Measurements of Volatile Organic Compounds and Polycyclic Aromatic Hydrocarbons in 10 Commercial Kitchens

Commercial kitchens are often characterized by harsh working environments, which are linked to high staff turnover as evidenced by limited measurement data and anecdotal reports. These kitchens are energy-intensive, and equipment upgrades that improve indoor environmental conditions and lower energy costs may be possible. In 2024, we recruited 10 independently operated restaurants in California to participate in a week-long sampling study. Our goal was to assess indoor environmental quality, including thermal conditions and indoor air pollutant concentrations, and identify opportunities for energy-saving measures, such as improved kitchen ventilation and efficient cooking appliances. Here, we present a subset of the indoor air pollutant measurements, namely volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs), that were measured on one day during the week-long sampling period in each kitchen. In addition to VOCs and PAHs, our study also monitored other indoor air pollutants, such as ultrafine particles and nitrogen oxides, to capture the full range of indoor air pollutants present. VOCs and PAHs were measured in each kitchen near where most cooking activities occurred. Our results show sum of VOCs to range between 142 to 519 μg/m3, with a mean concentration of 277 μg/m3. Aldehyde, alcohol, terpenes, and ketone are the key groups of VOCsdetected, accounting for 46 to 88% (mean = 72%) of the total VOC concentrations measured. Aside from cooking related emissions, other sources of VOCs are evident from the presence of specific groups of VOCs found in some of our samples, such as siloxane from personal care products and glycol ethers likely associated with cleaning. The sum of 23 PAHs range between 19 to 1103 ng/m3, with a mean concentration of 378 ng/m3. Our results suggested higher PAHs in kitchens of larger restaurants with more cooking activities compared to the small establishments. While we are unable to draw conclusions about the levels of VOCs and PAHs with the design and performance of exhaust hoods, we noticed that in one of the kitchens with relatively higher PAHs, using an unlisted exhaust hood with low airflow rate is likely a contributing factor.