Also known as a fume hood, fume extraction cabinets play an integral role in the health and safety standards in potentially hazardous environments.
Therefore, when making a choice between all the available fume extraction cabinets, it’s important to first establish what application it will be used for.
What is a fume cupboard used for?
Fume extraction cabinets (FEC) are primarily used to provide partial containment of chemical fumes, vapours and gases, as well as particulate matter.
In doing so, they are able to limit or prevent the operators’ exposure to harmful fumes as well as protection against spills, fires and other potentially fatal chemical reactions.
How does a fume hood work?
A fume cabinet works in one of two ways;
By drawing in air from the laboratory and exhausting the diluted fumes out into the environment where they are safely dispersed (ducted cabinet)
By releasing the clean air back into the laboratory after it has been sufficiently filtered (ductless cabinet)
Ducted Fume Extraction Cabinets
When choosing a ducted FEC, it’s important to remember that these units need a special type of extractor fan which is capable of handling the volatile organic compounds (VOC’s) which are being handled in the extraction chamber. Always note, the room housing the Fume Extraction Cabinet will be discharging air, and if air-conditioned this may affect the efficiency of the air conditioner.
Vivid Air offers a Make-up air system to compensate for discharged air thereby maintaining the room’s air change rate.
Ducted fume cabinets can be further divided into various sub-types. These include cabinets with:
Constant air volume
Variable air volume
Low-flow cabinets that have lower than normal extraction face velocity
Low-flow cabinets are cheaper to run and more energy efficient.
Because fume cabinets are long-term investments, energy efficiency is something that should be considered when deciding what type of FEC should be purchased.
Ductless fume cabinets circulate the air back into the laboratory. Although ductless fume cabinets have lower starting costs, they cannot be used for the manipulation of hazardous materials.
However, ductless FECs are useful in educational contexts, or to work with odoriferous substances (letting off an especially unpleasant odour) which are not harmful.
Types of Fume Extraction Cabinets
There are several adaptations of fume cabinets:
Fitted with wash-down facilities
Designed to be fitted on work benches
Furthermore, there are special variations for working with strong acids or radioactive materials.
Materials Used for FEC Inners
If you are working with chemical substances, a standard FEC should provide adequate levels of protection.
In environments where there is manipulation of harmful micro-organisms, a much higher level of protection will be required and can be provided by a biosafety cabinet Class I.
Biosafety cabinets are equipped with HEPA (high efficiency particulate air) filters and offer significantly less exposure to VOCs than a standard FEC.
Once again, the type of environment will determine which is the best material for the cabinet inner:
Stainless steel – offers heat resistance and durability, best for biohazard and radiochemical applications and is easier to decontaminate
Polypropylene – most widely used and considered the best material for most applications
Fibre Glass – best for use with corrosive mists and gases such as chlorine, hydro chloride, nitrogen oxides, ammonia, hydrogen sulphide
Vivid Air – Suppliers of Fume Extraction Cabinets
There are several considerations to make when selecting the appropriate fume extraction cabinet.
Positioning and installation in the workplace, as well as how and where the ducting will be fitted to the outside of the building are all factors to consider.
The cabinet should have adequate lighting and be placed far away from draughts.
Furthermore, a maintenance schedule is essential to ensure the continued functioning and efficacy of the cabinet and regular, controlled validation tests should be carried out in order to prove compliance with your relevant regulating authority and health and safety representatives.
For more information about our clean air equipment, including our HEPA filters and fume extraction cabinets, please contact us.