What is the difference between a biological safety cabinet and a hood?

The differences between a biological safety cabinet and a hood can be understood through their design, function, and areas of application.

Biological Safety Cabinet (BSC)

• Design and Function:

  • Biological safety cabinets are containment devices designed for handling biohazardous materials.
  • They provide protection to the operator, the environment, and usually also to the product or materials being handled.
  • Exhaust air is filtered through HEPA filters to prevent the release of contaminants.

• Types:

  • Class I: Provides personnel and environmental protection only, with air flow directed away from the researcher but not HEPA-filtered.
  • Class II: The most common type, it provides protection to personnel, product, and environment. It has both supply air and exhaust air HEPA filters.
  • Class III: Fully enclosed and hermetically sealed, with all procedures conducted through arm-length rubber gloves. Used in high-level containment labs.

Hoods

• Laminar Flow Hoods:

  • These are horizontal or vertical flow clean-air benches primarily used for product protection.
  • They are not suitable for work with biohazardous or chemical hazards, as they do not provide adequate protection to the operator or the environment.
  • Air flow is usually unidirectional and laminar, creating a clean work environment but without the containment capabilities of a biological safety cabinet.

• Chemical Fume Hoods:

  • These are ventilated enclosures designed to limit exposure to hazardous chemical fumes, vapors, dusts, and gases.
  • They are used to protect the worker by drawing air away from the work area and exhausting it out of the building.
  • Unlike biological safety cabinets, chemical fume hoods do not typically have HEPA filters on the exhaust system for containing biohazardous materials.

Summary of Differences

• Primary Purpose: Biological safety cabinets provide protection to personnel, environment, and product, while hoods (laminar flow or chemical fume) are primarily for product protection or chemical fume exhaustion.
• Containment Capabilities: Biological safety cabinets have HEPA filters and are designed for containment of biohazardous materials, while hoods generally do not.
• Application: Biological safety cabinets are used for handling infectious materials, while laminar flow hoods are used for cell cultures and other applications requiring a clean work environment, and chemical fume hoods are used for handling hazardous chemicals.

In conclusion, while both biological safety cabinets and hoods serve important roles in laboratory settings, their design, function, and areas of application differ significantly. Choosing the right equipment depends on the specific needs and hazards associated with the laboratory work being performed.