Kitchen hood performance in food service operations

Cooking processes at food service operations release fumes that present risks of food contamination, fire, and employee exposure to hazardous chemicals. Local exhaust ventilation in the form of kitchen hoods is commonly used to control these risks. State codes often refer to the need for adequate ventilation, but hoods are not an explicit point on most inspection sheets and are rarely quantitatively assessed to determine if flow rates meet recommended levels. For this article, the flow rates of 89 hoods in 60 restaurants were measured and compared with appropriate flow rate guidelines. It was found that 39 percent of the hoods met the guidelines of the American Conference of Governmental Industrial Hygienists and 24 percent met the guidelines of the American Society of Heating, Refrigerating and Air-Conditioning Engineers. Inspecting sanitarians identified inadequate flow rates in less than 4 percent of the cases. Hoods used to control heavy-duty operations such as upright broilers, charbroilers, and woks had the lowest pass rate, 18 percent. The researchers also graded the hoods in terms of cleanliness. These ratings did not correlate with hood cleanliness notes on the sanitarians' inspection reports. Overall risks from cooking fumes could be reduced by regular systematic inspections of kitchen hoods, with hoods perhaps included as an independent item on inspection sheets. Quantitative assessment of flow rates is time consuming and is probably not feasible for all inspections. Periodic inspections of hoods on heavy-duty operations could be a workable way to reduce risks.