When buying a fume cabinet – also known as a fume hood or fume cupboard, there are a number of considerations to keep in mind. The main guiding question, however, is what you will be doing with the fume cabinet – what do you need it for? There are various types on the market – and the first step in purchasing one is to conduct a comprehensive risk assessment of your workplace and work operations. This will tell you what fume cabinet best suits your needs. In this article, we provide an overview of what you’ll need to know, to make the purchasing process easier.
A fume cabinet, primarily used for containing chemicals, is a box-like ventilation device with a sash window. It provides partial containment of chemical fumes, vapors and gases, as well as particulate matter, preventing exposure and guarding personnel against spills, fires and other reactions. A fume cabinet works in one of two ways. Some draw air in from the laboratory and exhaust the diluted fumes outside into the environment where they are safely dispersed. Others release the air back into the laboratory after it has been sufficiently filtered.
Based on the above, fume cabinets can be divided into ducted and ductless, or recirculating, types. Ducted options comprise the bulk of fume cabinets globally, and exhaust the air outside.
When choosing a ducted type FEC, keep in mind that these units need a special type of extractor fan capable of handling the VOC’s present in the FEC chamber. Ductless fume cabinets, on the other hand, circulate the air back into the laboratory. Ductless fume cabinets, which have lower initial costs, cannot be used for the manipulation of hazardous materials, but are useful in educational contexts, or to work with odiferous but non-harmful substances.
Ducted fume cabinets can be further divided into a wide range of sub-types. These include cabinets with constant air volume, ones with variable air volume, and low-flow cabinets that have lower than normal extraction face velocity, making them cheaper to run and energy efficient. As a fume cabinet is a long-term investment that will likely last decades, energy efficiency is something that should be taken into account when deciding what to purchase.
There are several adaptations of fume cabinets. Some are fitted with wash-down facilities, others are walk-in, some are floor mounted while others are designed to be fitted on work benches, and there are special variations for working with strong acids or radioactive materials. The product being worked with dictates the type of fume cabinet that is selected.
If you are working with chemical substances, a fume cabinet will likely provide adequate levels of protection for your work needs. If you are manipulating harmful micro-organisms, higher and different levels of protection will be required – and you may need to consider a biosafety cabinet Class I instead. Biosafety cabinets are equipped with HEPA filters and offer much greater exposure prevention than fume cabinets.
Other considerations when purchasing a fume extraction cabinet include the positioning and installation in the workplace, as well as how and where the ducting will be fitted to the outside of the building. The cabinet should have good lighting and be located away from draughts. Also, a maintenance schedule is essential in going forward to ensure the continued efficacy of the cabinet with regular validation tests carried out to prove compliance with your regulating authority
