What are safety cabinets and where should a specific type of safety cabinet be used in school science laboratories? There are several different types of safety cabinets, each having a specific use. There are those for protecting science students from inhalation of poisonous dust clouds or gases, and venting those gases harmlessly away. Others are designed to protect teachers and students by containing accidental chemical spills; and there are those designed for safely storing the more dangerous chemicals. Let's take a look at some of the variations to be found in school labs and their specific purposes. The best-known type of safety cabinet, and the one that all one-time science students will be familiar with, is the fume cupboard. Many an errant experiment with noxious chemicals resulted in a whoosh of pungent, and in some cases lethal, gases gushing forth from a glass beaker, which was quickly dealt with by placing the whole dangerous mess into a fume cabinet and swiftly closing the glass door. There are two main varieties of fume cabinet in popular use, namely the ducted and ductless types. Ducted safety cabinets vent gases outside the building directly into the atmosphere via a large diameter plastic (uPVC) duct. There are also instances where. for low volume or low toxicity work. the fumes can be absorbed into special carbon filters and then vented back into the laboratory. These cabinets are generally composed of either glass reinforced plastic or painted metal, depending on what they will be used for, with glass fronts and sometimes sides for good all round viewing. Ductless safety cabinets, otherwise known as recirculating fume cupboards, are fitted with carbon filters of varying compositions intended to match the use to which they will be put. They are not recommended as a direct replacement for ducted fume cupboards, but to be used alongside them where less toxic or dangerous chemicals will require containment. They generally vent the filtered and rendered harmless gases back into the laboratory and are of similar composition to the ducted variety. Another type of safety cabinet used in school laboratories is the powder cabinet. These are used when mixing and weighing chemical powders while preventing possibly toxic dust clouds from powder spills from endangering students or teachers. They work by utilising an inward airflow system to remove any dust spillage and protection shield in the case of powder weighing, to prevent unwanted disturbance of the powder. Safety storage cabinets come in many different types, depending on the kinds of chemicals to be stored in them. Most school labs have standard metal lockable safety storage cabinets to store less volatile chemicals, along with vented and filtered cabinets for the more dangerous chemicals. Vented storage cabinets have similar fan assisted carbon filtration systems to those found in ductless fume cupboards, to eliminate noxious vapours that might be emitted from some less tightly secured chemical containers. These are some of the more popular safety cabinets found in most school science labs, from the ducted and ductless fume cupboards used in the more potentially dangerous experiments to the powder cabinets used for mixing, proportioning and weighing of chemical powders and the safety storage cabinets for the safe storage of all chemicals used in those laboratories.