Fume cupboards are only made for protection of workers from hazardous chemicals, not from biohazardous materials in a laboratory environment. For protection from biohazardous materials, only biosafety cabinets are suitable and therefore in no way should be interchangeable.
Fume hoods are designed in a way that purifies the air when it wafts through them. In case chemicals are present in the air, workers remain unharmed as their bodies are protected.
A typical fume hood is an enclosed cupboard. It has a ventilation system and a sash, which is made of glass, is placed in front of the cupboard to allow users’ access inside the hood. Sashes can be placed in any way but in no way are to be removed inside the laboratory.
For some radioactive materials, there are purpose-made fume hoods. Workers have to wear these special hoods when they are in a biochemical laboratory environment. These hoods are generally taken off just near the laboratory, and are not exposed to an outside environment.
The ventilation system inside the hoods works continuously. It collects any hazardous chemicals in the air inside the laboratory environment and ventilates them in the outside environment. Since their concentration in the outside environment is broken, their presence in the environment does not pose any risk to workers or other people.
Fume hoods have to be checked for safety regularly and if any of the cupboards does not meet the minimum safety standard it has to be disposed of immediately. Also, all the laboratory equipment should be kept at least six inches inside the hood.
Using fume hoods is not a necessity in all your experiments. You can ascertain if you require a fume hood by carrying out a hazard analysis which should include review of physical characteristics of the material to be used in the experiment, the volatility of the material present and probability of their release and some other factors.