Is Your Gas Range a Health Risk?

Consumer Reports' tests underscore the importance of using ventilation like range hoods and fans

Gas ranges have been the gold standard in cooking for decades. People love how responsive they are, that you can use them with different kinds of cookware, and, of course, the look of the real flame. But that beloved flame has also raised concerns.

One particular issue: nitrogen oxides, or NOx. These are gases that, outdoors, come primarily from vehicles and power plants and that can cause some of the haze associated with smog. But growing evidence suggests that gas ranges can also emit NOx. That's worrisome, because research has tied prolonged exposure to these compounds to the development or worsening of asthma, lung infections, and other respiratory issues, especially in children, the elderly, and those with underlying breathing problems.

Dave Schryver, the CEO and president of the American Public Gas Association, a trade organization, says the Environmental Protection Agency does not list natural gas as a major contributor to negative indoor air quality or a health hazard for consumers.

But Ashita Kapoor, CR's associate director of product safety, points out that the EPA currently does not have indoor air quality standards. And, she notes, the Consumer Product Safety Commission, the federal agency tasked with ensuring the safety of household products, has warned about the health effects of nitrogen oxides and indoor air pollution for years. Most recently the agency announced it was seeking public comment on gas stove emissions and potential solutions, but CPSC chairman Alex Hoehn-Saric has been very clear he is "not looking to ban gas stoves."

Consumer Reports has tested gas stoves for decades and continues to rate and recommend dozens of models based on their performance and reliability. As with many of the home products we evaluate, we look at potential risks and ways to mitigate them. To investigate the concerns raised by gas emissions and see if ventilation reduces those levels, CR recently completed two rounds of testing to measure emissions of NOx and other gases from five typical gas ranges and a single gas cooktop, in a controlled setting designed to mimic people cooking at home in a typical kitchen.

"Our tests found NO₂ at levels above those recommended by some public health organizations for indoors, particularly when the ranges were used without ventilation and when a burner was set on high," Kapoor says. "That's alarming."

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To test the ranges, CR built an insulated chamber with a range hood and ventilation fan, as your home kitchen might have. We then performed more than 50 tests across the five ranges and lone cooktop, to measure levels of not only NOx but also carbon monoxide, carbon dioxide, and particulate matter. We also measured oxygen levels to see whether they dropped dangerously low. And while we performed our testing using ranges and a cooktop that run on natural gas, our experts expect the results would be similar when using propane, given the similar combustion of the two gases.

We put some monitors close to the ranges and some further away, to capture approximate gas levels for people cooking at the range as well as those standing nearby.

The ranges and cooktop were tested separately, first with a single burner on low and then with the same burner on high. We tested with and without ventilation, and with multiple range hoods, recording data for 90 minutes.

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None of our testing revealed dangerous levels of carbon monoxide or particulate matter, nor did oxygen drop to unsafe levels.

But in many tests we recorded elevated levels of carbon dioxide and, even more concerning to Kapoor, nitrogen dioxide, one of the NOx gases CR measured. Those gases are "more potent with respect to acute toxicity," she says, making them more likely to cause problems even in the short time frame that people typically take while preparing a meal.

In multiple instances, we recorded elevated levels of nitrogen dioxide with a single burner set to low. And while using a range hood or downdraft hood helped lower levels, in a number of tests we still recorded levels that exceeded 1-hour guidelines set by the World Health Organization.

The results were worse when our burners were set to high. "All five ranges, as well as the cooktop, produced potentially worrisome levels of nitrogen oxides," Kapoor says.

Still, CR's evaluation did show that range hoods can help, and that a number of other steps can help, too.

Here are the main takeaways from our tests.

We tested five gas ranges and a single gas cooktop, with prices ranging from $600 to $3,500. Our testing found that there wasn't any correlation between cost and total pollutants produced.

Most 30-inch gas ranges and cooktops have four or five burners, with maximum BTU (British thermal unit) ratings between 5,000 and 20,000 BTUs, per burner.

When we tested a single burner, set to low, on each of our stoves and the single cooktop, we found that levels of harmful emissions stayed below the thresholds deemed safe by our experts, provided that one of the range hoods was used at the same time. When a hood wasn't used, most of our readings exceeded safe levels.

But when we repeated the test with the same burners set to high, all five stoves, along with the cooktop, produced levels of nitrogen oxides that were potentially harmful according to our experts, even when we used them with the range hood and the ceiling-mounted ventilation fan—meant to mimic typical HVAC in a home—turned on.

Moreover, we did find a correlation between larger, higher-BTU burners, and increased levels of pollutants. It stands to reason therefore that a range with multiple high-BTU burners, such as a pro-style range, could produce greater levels of emissions. We did not specifically test pro-style ranges since they only represent a small percentage of the marketplace.

When used on their own, none of the ventilation systems we tested adequately prevented a buildup of nitrogen oxides when a burner was set at high. This was true on all gas ranges as well as on the one cooktop.

But both ventilation methods did help to varying degrees, and are still much better than no ventilation at all. The top-mounted hood was more effective than the downdraft hood.

While there's no perfect fix for an existing gas stove, there are steps you can take right now to minimize your risk.

Ventilate. If you don't already have a ventilation system in your kitchen, get one if you can. Ideally, opt for the highest-powered hood or backdraft fan that's practical and that you can afford. "Despite 85 percent of gas stove users having a vent, hood, or fan above their stovetop, fewer than 20 percent use it every time," Kapoor says. "Range hoods, which primarily draw air around the surface of a stovetop upward, seem to capture lighter gases, but seem to struggle with heavier gases like nitrogen oxides and carbon dioxide. This led CR to explore different mitigation strategies that could potentially capture a higher level of byproducts from natural gas combustion."

In addition to using a range hood every time you cook, open windows and doors and run a fan. Moving the air can help prevent nitrogen oxides from concentrating at dangerous levels in a single location. Consider a smart range hood, which connects to a smart range or cooktop and turns on automatically every time a burner is activated.

Cook carefully. Cooking with fewer burners and over lower heat could potentially offset some degree of risk. One-pot meals and dishes cooked for shorter stretches over a smaller flame may result in less gas burned and in turn, reduced risk.

Look to supplemental appliances like portable induction cooktops, electric toaster ovens, microwaves, and multicookers when practical. If you live with anyone considered to be of elevated risk, encourage them to stay out of the kitchen during meal prep.

If you’re getting a new range, consider electric or induction cooking. Many electric and induction ranges in our tests outperform their gas counterparts, and without the risks. While this can be an expensive shift, the Inflation Reduction Act provides credits of up to $840 for the purchase of a new electric or induction range or cooktop, or electric wall oven, as well as up to $500 to offset the costs of running new wiring. A number of electric ranges in our ratings cost less than that, and would be effectively free to those who qualify. We expect to see these incentives rolled out more broadly in the second half of 2023.

CR recently assessed seven portable induction burners, which resemble one- or two-burner hotplates but run on induction technology. These tools are far faster to cook, and more efficient, than traditional hotplates, which relied on resistance heating. In fact, when we tested the burners in our labs, we found that the best could heat water nearly as fast as many gas ranges. Best of all, some can be had for under $100, and they can be plugged into a typical 110-volt electric outlet, meaning you won't need new wiring or a pricey retrofit to use them.

Editor's Note: This project was funded in part with a grant from Climate Imperative Foundation, an organization committed to supporting data-driven climate policy decisions. This article, originally published Oct. 4, 2022, has been updated to include the results of additional testing.

Paul Hope

Paul Hope is a senior multimedia content creator at Consumer Reports and a trained chef. He covers ranges, cooktops, and wall ovens, as well as grills, drills, outdoor power tools, decking, and wood stains. Before joining CR in 2016, he tested kitchen products at Good Housekeeping and covered tools and remodeling for This Old House magazine. You’ll typically find him in his old fixer-upper, engrossed in a DIY project or trying out a new recipe.