Clean Benches

What is a clean bench?

Clean bench also known as a laminar flow hood or clean air workstation, is an enclosed workspace designed to maintain a high level of cleanliness by providing a continuous flow of HEPA (High-Efficiency Particulate Air) filtered air over the work surface. It is a critical piece of equipment used in scientific research, medical and pharmaceutical industries, semiconductor manufacturing, and other environments where maintaining an ISO Class 5 (previously known as Class 100) or cleaner environment is essential.

The main functions of a clean bench include:

1. Air Filtration: The primary function is to filter out airborne particulates from the ambient environment. A fan draws in room air and pushes it through a HEPA filter before releasing it across the work surface in a unidirectional (laminar) airflow pattern. This ensures that contaminants are not allowed to settle on sensitive materials being handled within the bench.

2. Particle Control: The constant flow of filtered air prevents the accumulation of dust, microorganisms, or other particles that could contaminate samples, sterile products, or delicate assemblies.

3. Process Protection: Unlike fume hoods which protect personnel from hazardous substances, clean benches primarily protect the process from contamination by the operator and the surrounding environment. They are not designed for containing toxic fumes or volatile chemicals; such operations require a chemical fume hood instead.

4. Sterile Work Environment: Clean benches are often used when working with biological cultures, tissue culture preparations, or assembling medical devices that require a sterile environment to minimize the risk of contamination.

5. Quality Control: In many manufacturing processes, particularly those involving electronics or optics, clean benches ensure that parts are assembled under highly controlled conditions to prevent defects caused by particulate contamination.

In essence, a clean bench creates a mini-environment with a much higher degree of cleanliness than the surrounding room, ensuring that sensitive processes remain uncontaminated. However, it's important to note that clean benches do not provide protection for the user against harmful vapors or aerosols; appropriate personal protective equipment must still be worn, and proper handling procedures followed.