A desktop clean bench, also known simply as a clean bench or laminar flow bench, is a piece of equipment used in laboratories, medical facilities, and sometimes in industry. It provides a controlled environment where clean air is forced through a HEPA (High-Efficiency Particulate Air) filter, creating a laminar airflow across the work surface.

Clean benches are used to create a sterile or particulate-free workspace for tasks that require a clean environment but not necessarily sterile conditions. They protect samples, equipment, and products from contamination by providing a continuous flow of filtered air. They are often used in environments where the work needs to be protected from contaminants coming from above.

Applications: Clean benches are used in various fields such as microbiology, tissue culture, pharmaceutical manufacturing, electronics assembly (especially for sensitive components), and any situation requiring a clean and particle-free environment for working with materials. 

Limitations: It's important to note that clean benches do not provide sterile conditions like a biosafety cabinet (which has additional features such as a closed working area and inward airflow for protection of the operator and the environment). Therefore, they are suitable for work that requires a clean environment but not for work that involves hazardous materials or biological agents that require containment.

A desktop clean bench can be placed on the desktop of the laboratory, suitable for compact laboratory and other application scenarios.