Walk-in fume hoods are basically floor mounted units where the floor itself is considered as a working surface. Walk-in fume hood is used for tall assemblies or large apparatus like kilo scale – High volume reactions etc. Sometimes it may be used as for a storage of containers that is prone to some hazard, but may not fit in to defined storage cabinet. Generally, it has horizontal sliding sash, although some models are equipped with telescopic vertical sliding sashes. For safety reasons, horizontal sliding sashes are always recommended in walk-in fume hoods.
The term ‘walk-in’ is hinted that a person can walk-in to the hood. In fact, the word ‘walk-in fume hood’ is misleading. So far, the safety precaution is concerned in the laboratory, the hood must never be entered during the experiment or fume generation inside the enclosure. Because of large opening area at front fascia, it is advised not to use floor mounted fume hoods for experiments that generate highly toxic fumes or poisonous gas. It is recommended that only one sash be fully opened during hood operation.