Ventilation While Cooking

Contaminants Released During Cooking

Cooking is an important part of our everyday lives. However, some emissions from cooking contribute to indoor air pollution. It's important to use proper exhaust ventilation to help remove pollutants. Cooking on all stove types produces fine particulate matter (PM2.5), which is a mixture of small particles that can be inhaled deep into the lungs.

Decades of research show long-term exposure to PM2.5 increases the risk of premature death in people with existing heart or lung disease. Long-term exposure is also linked with an increased risk of developing chronic heart and lung conditions, impacts on brain health, and adverse birth outcomes. Short-term exposure to PM2.5 can worsen existing heart or lung conditions and can increase hospitalization among these populations. PM2.5 released during cooking can also contain polycyclic aromatic hydrocarbons, some of which are known to cause cancer.

Contaminants From Gas Stoves

Gas stoves produce a harmful contaminant called nitrogen dioxide (NO2). Some NO2 may be all around us from sources like traffic pollution, but using a gas stove increases NO2 levels indoors. A 2006 study1 in Massachusetts and Connecticut found that homes with gas stoves had, on average, nearly 3 times more NO2 than homes with electric stoves over a 1- to 2-week period. According to EPA2, NO2 levels in homes with gas stoves are 1.5 to 4 times higher than in homes with electric stoves.

Indoor NO2 can make asthma and other breathing problems worse for children. The same 2006 study found that pollution from gas stoves more than doubles the odds of wheezing and shortness of breath for kids with asthma living in multifamily housing. Further, a 2011 study3 from New Zealand found kids with asthma who live with higher NO2 levels use their rescue inhalers 14% more often.

In addition to NO2, gas stoves release other pollutants, including the known cancer-causing agent benzene, and the toxic gas carbon monoxide. When gas stoves are on for long periods of time, carbon monoxide concentrations can build to unsafe levels. Install carbon monoxide alarms and check them regularly. Never use a gas stove or oven for heating your home. Have your gas appliances serviced every year.

Improving Health with Proper Ventilation

Vented hood over a kitchen stove.
A ducted range hood that sends air outside can remove cooking emissions.

Ventilating a space with sufficient air flow dilutes or removes indoor contaminants from any kind of stove. A fan that exhausts to the outside is critically important to remove harmful gases and particles cooking produces, including those from lighting burners, heating oil, and cooking food. Replacing gas stoves with electric stoves also removes gas-stove-specific pollutants like NO2.

Many homes do not have any form of kitchen ventilation. If you do not have an exhaust fan, open nearby windows or doors to create a breeze that moves air across the room.

Range hoods are one type of kitchen exhaust that consists of a fan, usually with a screen, placed above a stovetop. Range hoods either draw air up through ducting and exhaust it elsewhere, or they recirculate air back into the kitchen (also known as a ductless or recirculating hood). Recirculating hoods are generally much less effective than ducted hoods in removing pollution from cooking.

It is important to duct kitchen exhaust to the outside and not into the attic or crawlspace. A professional can figure out where ducts release exhaust. Gas stoves need higher airflow to remove pollutants from gas and cooking than electric stoves.

Tips to reduce indoor air pollution from cooking:

  • Use a range hood (kitchen exhaust) every time you cook.
  • If you do not have an exhaust fan, open nearby windows or doors to create a breeze that moves air across the room. Consider using a properly selected HEPA portable air cleaner (PDF).
  • Cook on the back burners when possible.
  • Use the maximum airflow setting of the hood.
  • Lower the cooking heat when possible. Fry and broil less often.
  • Follow the manufacturer instructions to maintain your hood, including regularly washing the metal screens.
  • If you have a recirculating hood, replace the filters, per manufacturer instructions.

Climate Effects of Gas Stoves

Natural gas is mainly methane. At the levels emitted from gas stoves, methane isn't generally a direct health threat, but it is a potent greenhouse gas, 84 times more effective at trapping heat than carbon dioxide over 20 years. Gas stoves typically use far less natural gas than water heaters and furnaces. Since methane contributes 20% of Washington state's greenhouse gas emissions, reducing reliance on all natural gas appliances is environmentally beneficial, in addition to improving public health.

Disparities in the Effects of Gas Stoves and Cooking Pollution

The risks of pollution from cooking and gas stoves are exacerbated by existing inequities. These include disparities in air pollution exposure, rates of chronic conditions, and housing that in part result from structural racism.

On average in Washington, Black and Asian people are exposed to higher levels of PM2.5 compared to other groups. This increases their risk of cooking-related and gas stove-related health impacts, due to their higher overall pollution burden. Based on 2014 data, Black people were exposed to levels of PM2.5 over 1.3 times higher than white people, and Asian people were exposed to levels 1.5 times higher.

People with asthma are at higher risk of health impacts from gas stoves. American Indian/Alaska Native adults have the highest asthma rates (18%), while Black and Pacific Islander adults also face elevated rates (11%) compared to other groups.

Indoor cooking pollution is often more concentrated in smaller homes, with Black and American Indian/Alaska Native households occupying a larger share of units under 1,000 square feet, leading to higher pollution burden for these households. Homeownership enables easier modifications like switching the type of stove and installing or improving kitchen exhaust systems. As a consequence, it is generally easier for white households in Washington to make these changes, with a homeownership rate over 2 times that of Black households, 1.5 times the rate of Hispanic households, and 1.3 times the rate of American Indian and Alaska Native households.

More Resources

Cooking Impacts on Indoor Air Quality, Health, and Climate (PDF)

Indoor Air Quality, Washington State Department of Health

Combustion Pollutants in Your Home Guidelines, California Air Resources Board

Indoor Air Pollution from Cooking, California Air Resources Board

References

1. Belanger, K., et al. (2006). Association of indoor nitrogen dioxide exposure with respiratory symptoms in children with asthma. American Journal of Respiratory and Critical Care Medicine, 173(3), 297-303

2. U.S. EPA (2008). Integrated Science Assessment for Oxides of Nitrogen – Health Criteria (Report No. EPA/600/R-08/071). EPA.

3. Gillespie-Bennett, J., et al. (2010). The respiratory health effects of nitrogen dioxide in children with asthma. European Respiratory Journal, 38(2), 303-309