Travel & Lifestyle: Is It Safe To Use A Gas Stove?

Almost a century ago, the natural gas industry came up with a marketing slogan so successful, it became synonymous with being better: “Now you’re cooking with gas.” And many chefs, both at home and professionally, would agree that gas cooking’s more responsive heat control and lower cost give it an edge over electric ranges. That may be why more than three-quarters of restaurants cook with natural gas, according to a survey conducted by the National Restaurant Association.

But cooking with gas does have a downside. Natural gas contains hazardous air pollutants, and burning it gives off even more, which is one of the reasons there was talk of banning gas stoves several years ago.

Experts say that while some jurisdictions, including those in New York City and California, have started to impose certain limits on new gas connections, this is motivated more by climate concerns than anything else (and is already being challenged in court). “Natural gas combustion is a significant contributor to greenhouse gas emissions,” said Darby Jack, professor of Environmental Health Sciences at Columbia University Irving Medical Center in New York City.

When it comes to the impact of natural gas on human health, Jack said, “This is an active area of research.” While the short- and long-term effects are still being studied, he said, “It is abundantly clear that when you burn gas inside, it’s a significant source of unhealthy chemicals.” But the concentrations of those chemicals and their impact on humans in the vicinity depend on many factors.

We asked Jack and Eric Lebel, a senior scientist at PSE Healthy Energy in Oakland, who has studied indoor gas emissions for more than seven years, what the 38% of American households that cook with natural gas should know.

Natural gas is 92% methane, which is not a concern at low levels in terms of human toxicity. However, PSE tested nearly 600 unburned samples of natural gas from nearly 500 residences in 17 North American cities, and practically all of them (97%) contained benzene, a known carcinogen, in varying amounts, along with other hazardous air pollutants. The World Health Organization (WHO) says there is no safe exposure level to benzine, says Lebel, and the effects are cumulative over time. Los Angeles and Denver had concentrations twice as high as those of other cities sampled.

Igniting the gas, as you do when cooking, causes other toxic chemicals to be released, the most notable of which is nitrous dioxide, or nox. Some studies have linked NO2 to asthma in children. “It’s not quite cumulative in the same way benzene is, but it is a respiratory irritant,” Lebel said. “Typically, we see concentrations hang around for a few hours and even migrate from the kitchen to bedrooms.”

Natural gas leaks have been known to cause deaths from explosions or carbon monoxide (CO) poisoning, according to the Environmental Protection Agency. Natural gas itself doesn’t contain carbon monoxide, but the incomplete combustion of natural gas can produce it.

Usually, natural gas has a chemical added to odorize it, making a leak noticeable. But sometimes the leaks aren’t noticed until it’s too late. The Centers for Disease Control and Prevention estimates that CO poisoning is responsible for nearly 400 deaths and more than 100,000 emergency room visits each year in the United States.

While there are monitors for all these chemicals that you can buy, they are typically not affordable or useful for consumers (the exception being carbon monoxide detectors). When it comes to methane, benzene and nox, “Home monitoring is not a cornerstone of prevention,” Jack said. Your best approach is to minimize the production of these toxins whenever possible.

There are plenty of solutions that don’t involve completely remodeling your kitchen, Lebel said. The best is to have an appropriate exhaust hood — meaning one that vents to the outdoors rather than just recirculating and is powerful enough for your cooking appliances — and use it.

Research shows that only one in three people commonly turn on their range hood when cooking, according to Lebel. His advice? “Use it, even if you’re only boiling water or preheating the oven.” And keep it on for at least 10-20 minutes after you turn the oven off to make sure you’ve exhausted any unwanted chemicals. If your exhaust isn’t adequate, Jack says opening a window while you cook is the second-best option.

The power of an exhaust hood is measured in cubic feet per minute or CFM. A general industry rule of thumb is that you need 1 CFM for every 100 BTUs (British thermal unit, a measure of heat) your range produces. So, if your gas range produces 45,000 BTUs, look for a hood that can move 450 CFM.

Another way to calculate this is to add up the total BTUs of all your burners and divide by 100. So if your stove produces a total of 60,000 BTUs, your exhaust hood must be at least 600 CFM. Other factors, including the length and number of bends in the ductwork and the size of your kitchen, can also come into play.

Both natural gas and propane stoves have similar issues with nox and benzene emissions, and in fact, Level said, some of the improvements in home appliances like power boil burners actually create more nox. The more you use your gas stove, and the higher the temperature, the more nox you’re making, he said.

Companies haven’t shown interest in developing low-nox burners, but many homeowners are reluctant to make the switch to electric, which is traditionally pricier and less efficient, and may impact their home’s resale value. Induction cooking, which uses an electric outlet, is an alternative, but tends to be more expensive and less familiar to home cooks.

As for whether the switch is necessary from a health perspective, Jack said, “We don’t have good evidence showing there is a direct health benefit to switching from gas to electric.” Although there is evidence that doing so reduces nox, he said, “It’s still questionable whether that impacts health and how much.”

Risk depends on a number of factors, including age, exposure level, and any pre-existing health conditions. If you work in a restaurant cooking on gas all day and also have a gas stove at home, your exposure level will naturally be higher, and the impact on your health will be greater.

“My take,” Jack said, “is that a healthy adult does not need to worry. A household with young children or anyone with respiratory conditions may be at more risk.” He does admit that there is disagreement on this in the scientific community, however.