Qualitative and Quantitative Analysis of the Air Pollutants Emitted from Commercial Kitchens  

Project Title: Qualitative and Quantitative Analysis of the Air Pollutants Emitted from Commercial Kitchens

Applicant: Hong Kong University of Science & Technology

Total Approved Grant: $678,757.74

Duration: 1/1/2002 - 30/6/2003

Project Status/Remarks: Completed

Scope:

To study the characteristics of air pollutants emitted from commercial kitchens and develop a comprehensive database of the common air pollutants. It involves quantification of the performance filter installed for air exhaust ducts, characterization of air pollutants, and development of a procedure to step up the pollution control in kitchens. Field survey and chemical analysis of air pollutants would be conducted. It is expected that the results of the project would lead to better understanding of the chemical composition and physical behaviour of the organic emissions released from commercial kitchens, which could serve as a reference for EPD and pollution control equipment manufacturers for future design of effective pollution control equipments.

Summary of the Findings/Outcomes:

Analytical methods for the identification of organic pollutants, aliphatic hydrocarbon (AHs), polyaromatic hydrocarbons (PAHs), free fatty acids (FAs), glycerides (GYs), carbonyl compounds, cholesterol and aromatic amines (AAs) in cooking fume were developed. Air samples of the cooking fumes from twenty typical commercial kitchens were collected and quantified. Fatty organic including free fatty acids and glycerides were the major contributor of the organic emissions with the predominance of C16 and C18 of saturated and unsaturated fatty acids components.
Among the twenty restaurants, both gas and particulate distribution of AHs, PAHs, FAs and GYs were also presented. All the above compounds in general follow the partitioning rule, i.e. low molecular weight compounds with high vapour pressure were predominantly found in the denuder whereas high molecular weight compound with low vapour pressure were mainly existed in particulate phase. Relatively high concentration of carcinogen, aromatic amines, was found in frying rice vermicelli with beef, one type of Chinese dishes. Although aromatic amines have been implicated as human bladder carcinogens, their exposure limit is still unknown. Further toxicological study can be done on cooking fume emitted from different kinds of restaurants so as to recommend the exposure limit.
The emission rate of cooking fume per dishes from Chinese restaurants was estimated. This information will be useful in predicting the contribution of cooking fume from commercial restaurants to atmosphere organic aerosol.