoxide
Carbon monoxide—or “CO” for short—can come from many of the appliances and machines in or around our home that burn fuel. The most common include:
Fireplaces and woodstoves
Furnaces
Grills
Automobiles
Water heaters
Space heaters
Dryers
Ovens and stoves
When not properly ventilated, CO poisoning can lead to flu-like symptoms that are hard to pin down until they become serious. Sadly, over 400 people die each year from CO over-exposure, according to the University of Iowa Hospitals and Clinics. In other words, we need to keep the threat of CO at the top of our homeowner list.
How to Lower Your Exposure
While there are many ways to keep CO exposure at bay, the key is ventilation and upkeep. Appliances, fireplaces, and cars should never send CO streaming into your home if they and their ventilation system are in working order. The Environmental Protection Agency (EPA) recommends:
Ensuring your gas-run appliances are running properly (oven, stove, dryer, etc.)
Using exhaust fans above cooking areas
Ventilating your flue and chimney when in use
Scheduling a regular furnace inspection
Never idling the car in an unventilated garage
There are a few pros to keeping on speed dial for annual inspections, such as your local HVAC team, a chimney sweep near you, and local plumbers with gas repair experience.
How to Check Your Home
Carbon monoxide has no odor, so you won’t be able to detect it by smell. It’s important to install carbon monoxide detectors on each level of your home, especially outside sleeping areas. Be sure to regularly check their battery power.
2. Formaldehyde
We might associate formaldehyde with some rather macabre uses, but in reality, this common chemical pops up in everything from particle board and flooring to fuel-dependent appliances. Much like carbon monoxide, you won't smell formaldehyde, even when it's in your home in higher doses.
According to the EPA, most homes have far below 0.1 parts per million presence—an amount typically considered nothing to worry about. Rise above this rate, however, and sensitive people (such as those with asthma) could experience burning eyes, breathing problems, skin rashes, and even more severe allergic reactions.
How to Lower Your Exposure
Common carriers of formaldehyde include different varieties of pressed wood and plastic. It is often used in the adhesive of these products as well. You may also find formaldehyde in laminate flooring. The EPA recommends double-checking products for formaldehyde levels and opting for exterior-grade wood products that use alternate resins.
Ventilation through the window and exhaust fans are ideal, especially if you've just had the floors done or purchased a product that needs to off-gas. If you have a smoker in the house—another source of formaldehyde—request they smoke outside to avoid exposure.
It's important to note that formaldehyde is one of the most common forms of VOCs—or volatile organic compounds—in our homes. You'll find VOCs in paint, cleaning supplies, pesticides, and building materials.
How to Check Your Home
If you're concerned about long-term exposure to formaldehyde, you can order test kits online or hire a home air quality specialist near you.
3. Radon
Radon naturally occurs in the ground, which can be a real problem for homeowners. Radon is the second-leading cause of lung cancer and the most common way we're exposed to radiation, according to the EPA.
Foundations can allow radon to seep into our homes over time. Anything over 4 picocuries per liter measured inside legally requires radon mitigation.
How to Lower Your Exposure
If you don't have one already, make sure you have an excellent radon mitigation system in place in your home. Depending on your home's foundation, a radon specialist and foundation team may choose to:
Seal spaces between your flooring and foundation that allow radon seepage
Add a plastic and aggregate layer beneath your home to contain radon
Set up a ventilation system to remove radon from beneath your home
The average cost of a radon mitigation system is $1,000, depending on the extent of necessary changes to your home.
How to Check Your Home
You can either request a one-time radon test or set up long-term radon detection in problem areas like your basement. You may be required to test your home for radon levels when selling it as well.
4. VOCs
![A woman in protective gloves cleaning using a spray detergent](https://media.angi.com/s3fs-public/woman-gloves-cleaning-spray-detergent.jpeg?impolicy=leadImage)
As mentioned, volatile organic compounds (or VOCs) make their way into many parts of our homes. While formaldehyde is a major culprit, you'll also find chemicals that emit gas, including:
Tetrachloroethylene often used in dry cleaning
Benzene makes its way into everything from detergents to nylon materials
Ethylene glycol in cosmetics, plastic, and ink
Xylene, which is used as a solvent
The tricky thing about avoiding VOCs altogether is their prevalence. You’ll encounter them in cleaning supplies, common decor items and clothing, and even craft glue.
According to the EPA, the health dangers of VOCs greatly depend on the amount of exposure and ventilation. In some cases, you'll see no symptoms or long-term health effects. In more serious cases, VOCs can lead to breathing issues, eye and skin irritation, and even liver or nervous system damage.
How to Lower Your Exposure
When painting or cleaning your home, always use a proper ventilation system and protective equipment. When you're finished with these products, be sure to store them properly—especially unsealed cans of paints in unventilated areas.
Whenever possible, opt for products certified to use low VOCs such as specialized paints and cleaning products. The EPA also recommends integrated pest management over using chemical pesticides indoors.
How to Check Your Home
Detecting such a large number of chemicals is best when working with a professional air quality control specialist. The best protection against the wide range of VOCs is cutting down on products with high levels of these chemicals and increasing ventilation in your home.
5. Nitrogen Dioxide
Nitrogen dioxide is a toxic and corrosive gas that can enter your home from a number of sources. Like formaldehyde, nitrogen dioxide lurks within cigarettes, so homes with smokers are at a higher risk. Other sources of nitrogen dioxide (NO2) include unvented combustion appliances, vented appliances that have been incorrectly installed, and kerosene heaters.
Nitrogen dioxide can lead to a number of health issues. In small doses, it can irritate your eyes, throat, nose, and entire respiratory tract. If you are exposed to it long-term, you could develop acute or chronic bronchitis. Those who already suffer from breathing issues, including those with asthma and allergies, can be more significantly affected.
How to Lower Your Exposure
To keep your exposure to NO2 low, make sure all smokers take their cigarettes outside. Invest in vented gas appliances, and always hire a local appliance installation company when connecting any new vented gas appliances to ensure proper installation.
How to Check Your Home
If you’re not sure if you and your family are being exposed to nitrogen dioxide, you can purchase a gas detection kit, which will find not only NO2 but also other dangerous household gases. You can also have an appliance technician ensure your gas appliances are properly installed and ventilated.
Check in with a Pro if You Suspect Something Is Wrong
Dangerous household gases are no small matter—and acting fast is crucial for your health. If you suspect there’s some kind of hazardous gas leak within your home, get you, your family, and your pets outside as quickly as possible.
Then call a trusted gas leak professional or gas appliance repair company near you to visit your home, test for hazardous gases, and repair the source of the issue.