Natural Gas for Heating and Cooking Contains Elevated Levels of Carcinogens and Hazardous Air Pollutants

Kitchen Stove

Even low-level gas leaks from kitchen stoves when they are off can generate benzene concentrations in homes up to seven times California’s recommended exposure limit.

Leaks from gas stoves can create potentially hazardous indoor benzene concentrations.

Scientists find natural gas throughout California contains numerous hazardous air pollutants that can impact air quality and public health.

According to new research from the nonprofit energy science and policy research institute PSE Healthy Energy, the natural gas piped into millions of California homes for heating and cooking contains elevated levels of carcinogens and hazardous air pollutants. Published in Environmental Science & Technology on October 20, the study found that even low-level gas leaks from kitchen stoves when they are off can generate benzene concentrations in homes up to seven times California’s recommended exposure limit. These concentrations are in addition to benzene leaks that may occur when the stove is in use.

“Natural gas leaks are a source of hazardous air pollutants that have largely been overlooked.” — Drew Michanowicz

“Stoves leak small amounts of gas all the time, even when they are off. While these leaks are often too small to smell, they can still impact air quality and increase human health risks in our homes,” said lead author Dr. Eric Lebel, senior scientist at PSE Healthy Energy. “We found that just having a gas stove can create benzene concentrations in the kitchen comparable to secondhand smoke.”

According to the authors, the study provides the most comprehensive data to date on the concentration of hazardous air pollutants in California’s distribution-level natural gas.

Researchers collected 185 individual samples of unburned gas from kitchen stoves across the state. In nearly every sample, they detected benzene and other hazardous air pollutants. This included samples across all three  of the state’s major gas utilities: Pacific Gas and Electric (PG&E), Southern California Gas Company (SoCalGas), and San Diego Gas and Electric (SDG&E). Of the 10 most commonly detected pollutants, six are federally-designated hazardous air pollutants under the Clean Air Act.

Concentrations of pollutants varied throughout the state, with the highest levels found in Los Angeles County. Exceptionally high benzene concentrations were observed in the North San Fernando and Santa Clarita Valleys, where the study’s maximum benzene concentration of 66 ppmv was observed. This is a level approximately 30 times greater than the statewide average.

“We found that just having a gas stove can create benzene concentrations in the kitchen comparable to secondhand smoke.” — Dr. Eric Lebel

Scientists also calculated the potential for gas leaks to impact outdoor air quality. Using existing emissions data, the researchers found that California’s gas appliances and distribution-level infrastructure leak the same amount of benzene as the emissions from nearly 60,000 cars each year.

“Natural gas leaks are a source of hazardous air pollutants that have largely been overlooked,” said PSE Healthy Energy Senior Scientist Drew Michanowicz. “Policies that phase out gas appliances are not only good for our climate, our study shows that these policies also provide important public health benefits by improving indoor and outdoor air quality.”

The study comes as the state of California charts a transition from gas appliances in homes to electric alternatives over climate and health concerns. Last month, California air regulators approved a first-in-the nation commitment to phase out the sale of gas furnaces and water heaters by 2030—a move that will transition millions of homes to electric alternatives, such as heat pumps. The state has also moved to phase out subsidies for connecting new homes to the gas system, and is considering ending rebates for gas appliances to incentivize the transition to electric alternatives.

Reference: “Composition, Emissions, and Air Quality Impacts of Hazardous Air Pollutants in Unburned Natural Gas from Residential Stoves in California” by Eric D. Lebel, Drew R. Michanowicz, Kelsey R. Bilsback, Lee Ann L. Hill, Jackson S. W. Goldman, Jeremy K. Domen, Jessie M. Jaeger, Angélica Ruiz and Seth B. C. Shonkoff, 20 October 2022, Environmental Science & Technology.
DOI: 10.1021/acs.est.2c02581

PSE Healthy Energy is a nonprofit research institute dedicated to supplying evidence-based scientific and technical information on the public health, environmental, and climate dimensions of energy production and use. We are the only interdisciplinary collaboration focused specifically on health and sustainability at the intersection of energy science and policy.

13 Comments on "Natural Gas for Heating and Cooking Contains Elevated Levels of Carcinogens and Hazardous Air Pollutants"

  1. Użytkownicy pieców węglowych musieli je wymienić na gazowe, aby nie chorować na raka.
    Teraz użytkownicy tychże muszą sobie kupić elektryczne auta , żeby nie chorować na RAKA.
    Posiadaczom tych aut zalecacir wymienić instalacje gazowe na elektryczne, żeby NIE CHOROWAĆ NA RAKA…
    Ależ propaganda!

  2. What kind of cancers result from exposure to natural gas? What is the rate above the background rate for those cancers?

    What are people supposed to do if their location isn’t amenable to heat pumps, such as thin soils, or no yards?

    These politicians dictating our life styles obviously aren’t chess players.

  3. Only a Troll would say nat gas is not toxic. Maybe they don’t need red blood cells.
    Benzene is the concern with nat gas. 5 ppm fir 25 minutes is allowable workday standard. 24 hrs a day in homes with gas stoves are not healthy. Cancer of the blood Benzene affects bone marrow. Terrible way to die.

    This info was bound to come out eventually – we were talking about gas stoves’ benzene in the 1970s. Since, yea, thx, good job.

    This might be the first news story since then .

    • “5 ppm fir 25 minutes is allowable workday standard.”

      The study says the 66ppm was measured in the outdoor air in the San Fernando Valley! Perhaps the benzene should be removed before distribution.

      I don’t believe anyone here, troll or not, has expressed the opinion that natural gas is not toxic.

      • “About half of the exposure to benzene in the United States results from smoking tobacco or from exposure to tobacco smoke.”

        • As the article acknowledges, second-hand tobacco smoke is a major source of benzene. Forest fires are known to produce benzene. I think that one can safely assume that any burning vegetable matter will produce benzene. There has been an ongoing push to legalize the medical and recreational use of marijuana. I wonder if anyone has analyzed the benzene inhaled from smoking marijuana.

          It is interesting that many substances are labeled as toxic or carcinogenic, often at the threshold of detection, and are banned. Yet, some things get a pass. Is that rational?

  4. So if I’m reading the study correctly, they measured benzene in natural gas samples, then used estimated stove leak rates and predicted benzene concentrations in a kitchen using a model. And that model estimated levels below California EPA maximum safety levels most of the time, but under certain conditions it could be higher (those conditions were not disclosed). So no actual benzene emissions in any buildings were measured, and if we estimate them, they’re within safe levels most of the time.

    Why are we talking about this?

  5. Jeannette Heaton | October 29, 2022 at 1:54 pm | Reply

    and Would benzene cause a rare brain disease? My boyfriend worked with a natural gas company and died of a rare brain disease and had to be on oxygen 24/7 for 11 years. He had trouble breathing.He died In June of this year. He was an inspector with his company.

  6. This article is rather meant for EU people as they are going to freeze to death. But at least they will know they will freeze in safe environment.

  7. I am not surprised that this comes from California, what with modeled everything and all. Estimated leaks? Based on whose stove? How old was it? It is unbelievable that leaking gas could raise any kitchen with a legally installed stove to 66 ppm of benzene or CO for that matter. There is too much ventilation and gas has so little benzene and leaks, if any, are so small, and exposure is so limited, and the health impact so insignificant. This is the second paper this year claiming that natural gas stoves are a source of in-home toxic air. The other one claimed that NOx (which is created in high temperature flames) was too high. Now that can be real, in certain cases and there are statutory limits imposed on the mass production rate, and the cure is easy – turn down the flame temperature by having a multitude of little flamelets. Oh wait, they universally do that already. Never mind.

  8. More anti nat gas propaganda from the uninformed electrify everything.

  9. Be careful going electric least Thor emf’s will kill you dead as a doorknob

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