WHAT IS A BIOSAFETY CABINET?
Class I biosafety cabinets rely solely on a minimum of 75 fpm [0.38 m/s] inward airflow velocity for personnel protection.
Class II BSCs provide product, personnel, and environmental protection by combining unidirectional downward airflow
with a dynamic air barrier. Within class II, there are several different types based on which portions of the work zone
are recirculated and/or exhausted, as depicted above. Class III, usually installed in maximum containment laboratories,
are specifically designed to work with Biosafety Level 4 (BSL-4) pathogens and maintains a physical barrier between
personnel and their products. Roughly 90% of all biological safety cabinets installed globally are Class II, Type A2.
Class I
(100% Exhausted)
Class II Type A2
(70% Recirculated / 30% Exhausted)
Class II Type B1
(30% Recirculated / 70% Exhausted)
Class II Type B2
(100% Exhausted)
Contaminated
Room Air
Contaminated
Work Zone Air
HEPA-Filtered
Exhausted Air
HEPA-Filtered
Downflow Air
Exhausted Area
of Work Zone
A Biosafety Cabinet (BSC) is an enclosed laboratory
workspace for safely handling potentially contaminated
or other hazardous materials requiring a predefined
level of biosafety. By combining unidirectional airflow
from the top of the workspace with air inflow from the
room, a biosafey cabinet maintains a dynamic air barri-
er that protects scientific personnel and their products
from outside contamination. Several different classes of
biosafety cabinets exist, defined by the varying degrees
of bio-containment required. Several types exist within
those classes, dictated by how much of the air passing
through the work zone is exhausted or recirculated. All
cabinets utilize High Efficiency Particulate Air (HEPA) or
Ultra Low Particulate Air (ULPA) filters to maintain an
aseptic environment within the workspace.
A BSC must supply the necessary level of safety at an
affordable cost of ownership. Meeting those criteria as
effectively as possible depends on the cabinet’s design
and components. NuAire’s unique HEPEXTM Zero Leak
Airflow system evenly disperses downflow air across the
supply filter, minimizes vibration transfer, and eliminates
potential leaks by surrounding the positive pressure ple-
num with negatively pressurized chambers. Reinforced
by NIH guidelines, NuAire’s ultra-high efficiency DC ECM
motor offers improved reliability and safety by utilizing
a single control point to regulate both air down-flow and
inflow when compared to a dual-motor system. The DC
ECM motor also automatically adjusts its speed to main-
tain consistent airflow settings based on readings from
the on-board Electronic Control System (ECS).
Classes & Types of Biosafety Cabinets
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