How Biosafety Cabinets Can Benefit a Laboratory

Biosafety cabinets are considered one of the most essential tools for biological and chemical laboratories, enabling research that was previously impossible. These cabinets serve to prevent contamination of both the research room and materials, with some types able to prevent cross-contamination between samples. The combined features of these devices create a completely sterile research environment for both employees and materials.

Directional airflow is created from the laboratory to the hood through strong fans located around the perimeter of the working chamber. This airflow captures any materials produced by the samples, making it necessary to maintain a sterile workplace. Contaminated air is filtered multiple times before being safely recirculated within the laboratory or released outside.

There are multiple types of Biological Safety Cabinet, categorized based on the following criteria:

  • filtration system;
  • air circulation;
  • size;
  • biosafety level.

Understanding these categories in greater detail can assist in selecting the appropriate Biological Safety Cabinet. Choosing the right equipment is crucial for both saving money and preserving precious working space.

Biological Safety Cabinets Class II: Description of the Types

Class II biosafety cabinets (BSCs) are widely utilized in laboratories across the globe for handling various types of pathogens. The main difference in comparison to Class I is that the airflow is not recirculated. Class II Biosafety Cabinets are available in five distinct types, which include:

  • A1 – This option is the most cost-effective as it filters air back into the room. It has an airflow speed of 75 ft/min.
  • A2 – This option provides cross-contamination-free spaces within the working chamber, making it safe to work with multiple samples at once. It has an airflow speed of 100 ft/min.
  • B1 – This option features two separate airflows for the main filtering system and outside air. It has an airflow speed of 100 ft/min.
  • B2 – Further details regarding this type will be provided below.
  • C1 – This Biosafety Cabinet can operate in multiple air filtering modes mentioned in other Class II type descriptions.

Biological Safety Cabinets Class II: Type B2

This type of biosafety cabinet can be utilized for handling hazardous materials up to biosafety level 3. It is also referred to as the Total Exhaust Cabinet, owing to its capacity to function without recirculating air within the system. This attribute is particularly crucial for laboratories that frequently handle dangerous substances. Experts regard it as the most secure Class II Biosafety Cabinet.

Class II Type B2 airflow systems are quite extensive and require a large facility for installation. All the airflow in both directions is exhausted after being filtered.

Class II BSCs feature sensors and alarm systems for added safety, which help to monitor exhaust airflow.

Biological Safety Cabinets Class III

Class III biosafety cabinets (or «Glove Boxes») are suitable for working with materials up to biosafety level 4, such as the well-known Ebola, Marburg, and other lethal tropical viruses. BSC Class III features:

  • Lower pressure than the external environment to prevent air contamination if the Biosafety Cabinet frame integrity is compromised.
  • No direct access to the sample (some BSCs include a glove integrity testing kit).
  • Samples enter the frame through double doors to preserve lower pressure and keep contaminated air inside.
  • Special system with double HEPA filtration.
  • Exhaust air is typically incinerated.

Furthermore, the majority of loading and disinfection tasks can be accomplished by a single employee.