Fume Cupboards and Biosafety Cabinets: Explained
What is a fume cupboard?
Fume cupboards, also known as fume closets, are local ventilation devices designed to limit exposure to airborne contaminants. This includes toxic, offensive, or flammable vapours, gases and aerosols and dust. They rely on extraction and can be ducted to the outside or recirculated. Airflow of the cupboard can be affected by: design, size of the window opening, type of process and substance being controlled.
How to use them
When installing your fume cupboard, it is important to know the regulatory standards as outlined in BS EN 14175. Most importantly when placing your fume cupboard, it should be away from windows, doors and walkways that could interfere with the ventilation system.
When choosing what type of fume cupboard, you should consider:
- The type of work undertaken
- Chemicals used
- Flexibility – will your application and chemical use remain constant?
Ducted or recirculating?
Conventional ducted fume cupboards connect to facility ductwork, removing contaminated air to outside the facility. Recirculating fume cupboards are stand-alone units that filter contaminated air and recirculate clean air back into the room.
Ducted fume cupboards: pros and cons
- Safer for lab workers
- Can handle a wide range of chemicals
- Easy to operate and maintain
- Exhaust system keeps contamination outside of the lab
- More expensive
- More difficult to install, requires planning permission
- Stationary in the lab – no flexibility
- Uses more energy
Recirculating fume cupboards: pros and cons
- Less expensive
- Easy to install
- Mobile in the lab – flexibility
- Uses less energy
- Handles limited chemicals
- Need to replace filters regularly
- Not as effective at removing contaminants
- Not designed for constant use
What is a biosafety cabinet?
Biosafety cabinet or BSC is a type of biocontainment equipment used in biological laboratories to provide personnel, environmental and product protection. Most use high efficiency particulate air (HEPA) filters. There are several different designs of biosafety cabinets that offer different levels of protection to the worker and the product.
How to use them
When installing your biosafety cabinet, it is important to know the regulatory standards as outlined in BS 5726:2005. Most importantly, the BSC should be placed out of the laboratory personnel traffic pattern and away from entryways. There should be 1000 mm of undisturbed space in front of the sash of the BSC, 150 mm of space either side and 1500 mm from opposing bench tops.
When choosing your BSC, you should consider:
- The type of biological hazard you are handling.
- The level of protection needed – do you need to protect just the operator, or do you also need to protect the product/item being handled?
This will determine the class of cabinet you require.
Classes of BSCs:
A class l cabinet is used for personnel and environmental protection. Class l cabinets do not offer product protection from contamination. They pull room air through the front, away from the operator.
A class ll cabinet is used for personnel, product, and environmental protection. These are often referred to as cell culture or tissue culture hoods. Class ll cabinets are further subdivided into types A1, A2, 1, B2 and C1.
A class lll cabinet is a totally enclosed, ventilated cabinet with leak-tight construction and attached rubber gloves for performing operations inside the cabinet. It has a transfer chamber with interlocked doors that allow sterilisation of materials before entering/exiting the glove box. The cabinet is maintained under negative pressure, and the supply air is drawn through HEPA filtration. The exhaust air is treated with either double or single HEPA filtration, followed by incineration.
The difference between BSC’s and fume cupboards
Both are specialised types of laboratory equipment. While they look similar, and both protect from hazards their function and operation differ.
A fume cupboard is used for dangerous chemicals, and does not use HEPA filters. Fume cupboards often exhaust to the outside. A BSC is used for biological agents and must use HEPA filtration. BSCs are often recirculating and can also be exhausted to the outside but requires decontamination.
Fume hood protects the user, while the biosafety cabinet protects the user, the environment, and the material.
At Bulb, we are happy to assist with your bespoke laboratory design, process flow, equipment selection and placement to achieve required compliance. Get in touch today at or 0118 988 9200