Quantification of Volatile Organic Compounds (VOCs), Nitrogen Oxides (NO x ), and Ultrafine Particles (UFPs) Emitted by Domestic Air Fryers: A Chamber Study of Indoor Air Quality Impacts

High Resolution Image Download MS PowerPoint Slide Air frying has emerged as a popular low-oil cooking method, yet its impact on indoor air pollutant emissions remains insufficiently understood. In our study, emissions of volatile organic compounds (VOCs), nitrogen oxides (NO x ), and ultrafine particles (UFPs) were measured during the air frying of 12 different dishes within a ca. 0.15 m 3 Perspex chamber. Pollutant emissions varied significantly depending on the food type, with rates in the ranges of 17.8–184.0 μg min –1 for total cooking VOCs, 24.6–37.9 μg min –1 for NO x, and 0.1–17.4 × 10 12 # min –1 for UFPs, primarily due to Maillard reactions and lipid thermal decomposition. While pollutant concentrations and ozone formation potentials were elevated within the chamber, scaling to the volume of a small kitchen indicated substantially lower levels compared to conventional frying methods. Notably, only high-fat foods produced UFP concentrations comparable to those of deep frying. No NO x emissions were found during blank (empty appliance) runs, and NO x was only detectable while cooking certain types of foods. However, residues accumulating within inaccessible areas of the air fryer following over 70 uses led to increases of 23% in VOC and 236% in UFP concentrations while not cooking food.