Air fryers, the countertop appliances that have surged in popularity for their promise of healthier meals, may also offer a hidden benefit: cleaner indoor air. A new study from the University of Birmingham suggests that cooking even fatty foods in an air fryer produces far fewer airborne pollutants than conventional frying methods.
The research, published in the American Chemical Society’s journal ES&T Air, measured emissions of volatile organic compounds (VOCs), nitrogen oxides (NOx), and ultrafine particles (UFPs) during the air frying of 12 different dishes. Using a custom-built air quality chamber and a standard 4.7-litre air fryer, researchers compared results against shallow and deep-fat frying.
“This study is the latest that shows the potential benefits for indoor air quality of using air fryers for cooking,” said Professor Christian Pfrang, lead author.
“While our previous study only looked at one type of food, lean chicken, we wanted to look at a greater range of foodstuffs, including ones with higher fat content, to see how they compare specifically when cooked in an air fryer.”
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Researchers found that foods cooked in an air fryer released fewer VOCs and UFPs than those cooked by shallow or deep-fat frying. Frozen onion rings and bacon produced the highest levels of pollutants in the air fryer, but still at a fraction of the levels seen in deep-fat frying, sometimes 10 to 100 times lower.
Tests showed that older air fryers, used more than 70 times, emitted more pollutants due to residue buildup in hard-to-clean areas.
Ketones, aldehydes, and alkenes, compounds linked to health concerns, were detected, but concentrations remained well below UK government indoor air quality limits.
Ruijie Tang, the study’s first author and a PhD student at Birmingham, noted:
“The results confirmed that while foods with high fat content do produce more emissions in the air fryer, they produce only a fraction of what we see in cooking methods such as shallow or deep-fat frying.”
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Cooking is a major source of indoor air pollution, with frying known to release ultrafine particles that penetrate deep into the lungs. The findings suggest that air fryers could help reduce exposure, especially in small kitchens with limited ventilation.
Still, researchers caution that design improvements are needed.
“Repeated use of air fryers without being able to clean the more inaccessible cooking surfaces can negate some of the benefits for indoor air quality,” Pfrang said.
He added that manufacturers should consider designs that allow for deeper cleaning to keep emissions low over time.
Indoor air quality is increasingly recognized as a public health issue. While air fryers are not emission-free, the Birmingham study provides some of the first detailed evidence that they are cleaner than traditional frying methods.
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As households continue to embrace low-oil cooking, the findings could influence both consumer choices and appliance design.
“Our body of work will provide households with a better understanding of how kitchen activities affect the air we breathe in our homes,” Pfrang said.
Journal Reference:
- Ruijie Tang, Yizhou Su, William Joe F. Acton, Lara K. Dunn, and Christian Pfrang. Quantification of Volatile Organic Compounds (VOCs), Nitrogen Oxides (NOx), and Ultrafine Particles (UFPs) Emitted by Domestic Air Fryers: A Chamber Study of Indoor Air Quality Impacts. ACS ES&T Air. DOI: 10.1021/acsestair.5c00363
