Great news for adults who rely on the ease of air-frying their favorite frozen appetizer after a long day at work: Researchers at the University of Birmingham have confirmed that air fryers are the “least polluting” cooking method in your kitchen.

As indoor air quality becomes a hot topic amid airborne viruses and ongoing concerns about health and climate safety, scientists agree: Cooking is a key source of indoor air pollution.

Considering most people spend more than 80% of their time indoors, indoor pollutants can have major impacts on health, including chronic conditions like cardiovascular, neurodegenerative, and respiratory diseases.

The researchers, based in the University of Birmingham’s School of Geography, Earth, and Environmental Sciences, noted that air fryers have been studied for their energy efficiency but have not been widely considered for their potential environmental benefits.

Their study, which was recently published in Indoor Air, involved using a campus research kitchen, as opposed to a laboratory chamber, to most accurately measure pollution from different cooking methods where they are most likely to be used. 

In the introduction of the study, the authors wrote: “Although previous studies were conducted in a variety of venues, including domestic and commercial kitchens, canteens, and laboratory chambers, there are fewer cooking emission assessments carried out in a well-controlled, but fully equipped research kitchen that can simulate a real-life domestic kitchen with controlled conditions, specifically fixing the ventilation to a relatively low level.”

Once they were set up at their cooking stations, they ran a number of experiments, cooking a chicken breast using five different methods: Pan-frying, stir-frying, deep-fat frying, boiling, and air-frying. They measured the levels of particulate matter and volatile organic compounds (VOCs) emitted by each.

“There are a number of factors that will affect the levels of pollution from cooking alongside the method used, including the amount of oil used, and the temperature of the stove,” lead author Professor Christian Pfrang said in a statement.

“What we can say with certainty, however, is that improving the ventilation in kitchens by opening windows or using extractor fans, will help to disperse polluting particles and reduce personal exposure.”

What they can also say is that the air fryer method measured in at a fraction of the air pollution of pan-frying and stir-frying. 

The team measured particulate matter in peak concentrations in micrograms per cubic meter of air. Pan-frying saw a peak concentration of 92.9, and stir-frying at 26.7.

But boiling saw 0.7 and air-frying weighed in at 0.6.

In measuring VOCs, the results were measured in ‘parts per billion.’ Pan-frying recorded 260 ppb of VOCs, deep frying 230 ppb, and stir-frying ppb. But boiling once again came out just above air-frying, with 30 ppb and 20 ppb, respectively.

While air-frying was confirmed as the “least polluting” cooking method when it comes to indoor air quality, it, of course, doesn’t entirely remove air pollution from the act of cooking indoors. 

“It’s also really important to understand that particles will remain in the air for quite some time after you have finished cooking,” Professor Pfrang added.

He provides some simple tips to keep air pollutants at bay, no matter how you like your chicken nuggets.

“Continuing to ventilate, or keeping extractor fans turned on for a period of time will really help to avoid the buildup of this indoor pollution,” he said, “and reduce the potential for the pollutants to be transported and distributed throughout the house with the associated higher personal exposures.”

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Header image courtesy of I Am R (CC BY 2.0)