British Standard 476. These are cabinets which are fitted with forced ventilation. They may be free-standing with their own extract system, or may be situated beneath a fumecupboard and attached to its duct. These are not designed as storage areas and they should be kept clear of materials and containers when these are not needed for the ongoing operational work. As in all work areas, clutter should be kept to a minimum.
Materials stored in fumecupboards also disrupt the air-flow making the fumecupboard less efficient.
Acids Small quantities can be stored safely inside a vented cabinet or even in a wooden cupboard so long as they are in a containment tray to contain any spillages. Consideration must also be given to the effects of any acid fumes on any metal in the fittings and construction of the container. Acid chlorides and other materials which liberate acid fumes can also be stored in a similar way. Alkalis are incompatible materials which must be stored separately. Alkalis Even although these materials are marked with a corrosive label, as are acids, they must be stored separately from acids since any accidental mixing of the concentrated materials will generate large quantities of heat and fumes.