Chemical Fume Hoods

A chemical fume hood is an enclosure that enables technicians and scientists to work with hazardous chemicals without risk of exposure to the fumes they produce. Users sit or stand in front of the unit and work with the chemicals inside the enclosure. A blower at the top of the unit draws the air inside the unit away from the user, protecting them from any fumes generated by the chemicals.

There are two main categories of chemical fume hoods:

• Ducted Chemical Fume Hoods: These are connected to an exhaust system built into the laboratory. As the air is drawn out of the enclosure, it passes into the exhaust system where it is vented outside the building safely so there is no risk of exposure to anyone inside or outside of the lab. This is the most common type of fume hood, but it requires existing infrastructure or renovations to the lab space to accommodate the exhaust system.
• Ductless Chemical Fume Hoods: Also known as filtered fume hoods, these units don’t feature any exhaust connections. Instead, the contaminated air is drawn into the top of the unit, where advanced filtration technology is used to capture any contaminants and remove them from the air before it is released back into the lab environment. These units are the best choice in labs where there is no exhaust system or in situations where energy conservation is a priority. However, they also require more maintenance than ducted fume hoods, including regular replacement of the filters.

Chemical fume hoods of both types come in a wide range of form factors. They can be either freestanding floor-mounted designs or benchtop models that can be installed onto existing countertop space. In some cases, labs require specialized fume hoods for dealing with exceptionally challenging or hazardous chemicals such as perchloric acid or those used in acid digestion processes.