Cooking with Gas

The Republican-controlled House approved bills that protect gas stoves from overzealous government regulators. One bill would prohibit use of federal money to regulate gas stoves as a hazardous product; a separate measure would block an Energy Department rule setting stricter energy efficiency standards for stovetops and ovens.

Neither bill is expected to advance in the Senate, and the Biden administration does not support any attempt to ban the use of gas stoves.

Cooking with gas (from flamingoappliance.com/oven-repair/gas-stove-maintenance-tips/).

Welcome back. What is going on with gas stoves? Permit me to skip the politics and jump to the science. To help explain the issue I’ll review a recent study of the carcinogen benzene by researchers affiliated with Stanford University, PSE Healthy Energy, University of California, Berkeley and Lawrence Berkely National Lab.

Natural Gas Emissions
Natural gas appliances emit carbon dioxide through combustion and methane through leaks and incomplete combustion. Methane, the principal component of natural gas, is second only to carbon dioxide as a greenhouse gas contributor to global climate change. Home gas appliances also release health-damaging air pollutants, though only stoves typically release these pollutants into home air rather than through outdoor vents.

Some 47 million U.S. households cook with gas. A recent population-level analysis concluded that approximately 12% of childhood asthma in the U.S. is attributable to gas stoves.

Benzene
Benzene, a chemical linked to a higher risk of leukemia and other blood cell cancers, forms in flames and other high-temperature environments, such as oil field and refinery gas flares. Unfortunately, benzene also forms in gas stove flames.

The researchers sampled 87 stoves in 14 California and Colorado counties between January and December 2022. Sampled residences included kitchens in homes, apartments and Airbnb rentals. They calculated benzene emission rates attributable to gas combustion by measuring the increase in benzene concentration over time in sealed and unsealed kitchens, sometimes testing more than one burner or oven separately.

They also measured benzene concentrations in kitchens and bedrooms for various stove-use scenarios, such as cooking a meal on a gas range. In six houses, they measured 8-hour time course concentrations in open kitchens, without using fans or other active air circulation means. Ovens were set to 475 °F for 1.5 hours, and after turning off the oven, benzene concentrations were monitored for 6.5 more hours in the bedroom farthest from the kitchen.

Benzene Sampling Results
Benzene emissions from gas and propane burners and ovens were substantial, much higher than electric modes, and repeatable for replicates of gas ovens at 350 °F and gas burners set on high up to three months apart. In a subset of the sample, a single gas burner or oven raised kitchen benzene concentrations above the upper range of indoor benzene concentrations attributable to secondhand tobacco smoke.

Benzene emission rates (micrograms/minute) per stove type and setting (Table 2, from pubs.acs.org/doi/10.1021/acs.est.2c09289).

In all six cases of ambient benzene in bedrooms farthest from open kitchens’ burner or oven use, the elevated peak bedroom benzene concentrations were 5 to 70 times above baseline levels. In some cases, they exceeded the California Office of Environmental Health Hazard Assessment acute and chronic Reference Exposure Levels.

Wrap Up
The study findings suggest that concentrations of benzene produced by gas and propane combustion in stoves and ovens may increase health risks, especially if the hood is not used regularly and vented to the outside.

The results also suggest that the EPA significantly underestimates benzene emissions from residential gas combustion. Though the quantity of benzene attributable to stoves and ovens is small, it could have a disproportionate effect on health because the benzene is emitted directly indoors.

The researchers emphasize that further research is needed to assess actual exposures and the full health impacts. In the meantime, it’s your call regarding overzealous government regulators and stricter energy efficiency standards for stovetops and ovens. Thanks for stopping by.

P.S.
House bills to protect gas stoves: apnews.com/article/gas-stoves-ban-biden-energy-climate-regulation-d70577c96570cffd8bec84129b2c1a29
Benzene public health statement: www.atsdr.cdc.gov/ToxProfiles/tp3-c1-b.pdf
Study of U.S. gas stoves and childhood asthma in Inter. Jour. of Environmental Research and Public Health: www.mdpi.com/1660-4601/20/1/75
Study of benzene from stove gas and propane combustion in Environmental Science & Technology journal: pubs.acs.org/doi/10.1021/acs.est.2c09289
Article on study on EurekAlert! website: www.eurekalert.org/news-releases/992631