The effectiveness of Local Exhaust Ventilation (LEV) in capturing vapors generated was evaluated using a drum-filling operation as an example. The experiment consisted of measuring the effectiveness of three LEV systems (a canopy hood, a slot hood, and a lay-on hood). It was found that when operated at the ACGIH design flow rates, the hoods were highly effective in capturing emissions from drum-filling operation. Capture efficiencies for canopy hoods ranged from 93 to 100 percent based on total emission from the drum; for the slot hood and the lay-on hood capture efficiencies were determined to be 95 to 100 percent and 100 percent, respectively. In general, it was found the efficiency of an LEV system for a drum-filling operation is independent of the concentration of emission leaving the drum. The drum fill rate, which determines emission velocity at the drum bung hole, has been shown to affect LEV efficiency for the slot hood used in the study.