.png)
%20Standard.webp)
%20%26%20Metabolites%20Standard.jpeg)
%20Standards.png)
Biosafety Cabinet Types: Selection Criteria and Applications
In biohazard laboratories, the biological safety cabinet (BSC) acts as the primary defense for the operator, the environment, and the work product. These containment systems are categorized into three classes, Class I, II, and III, defined by their distinct airflow patterns and performance capabilities.
Since the specific class determines which biological agents and chemical hazards a facility can support, selecting the correct model is a fundamental requirement for maintaining laboratory safety standards.
Class I
Class I BSC provides basic containment. They operate by pulling room air inward through the front opening, flowing it across the work surface, and passing it through a HEPA filter before exhausting it.
While this inward airflow effectively safeguards the operator and the immediate environment from aerosols, it continuously exposes the work surface to unfiltered room air. As a result, Class I biosafety cabinets do not protect the sample or product and are suitable only for low-to-moderate risk agents where sample sterility is not a priority.
Class II
The biosafety cabinet Class 2 is the industry standard for modern biomedical research. Different from the Class I models, Class II biosafety cabinets protect both the operator and the product.
This type of biosafety cabinet establishes sterile work zones using HEPA-filtered vertical laminar airflow. By creating an internal air curtain, the system effectively safeguards samples against airborne particulates and cross-contamination.
To address specific laboratory requirements, the Class II category is further divided into four primary subtypes:
1. Class II, Type A2
The Class II, Type A2 stands as the most widely used biosafety cabinet type globally. An improvement upon the obsolete Type A1, this unit recirculates approximately 70% of HEPA-filtered air back into the work zone while exhausting the remaining 30%.
Due to this efficient design, laboratories favor the Class II, Type A2 for its versatility and cost-effectiveness. It provides a reliable sterile environment for standard microbiological agents (BSL-1 or BSL-2), making it the go-to solution for general life science applications that do not involve volatile toxic chemicals.
2. Class II, Type B1
For workflows involving hazardous chemicals, the Class II, Type B1 provides a distinct operational advantage. Unlike the A2 model, this cabinet exhausts approximately 70% of its air through a dedicated external duct system and recirculates only 30% back into the work zone.
Because the exhaust is drawn directly from the rear of the cabinet, where vapors accumulate, the B1 is ideal for procedures involving volatile chemicals or radionuclides that require active removal from the laboratory.
3. Class II, Type B2
When safety protocols demand zero recirculation, the Class II, Type B2 provides the necessary containment. This unit is a "total exhaust" cabinet that extracts air from the room and exhausts 100% of it to the outside through a hard-ducted connection.
Because no air is recirculated within the work zone, the B2 effectively eliminates the risk of vapor buildup. This capability makes it the mandatory choice for high-hazard work involving toxic chemicals, volatile radionuclides, and biological agents.
4. Class II, Type C1
The Class II, Type C1 bridges the operational gap between A2 and B2 models, offering a new standard in flexible containment. Uniquely designed for adaptability, it can operate in a recirculating mode for standard biological work or connect to an exhaust system for single-pass operation.
This versatility allows facilities to adjust their equipment as research priorities shift, maximizing utility and eliminating the need for new capital investments when protocols change.
Class III
The biosafety cabinet Class 3 provides the highest level of containment available. Often described as a glove box, this biosafety cabinet is a fully enclosed, gas-tight vessel that physically separates the operator from the work by a solid barrier. Manipulation of samples occurs strictly through heavy-duty, arm-length rubber gloves attached to the cabinet.
Designed for the highest-risk environments, Class III biosafety cabinets are used for BSL-4 agents that pose lethal threats. To eliminate any risk of exposure and guarantee zero leakage, the enclosure is maintained under negative pressure, with all airflow passing through double HEPA filtration or incineration.
Secure Your Research with IT Tech
Distinguishing the specific capabilities of the 3 classes of BSCs and their subtypes is vital to ensuring laboratory safety and regulatory compliance. Otherwise, a mismatch in equipment selection can leave your staff vulnerable to exposure or your samples open to contamination. For a detailed breakdown of these specifications, refer to our biosafety cabinet guide.
As a lab equipment supplier in Singapore, IT Tech offers a complete, high-quality range of containment solutions. We provide end-to-end expertise, helping you identify the exact classification, whether A2, B2, or C1, based on your specific agents and workflow requirements. This ensures your infrastructure safeguards your team and supports the principles for a compliant and reliable lab.
Contact us today to secure your research environment.
Products You may Like
Check out other IT- Tech product that suit your taste
Subscribe to our newsletter
Stay updated with IT-Tech Insights
Related posts
Check out other IT- Tech Scientific Resources
