Air fryers produce fewer toxic particles than traditional frying, study finds

LONDON: A new study from the University of Birmingham suggests that air fryers significantly reduce pollution released during cooking, even when preparing high-fat foods. Compared with conventional frying methods, air frying was found to produce far fewer airborne pollutants.

The research, published in the American Chemical Society journal ES&T Air, is among the first to comprehensively examine the range of pollutants emitted during air frying.

Across multiple food types, researchers recorded lower emissions of volatile organic compounds (VOCs) and ultrafine particles than those typically produced by shallow frying or deep-fat frying.

In the latest study, the team investigated whether the fat content of foods influences airborne emissions. While VOCs and ultrafine particles have been linked to various health risks, indoor pollution sources such as cooking have received far less attention than outdoor air pollution.

Measuring Emissions From Different Foods

To closely monitor cooking emissions, researchers conducted experiments in custom-built air quality chambers capable of detecting small changes in VOCs and ultrafine particles. A commercially available 4.7-litre air fryer was used to cook frozen fried foods, fresh low-fat foods, and fresh high-fat foods under controlled conditions.

Among air-fried foods, frozen onion rings—possibly due to their pre-fried oil coating—as well as smoked and unsmoked bacon, produced the highest emission levels. Researchers attributed this to the cured fat content and thin shape of bacon, which allows fats to fry almost instantly.

However, the most striking differences were observed when high-fat foods were cooked using other methods. Deep-fat frying produced VOC levels 10 to 100 times higher than air frying. The results mirror earlier experiments conducted in a research kitchen, where cooking lean chicken breast in oil led to similarly elevated pollutant levels compared with air frying.

Health Implications and Expert Insights

Ruijie Tang, the study’s first author and a final-year PhD student at the University of Birmingham, said the findings highlight the benefits of air frying.

“The results confirm that while high-fat foods do produce more emissions when air-fried, these emissions are only a fraction of those generated by shallow or deep-fat frying,” Tang said. “Using a bespoke air quality chamber allowed us to isolate cooking-related pollutants and gain a much clearer picture of emissions from air frying.”

The researchers suggest that choosing air frying over traditional frying methods could help reduce indoor air pollution and associated health risks.