A large amount of dust is generated when weighing raw materials, excipients, and API powders in pharmaceutical manufacturing. Negative pressure uses air pressure difference to lock the dust in the weighing chamber and prevent it from leaking out. It also takes into account the three major requirements of drug quality, personnel safety, and GMP compliance, which is completely opposite to the function of ordinary positive pressure laminar flow hoods.

In clean environments such as pharmaceuticals, biological laboratories, precision electronics, and medical disinfection, cleanroom environmental control is the core of quality and safety. Material transfer is the main cause of cross-contamination in clean areas, and pass-through windows, as specialized purification equipment, are used for the transfer of small materials between areas of different cleanliness levels and between clean and non-clean areas. They can effectively reduce the frequency of cleanroom door openings, block airflow and contaminant intrusion, and are an indispensable core facility in the cleanroom system.