A fume hood, also called a fume cupboard, or colloquially just a "hood," is a critical piece of safety equipment in any chemistry laboratory, designed to ensure proper ventilation of hazardous fumes. The fume hood is generally a large working area in which chemical reagents can be placed. A constant air flow is created through the device, usually using fans, exhausting air through the top of the fume hood and out of the building. If the hood is working properly, most or all of the vapors from any chemical reagents placed in the hood will be exhausted from the laboratory area, thus reducing the health risk to the laboratory technicians.

To determine whether a chemical is likely to require a fume hood for safe usage, its material safety data sheet (MSDS) should be consulted. If there is doubt, use a hood.

Warning

Even though a properly functioning fume hood provides adequate ventilation be sure not to smell any chemicals directly even when using one. Doing this could cause severe damage to your trachea and your lungs. Use the proper technique of taking your palm and waving it above the test tube or beaker to waft reduced amounts of the substance towards your nose.