The core requirements for vertical flow workbenches in the biomedical field revolve around three key areas: sterility assurance, biosafety, and compliance. It is necessary to prevent sample contamination and also avoid the leakage of harmful microorganisms that could endanger operators.
These requirements precisely match the high-risk characteristics of biomedical scenarios (such as cell culture and microbial testing), and can be specifically classified into the following five categories:

1. Ultimate cleanliness and air flow control
This is the foundation for ensuring that the samples are not contaminated by miscellaneous bacteria, and the requirements are far higher than those in ordinary industrial scenarios.
Cleanliness grade: It must reach ISO level 5 (Class 100), that is, the number of particles ≥0.5μm per cubic meter of air is ≤ 3,520, and there are no live microorganisms (sedimentation bacteria and airborne bacteria tests are required).
Airflow stability: The vertical airflow velocity should be controlled within the range of 0.36-0.54m/s, and the airflow uniformity should be no less than 80% to prevent local airflow disorder from causing pollution diffusion.
Airflow isolation: An “air curtain barrier” needs to be formed to prevent external non-clean air from invading from the edge of the workbench. In some scenarios, negative pressure design is also required (such as when dealing with pathogenic microorganisms).
2. Strict biosafety protection
For operations that may generate harmful microorganisms (such as pathogenic bacteria and viruses), two-way protection of “human-sample – environment” is required.
High-efficiency filtration system: The air outlet must be equipped with a HEPA high-efficiency air filter (filtration efficiency ≥99.97%@0.3μm). In some high-risk scenarios (such as BSL-3 laboratories), ULPA ultra-high-efficiency filters need to be upgraded to prevent microorganisms from being discharged with the airflow.
Leak-proof design: The connection points between the workbench shell, the filter and the frame must be sealed tightly, with a leakage rate of no more than 0.01%. The operation door should be sealed with soft rubber strips and be seamless when closed.
Negative pressure is optional: When handling highly pathogenic microorganisms, a relative negative pressure (-5Pa to -15Pa) should be maintained inside the workbench to prevent internal contaminated air from leaking into the external environment.
3. Corrosion-resistant and easy-to-clean material
Disinfectants (such as 75% ethanol and chlorine-containing disinfectants) are frequently used in biomedical operations. The materials used must be resistant to chemical corrosion and have no cleaning dead corners.
Main material: The shell and workbench surface should be made of 304 or 316L stainless steel, with a smooth surface free of pores, not rusting, not adsorbing microorganisms, and capable of withstanding high-temperature sterilization at 121℃ (required in some scenarios).
Countertop design: The countertop should be integrally formed without any seams. The edge should have a water-blocking edge (with a height of ≥5mm) to prevent liquid overflow, and the liquid can be quickly discharged through the drainage hole (equipped on some models).
No dead corner structure: The internal fillet radius is ≥5mm to prevent dust accumulation or residual liquid at right angles. Lamps, switches and other components should be installed recessed and not protrude from the inner wall to reduce cleaning blind spots.
4. Functional design adapted to experimental requirements
It is necessary to be in line with the actual scenarios of biomedical operations to enhance convenience and safety.
Ultraviolet disinfection function: Equipped with a 254nm wavelength UV-C ultraviolet lamp, the irradiation dose should be ≥ 10,000 μW · s/cm². It can sterilize the interior of the workbench before and after operation (it needs to be equipped with a delayed start and personnel departure sensor to prevent ultraviolet rays from injuring people).
Lighting and Observation: The illuminance on the workbench surface should be ≥600lux, and there should be no glare or shadows to ensure that the operator can clearly observe the state of cells or microorganisms.
Anti-static optional: Some cell experiments (such as suspension cell operations) require the workbench surface to have an anti-static function (surface resistance 10⁶-10¹¹Ω) to prevent static electricity from damaging cells or adsorbing particles.