As the climate gets hotter, we’re all starting to grapple with the effects of outdoor air pollution due to smoke, ozone, smog, and other common pollutants. But the air inside your home can be a health hazard too. Indeed, indoor air quality can be anywhere from two to five but up to 100 times worse than outdoor air quality.

While dust, smoke, mold, radon, and volatile organic compounds (VOCs) from building materials and other household items can negatively affect indoor air quality, chemicals released from gas stoves are right there in the mix. The cocktail of compounds gas stoves emit is so significant, in fact, that there’s been government discourse about banning these kitchen appliances over the years.

The appliance is still legal, though, and more than a third of U.S. households have one. So what can you do if you fall into that group? Here, we spoke to experts to better understand which chemicals gas stoves emit, the health concerns linked to those chemicals, and what steps to take to improve your indoor air quality.

What chemicals do gas stoves emit?

The chemicals released from your gas stove are based on the source of the gas. “Most homes with gas appliances burn natural gas supplied by their utility provider. Natural gas is primarily methane and may contain lesser amounts of ethane, propane, butane, carbon dioxide, nitrogen, and hydrogen sulfide,” says Bill Hayes, PE, air quality program coordinator at Boulder County’s Public Health Department.

Because methane is odorless, a chemical called mercaptan is also added to give this gas the pungent, easily recognizable rotten-egg smell to warn residents of a gas leak. “Whatever other contaminants are found in gas piped into our homes, including benzene¹, can also be leaked from gas stoves,” says Rob Jackson, PhD, a climate scientist at Stanford University, and author of the book Into the Clear Blue Sky: The Path to Restoring Our Atmosphere.

“But the pollutants generated during combustion—formed in the flames while stoves are on—are even worse [than the chemicals found in unburned natural gas],” Jackson adds.

Hayes explains that when natural gas is burned⁶², combustion by-products, including nitrogen oxides, carbon monoxide, methane, carbon dioxide, nitrous oxide, volatile organic compounds (like benzene), particulate matter, and trace amounts of sulfur dioxide and formaldehyde, are produced.

“Gas stoves in homes not supplied with natural gas from a utility provider typically burn propane, a by-product of natural gas processing and petroleum refining. Since propane has far fewer impurities than natural gas, its combustion by-products consist of carbon dioxide, carbon monoxide, and water vapor,” Hayes adds.

This means that gas stoves burning propane may pose fewer health risks than those burning natural gas—though the majority of gas stoves in the U.S. use natural gas.

“One of our most surprising findings was that pollutant concentrations we measured from gas and propane stoves lead to dangerous levels for hours even after stoves are off—not just in kitchens but in bedrooms down the hall.” —Rob Jackson, PhD, climate scientist

Health risks of cooking on a gas stove

If that laundry list of chemicals produced by gas stoves (pre- and post-combustion) hasn’t already raised red flags when it comes to personal health, the research surrounding them might.

1. Carbon monoxide

Carbon monoxide (CO) interferes with oxygen absorption in the blood. “When carbon monoxide levels are too high, the body replaces the oxygen in the red blood cells with carbon monoxide, leading to severe tissue damage or even death,” Hayes says.

Per the U.S. Environmental Protection Agency (EPA), CO levels in homes without gas stoves usually measure between 0.5 and five parts per million (ppm), while homes with properly adjusted and maintained gas stoves are often between five and 15 ppm, and homes with gas stoves not properly adjusted or maintained can be 30 ppm or higher. However, according to the U.S. Consumer Product Safety Commission (CPSC), most people won’t experience adverse symptoms associated with CO—such as headache, nausea, and fatigue—until levels reach between 70 and 150 ppm.

2. Carbon dioxide and methane

While carbon dioxide and methane produced by gas stoves are not so concerning for human health, they are two extremely powerful greenhouse gases that contribute to climate change, indirectly affecting your health. Methane is particularly potent in this regard, with nearly 80 times the warming potential of carbon dioxide.

But particulate matter (up next) is much more alarming when it comes to individual health effects.

3. Particulate matter

“Particulate matter (PM), a mixture of solid particles and liquid droplets, is the most significant form of indoor air pollution in the majority of homes,” says Hayes. He explains that PM exposure is associated with premature death in people with heart or lung disease, cardiac events like heart attack, irregular heartbeat, aggravated asthma, and decreased lung function. These effects are most likely to affect children, older adults, and those with heart or lung disease. While cooking with gas will produce PM regardless of the recipe, the more smoke produced during the cooking process, the higher the PM concentration in your home.

4. Volatile organic compounds

When it comes to health risks associated with VOCs (like benzene) from burning gas stoves, Hayes says this pollutant invisible to the naked eye can result in headaches; loss of coordination; nausea; eye, nose, and throat irritation; damage to the liver, kidneys, and central nervous system; and even cancer³.

The European Union has a set ambient air quality standard for benzene of 5 micrograms per cubic meter (μg/m³), per 2019 data. Physicians, Scientists, and Engineers for Healthy Energy (PSE) measured mean benzene emissions from gas and propane stove burners set on high and ovens set to 350 degrees Fahrenheit, and results ranged anywhere from 2.8 to 6.5 micrograms per minute (μg min–1). The size of the home the stove is in plays a large role in whether or not this rate of benzene emissions would reach the 5 μg/m³ limit.

World Health Organization (WHO) data⁵ also found benzene emissions associated with kerosene-powered stoves to be 44 to 167 μg/m³, and kerosene is a less refined product than natural gas, containing more impurities and contaminants.

5. Nitrous oxides (nitrogen dioxide)

Nitrous oxides may take the cake in terms of negative outcomes. Not only are they nearly 300 times more powerful than carbon dioxide as greenhouse gasses, but they are also associated with some of the most concerning health implications, especially nitrogen dioxide. “Decades of research has shown that nitrogen dioxide causes asthma, so it should not be controversial to acknowledge that nitrogen dioxide coming from our stoves causes asthma, too,” says Jackson.

Research has actually linked gas stove exposure directly to asthma cases. A May 2024 study⁷⁴ in Science Advances found that around 50,000 cases of childhood asthma can be traced to long-term nitrogen dioxide exposure from gas stoves. It also found that the size of the home really matters in this regard, with people living in homes 800 square feet or smaller having four times the amount of nitrogen dioxide exposure than those living in residences greater than 3,000 square feet.

Meanwhile, a 2023 study⁸ in the International Journal of Environmental Research and Public Health estimated that 12.7 percent of all U.S. childhood asthma cases are attributable to gas stove usage. Whereas a 2023 European Public Health Alliance report estimated that over 700,000 children in the European Union experience asthma symptoms because of cooking with gas at home.

While the EPA hasn’t set a standard for indoor nitrous oxide levels, the long-term outdoor exposure limit is 53 parts per billion (ppb). In Canada, the short-term indoor nitrogen dioxide exposure limit is 90 ppb. According to data from the Rocky Mountain Institute, the emissions from gas stoves vary depending on what you’re whipping up:

• Baking a cake in the oven: 230 ppb
• Roasting meat in the oven: 296 ppb
• Frying bacon: 104 ppb
• Boiling water: 184 ppb

But evidence tells us that even lower-level exposures can pose health risks. A 2014 study published in Epidemiology¹³ found that with every 5 ppb of nitrogen dioxide exposure over a 6 ppm threshold, there was a notable increase in asthma severity. Whereas a 2013 meta-analysis¹⁴ discovered that with every 15 ppb increase in nitrogen dioxide exposure, there was a 15 percent increase in wheezing in children.

And while this data is focused primarily on childhood asthma, the concern over these chemicals goes for all living beings in the home—adults and pets included.

The chemicals produced by gas stoves can linger

A Stanford study⁹, led in part by Jackson, found that gas ranges used in poorly ventilated areas can surpass the one-hour national nitrogen dioxide standard within minutes of usage, especially in small kitchens.

The study further discovered that in the 53 homes with gas stoves they studied, all stoves leaked methane—even when they were off. In fact, the evidence showed that over three-quarters of all methane the stoves produced was leaked when the ranges were off, regardless of age and model of the stove.

However, Hayes says, “if properly installed and maintained, very little to no natural gas should leak from a gas cooktop when the burner is off.” Every part of the gas stove should be removed, inspected by a professional, and cleaned at least annually to decrease the likelihood of gas leakage, though recommendations may vary depending on make and model. It’s also a good idea to follow this maintenance protocol if the stove isn’t functioning properly or sounding normal.

“One of our most surprising findings was that pollutant concentrations we measured from gas and propane stoves led to dangerous levels for hours, even after stoves are off—not just in kitchens but in bedrooms down the hall,” Jackson says of the Stanford study. Indeed, according to June 2023 research¹⁰ in Environmental Science and Technology, benzene pollution from gas stove usage stayed at dangerous levels for hours after the stove was turned off, in the kitchen and surrounding rooms in the home as well.

Some of these pollutants can even get stuck on clothes¹¹—especially particulate matter—from which a very small amount can be re-released with fabric motion. However, other gaseous pollutants are not as concerning in this regard. “Gaseous pollutants like nitrogen oxides, methane, and VOCs will dissipate and leave the house. The time it takes for this to occur depends on how well-sealed the house is and the type of ventilation system,” Hayes says.

3 ways to mitigate the health risks of cooking on a gas stove

If you live in a home with a gas stove, these statistics may have you reeling. But there are plenty of actions you can take to mitigate some of the risk associated with this household appliance.

1. Get proper ventilation

When cooking with gas, turn on the hood ventilation above your range—and make sure it’s actually functional. “Research shows that fewer than a third of people use their hoods¹² and that many hoods in people’s homes reduce levels of pollution only modestly,” says Jackson.

To optimize the effectiveness of your ventilation, be sure your range hood is regularly maintained and exhausts outside. “Many homes have range hoods that merely pull air through a coarse filter and recirculate it back into the kitchen. These filters capture larger aerosol particles but do not remove nitrogen oxides or other gasses. To work effectively, these filters need to be cleaned or replaced regularly,” says Hayes.

Ideally, you want to clean the kitchen hood thoroughly every three months and swap out filters every three to six months, again, depending on make and model.

If your kitchen doesn’t have hood ventilation that sends captured particles outdoors (or isn’t regularly maintained), there are other ways to ventilate your kitchen. Hayes suggests opening windows, employing the help of a HEPA filter, or even using a box fan. However, again, these options (really only the HEPA filter) may only remove PM and maybe some VOCs. “They do not remove nitrogen oxides or other gasses,” he says. The real benefit of these options is introducing fresh air into the space, to reduce the concentration of the pollutants.

Given that pollutants can stay at elevated levels for hours, ideally you’d leave an air purifier or box fan running for at least an hour or two after you’ve finished cooking. However, many people keep HEPA filters running in their homes 24/7, which is optimal. While particulates can stick to clothing, it isn’t necessary to change clothes after using your stove (many of us would be changing all day!), but maybe try to not cook a large meal in your PJs that you’ll later wear to bed.

2. Use other cooking appliances

There’s the option of cooking less or preparing dishes that require less stovetop usage. This could include boiling water in an electric kettle to use less gas or opting for a gas-free kitchen cooking tool like a rice cooker, slow cooker, multi-cooker, or air fryer.

“However, the only surefire way to eliminate nitrogen oxide pollution indoors is to trade your gas stove for a cleaner induction or other electric stove,” Jackson says. While this can be a pricey move, the Inflation Reduction Act offers rebates and cost coverage for converting gas-run appliances in your home to electric.

“And you don’t have to switch out cooktops completely. Portable, single-burner induction cooktops are reasonably priced and great for single-pan meals,” says Hayes.

3. Cook with gas wisely

As seen in the above nitrogen dioxide data, certain recipes release more pollutants into the home than others. It can be a great practice to try to limit how often you’re employing higher-emitting cooking techniques. These include recipes requiring long bake times including cakes, roasts, and stews. Frying—deep frying especially—on the stovetop also often utilizes a larger amount of gas and tends to produce higher levels of particulates as a result of the cooking process.

Quick-cooking recipes like pastas, stir fries, egg dishes, oatmeal, and grilled sandwiches are great ways to minimize gas usage—and thus, pollution from gas-fueled stoves.

The bottom line

All the above said, Hayes says he does feel the public concern over gas stoves is disproportionate to the many other sources of indoor air pollutants, like radon and particulates. “My years of work in public health have taught me that when we warn our residents of potential health risks, we need to put those risks in relative context to the myriad hazards we accept daily as part of living in our modern world,” he says.

So while this information on gas stoves is certainly concerning, it’s important to realize that there’s only so much we can do within our circumstances. Taking small actions to mitigate health risks, like employing proper ventilation, is a great place to start.