Biosafety Cabinets (BSCs) and Biological Safety Levels (BSLs): Breaking Down the Differences
What is a BSL?
Biological Safety Level (BSL) is a biocontainment designation developed by the American Biological Safety Association (ABSA) to protect personnel from exposure to harmful, potentially pathogenic microbes in a research or manufacturing environment.
What differentiates BSL designations from one another?
In the United States, the Center for Disease Control specified four general Biosafety Levels, adopted from the ABSA designations. Each increasing BSL corresponds to greater risk, building upon the previous level to provide greater protection.
BSL-1: for work with well-characterized microbes that do not present a serious health risk, such as laboratory strains of E. coli. This designation does not require engineering controls (i.e. a biosafety cabinet) and can be carried out on the bench with minimal personal protective equipment.
BSL-2: for work with moderately hazardous microbes known to cause infectious diseases in humans. An example of this would be Staphylococcus aureus. This level requires the use of a biological safety cabinet with negative-pressure containment, and exhausted air must be filtered prior to release.
BSL-3: for work with potentially lethal microbes that are easily aerosolized, such Mycobacterium tuberculosis. This level requires restricted access to the work environment, immunization of personnel (where available), and the use of respirators. Work must be performed in a primary engineering control such as a biosafety cabinet, and air must be filtered before it can be exhausted.
BSL-4: for work with high-risk, airborne pathogens that frequently cause lethal infections, such as Ebola. Requires all work to be carried out in a Class III BSC. In addition, personnel must use full-body, positive-pressure cleanroom suits. All materials must be decontaminated prior to leaving the BSC.
Which BSC is appropriate to which BSL?
Biological safety cabinets were designed to provide localized protection from potentially biohazardous substances. In general, the BSL level corresponds to BSC class, indicating the BSC type most appropriate for each BSL application. The National Science Foundation designates three classes for BSCs:
Class I: a negative-pressure hood in which air is drawn from the room into the enclosure and subsequently exhausted after treatment with UV-C germicidal light and HEPA filtration. These enclosures protect personnel, but do not protect products within the hood.
Class II: protect both operator and product. These units provide a HEPA-filtered laminar flow of air to protect the product from contamination, much like a laminar flow hood. Air is then directed into negative pressure plenums where it can be re-filtered or exhausted into a ducting system. Four common types of Class II BSCs are distinguished by air velocity as well as the percentage of air that recycled versus exhausted.
Type A1 (formerly Type A): minimum inflow velocity of 75 ft/min. 70% of air is recirculated; 30% is ducted. The contaminated plenum is surrounded by the lab environment.
Type A2 (formerly Type A/B3): minimum inflow velocity of 100 ft/min., with a negative plenum surrounding the contaminated plenum. 70% of air is recirculated; 30% is ducted.
Types B1 and B2 have dedicated hard-ducted exhaust lines, with 70% air exhaust in Type B1 and 100% air exhaust in Type B2.
Class III: provide the highest level of protection when working with high-risk pathogens. These enclosures are gloveboxes with airtight seals. Operators use glove ports to manipulate materials within the enclosure, never coming into direct contact with any materials. Exhaust air is HEPA filtered and directed into a ducting system.
BSCs, BSLs, and ISO Classes
When it comes to working with hazardous or potentially infectious material, protecting personnel must be the primary concern. However, offering personnel protection does not have to come at the cost of risking product integrity. Class II BSCs provide protection to both personnel and product simultaneously. They provide an ISO class 5 clean environment for product manipulation, while ensuring that exhaust air is filtered and ducted out of the environment. Thus, a class II BSC is the ideal solution when working with moderately hazardous material and both personnel and product safety are required.
Protects users, products and environments from hazardous agents that require Biosafety Level 1, 2 or 3 containment. Dedicated exhaust system and remote blower discharge 100% of filtered exhaust air. Suitable for use with hazardous chemicals and fumes.
Class II C1
Toggle between A2 and B2 configurations. Protects personnel, product and lab environment by maintaining complete containment in event of exhaust system failure. For Biosafety Level (BSL) 1, 2, and 3 containment or BSL 4 with PPE
Ergonomic Purifier Axiom units convert between Type A and Type B Mode for use in BSL 1,2 and 3 labs; available in 4 ft. and 6 ft. models with sash openings of 8” and 10”
Purifier Logic+
Purifier Logic+ discharges 100% of filtered exhaust air from work area via a dedicated exhaust system and remote blower; models need to be hard ducted to the outside
Labconco Purifier Logic+ Class II B2 Biological Safety Cabinets
Unit Dimensions 4': 54.3"w x 31.2"d x 72.6"h (1379.22 x 792.48 x 1844.04 mm) 6': 78.3"w x 31.2"d x 100.1-106.1"h (1988.82 x 792.48 x 2542.54-2694.94 mm)
Material Stainless steel inlet grille with Reserve-Air™ Secondary Airflow Slots*; removable, seamless type 304 stainless steel, dished work surface with lift out knobs; powder-coated steel exterior
Electrical 115 volts, 60 Hz, 12 amps, Domestic 230 volts, 50/60 Hz, 8 amps, North America
Compliance NSF International and ETL Listed; meets Class 5 conditions per ISO 14644-1 and 2 (formerly Class 100)
Critical Environment Solutions
Terra's mission is to help customers in highly regulated industries transform the world with critical environment solutions that improve health, safety, performance, and yields. These environments may comply with stringent UL, ISO, IEST, ASTM and OSHA standards and local requirements.
Counterweighted, Anti-Racking Sash
The sash is angled at 10° for improved ergonomics without introducing glare. During operation, an alarm will be activated if the sash is opened too far, compromising airflow.
ADA-Compliant Touchpad Controls
The touchpad controls, mounted on the right-hand side of the hood, allow operators to manually toggle the blowers, lights, and power receptacles.
Inclined, Ergonomic Inlet Grille
The curved inlet grille provides comfortable support for the operator’s forearms while working within the hood. The airflow inlet pattern is designed to compensate for any airflow restrictions caused by the operator blocking the slots.
Class II B2 Biosafety Cabinets
Labconco Purifier Logic+ Type B2 Biosafety Cabinet Airflow Animation
Biological Safety Cabinets
Labconco Purifier Logic+ Type B2 Biosafety Cabinet uses an integral blower system to provide the utmost safety for the operator, meeting biosafety standards | 3651-60 displayedLabconco Purifier Logic+ Type B2 Biosafety Cabinet Airflow AnimationThis biosafety cabinet comes with an integral blower system to filter the air using HEPA filters, protecting the operator with negative pressure drawing room air in and ensuring containment.
Hoods designed for both clean processing and containment of the exhaust air; includes Class I and II, Types A and B, and a unique Type C from Labconco | 3642-10 displayedBiological Safety CabinetsHoods designed for both clean processing and containment of the exhaust air; includes Class I and II, Types A and B, and a unique Type C from Labconco.