Ethanol emission factors for glazing during candy production.

This study determined emission rates of ethyl alcohol from a candy glazing operation and, from observation of source activities, expressed these emission rates as emission factors. A mass balance modeling approach was used in conjunction with on-site field testing. The candy was processed in a row of 24 rotating open-faced pans, each with a capacity of approximately 250 lb candy/batch. Twelve 1-hour periods were monitored during production over two days. Ethanol vapor samples were collected on charcoal tubes simultaneously at four locations at different distances from the pan line. Continuous monitoring also was carried out at one location with a gas analyzer. The tube samples were analyzed by gas chromatography. Ventilation measurements and source activity observations were collected at the same time as the gas samples. The average concentration 1.5 m in front of the line was above 1000 ppm. Average emission rates for 12 one-hour periods, determined from the concentration measurements and three different forms of the ethanol mass balance around the space, were 38.4 kg/hour, 42.5 kg/hour, and 49.6 kg/hour. When emission rates were compared with the number of batches the resulting emission factors were 500 g/batch, 291 g/batch, and 453 g/batch, respectively. These values were in good agreement with the estimate of 446 g/batch developed from the glaze mixture composition and the approximate amount of glaze mixture added to each batch. Testing using the emission factor approach removes the effect of the particular interior space in which the data are collected and reproduces changes in emissions and exposures.