Abstract: A fume hood having a step baffle system that improves uniformity of flow under different operating conditions, increases draw along the work surface, and, in general, enhances hood performance. An intermediate baffle plate of the baffle system may be pivotally mounted and may be associated with a remote-control mechanism for adjusting its operating position. A rectangular bellmouth collar at the exhaust opening of the hood contributes in achieving a high level of hood efficiency and permits nearly vertical orientation of the fixed uppermost baffle plate, thereby providing greater work space within the upper portion of the hood chamber. Exhaust ports at the top corners of the upper baffle plate promote and control the vertical flow of gases in the upper portion of the hood chamber to aid in the evacuation of fumes from that region.