Choosing Between A Biosafety Cabinet vs. Fume Hood vs. Laminar Flow Hood
While all are designed to provide protection, there are key differences in the uses for biosafety cabinets, fume hoods and laminar flow hoods. Here is a brief look into each of the three laboratory staples as well as factors to consider when deciding which system best fits the task at hand.
A biosafety cabinet (BSC) is a ventilated enclosure designed to protect the user, environment and research materials. It is used for various applications in research settings. Standard uses include handling human or animal tissue, human gene studies, pathogen micro-organisms, genetically modified micro-organisms, and recombinant DNA.
A BSC utilizes a filtration exhaust system equipped with high-efficiency particulate air (HEPA) filters. The system works to trap pathogens, biohazards and other potentially infectious agents before discharging microbe-free exhaust air back into the lab. BSCs provide a clean work environment and adequate containment without requiring installation of exhaust ductwork and ventilation.
Fume hoods, on the other hand, are commonly connected to the building’s plumbing and mechanical HVAC system to exhaust the air outside. The contaminated air is cleaned via HEPA filters contained in the fume hoods or is treated by the building’s exhaust system. There are ductless hoods similar to BSCs that also use HEPA filtration and recirculate air into the lab.
Fume hoods are designed to deliver airflow away from the user and to the work area continuously. The intent is to capture, remove and direct fumes away from the work area. While this protects the user, it does not provide protection for the product. Fume hoods are commonly used to handle aerosols, carcinogens, flammables, odorous materials and other toxic, reactive or volatile elements. The workspace can be somewhat turbulent and is not suited for the handling and manipulation of pathogenic agents.
Conversely, laminar flow hoods — also known as clean benches — provide a sterile environment with minimal turbulence. This makes them ideal in situations requiring utmost contamination control or when using small utensils and equipment. However, they only protect the product and not the user. There are two configurations for laminar flow hoods: vertical and horizontal. Each setup is best-suited to specific applications respectively and can offer various benefits depending on use.
Laminar flow hoods serve a variety of functions in the medical, pharmaceutical, manufacturing and scientific research fields. Filtration can vary by model. Some do not have filtration while others discharge HEPA-filtered air from the back or top of the cabinet across the work surface and toward the user. As such, these should never be used when controlling infectious materials, cell culture materials, drug formulations or any other potentially hazardous materials.
Because of stark differences such as these and more, proper training is needed for all three pieces of equipment. For a side-by-side comparison of biosafety cabinets, fume hoods and laminar flow hoods, please see the accompanying resource.