The requirements for the design and operation of efficient fumecupboards and of their associated ventilation systems in universities, research establishments and industrial laboratories is reviewed. Particular attention is paid to the development of aerodynamic and other safety features, including the resistance to chemical attack of the working chamber, and to the siting of the fumehood within the laboratory. Practical experience gained over the past twenty years in the design of extract systems and fume-dispersal arrangements are described with particular reference to rate of extraction, duct materials, noise and discharge terminations. Current concern over methods of measuring fumehood contaminant and over energy conservation are also mentioned.