The hood described in this document is a walk-in type with unidirectional airflow, designed for the handling of non-active powdered excipients. It is GMP-compliant and designed to ensure containment of powders within a confined area, while protecting the operator from contact and inhalation.

The vertical unidirectional airflow (UDAF) guarantees:

Microbiological Grade C (per GMP Volume 4 – Annex 1) and ISO 8 particle classification (ISO 14644-1) during operation.

Microbiological Grade A (per GMP Volume 4 – Annex 1) and ISO 5 particle classification (ISO 14644-1) at rest.

The air handling system is designed for partial recirculation, generating inward airflow from the room into the hood, creating dynamic negative pressure within the hood’s confinement area. Air is drawn from the work area by a fan and passed through H14 HEPA filters located at the top of the hood. Air is collected through louvered intake grilles at the bottom, filtered, and recirculated through absolute filters. Exhaust air is released back into the room through ceiling-integrated H14 HEPA filters.

 

Filtration stages before reintroduction:

H14 HEPA filter

G4 filters are housed within the intake grilles

F9 filters are installed in safety canisters with BIBO (Bag-In Bag-Out) filter change system

 

The fan is inverter-controlled, managed by a differential pressure transmitter monitoring pressure drop across HEPA filters. Filter clogging is monitored via differential pressure transmitters connected to the PLC system, with integrated alarms. A PLC-based control system and a touchscreen HMI are included. LED lighting is integrated in the top section of the hood.