CLEANROOM modular cleanroom grades conventional cleanroom

---

The highest level of cleanliness, where the product is directly exposed during aseptic operations.

Examples:

• Aseptic filling of vials and syringes
   
• Ampoule sealing
   
• Sterile connections
   
• Open sterile equipment handling
   

Requirements:

• Unidirectional airflow (laminar flow) with HEPA filters
   
• Air velocity: ~0.36–0.54 m/s to sweep away particles
   
• Pressure differentials to protect from less clean areas
   

Particulate Limits (per m³):

• At rest: 3,520 particles ≥0.5µm; 0 particles ≥5µm
   
• In operation: 3,520 particles ≥0.5µm; 0 particles ≥5µm
   

Simple Term: 👉 The “surgical zone” of pharmaceutical manufacturing.

The supporting clean area surrounding Grade A zones.

Examples:

• Background for filling machines
   
• Personnel gowning area before entering Grade A
   

Requirements:

• Works in tandem with Grade A
   
• HEPA-filtered air supply
   
• Maintained pressure differential vs. Grade C/D
   

Particulate Limits (per m³):

• At rest: 3,520 particles ≥0.5µm; 29 particles ≥5µm
   
• In operation: 352,000 particles ≥0.5µm; 2,900 particles ≥5µm
   

Simple Term: 👉 The “buffer zone” around aseptic filling.

Used for less critical stages of sterile product manufacturing.

Examples:

• Preparation of solutions before sterile filtration
   
• Staging of equipment and materials
   

Requirements:

• HEPA-filtered air
   
• Not aseptic-critical, but controlled environment
   

Particulate Limits (per m³):

• At rest: 352,000 particles ≥0.5µm; 2,900 particles ≥5µm
   
• In operation: 3,520,000 particles ≥0.5µm; 29,000 particles ≥5µm
   

Simple Term: 👉 The “preparation area” before entry into aseptic zones.

The lowest cleanroom grade, used for non-critical stages.

Examples:

• Raw material preparation
   
• Bulk powder weighing (before sterilization)
   
• Washing/cleaning of equipment (before sterilization)
   

Requirements:

• General clean air supply (not as strict as A–C)
   

Particulate Limits (per m³):

• At rest: 3,520,000 particles ≥0.5µm; 29,000 particles ≥5µm
   
• In operation: Not defined (depends on process risk assessment)
   

Simple Term: 👉 A “controlled but not sterile” support area.
 

• Conventional Cleanroom → Entire room is controlled with HVAC + HEPA.
   
• Laminar Airflow (LAF) Cleanroom → Controlled airflow in a single direction (used in Grade A).
   
• Modular Cleanroom → Flexible, pre-fabricated panels for fast setup & expansion.
   
• Hard wall Cleanroom → Permanent, rigid wall panels (common in pharma).
   
• Soft wall Cleanroom → Flexible curtain walls, used for temporary or less critical operations.
   
• Isolators / RABS → Closed barrier systems providing Grade A protection with minimal human intervention.
   

Air & Environmental Control:

• AHUs (Air Handling Units) – maintain temperature, humidity, pressure differentials.
   
• HEPA / ULPA Filters – for particle control.
   
• LAF Units (Laminar Airflow workbenches) – aseptic manipulations.
   
• Pass Boxes / Pass-Through Chambers – for material transfer.
   
• Airlocks (Personnel & Material) – contamination control.
   

Processing Equipment:

• Fractionation tanks – for plasma separation.
   
• Chromatography systems – for protein purification.
   
• Filtration units (sterile / ultrafiltration) – virus removal, purification.
   
• Aseptic filling & stoppering machines – vials, ampoules, syringes.
   
• Lyophilizes (Freeze-dryers) – for plasma proteins & injectables.
   

Utility & Support Systems:

• WFI (Water for Injection) Systems – critical clean utility.
   
• CIP/SIP Systems (Clean/Steam-in-place) – automated cleaning & sterilization.
   
• Compressed Air, Nitrogen, CO₂ Systems – process gases.
   
• Cold Rooms & Freezers – plasma storage.
   

Monitoring & Safety:

• Particle counters – for environmental monitoring.
   
• Bio-decontamination units (H₂O₂ fumigation) – sterilization.
   
• Differential pressure gauges – air pressure monitoring between zones.
   

• Personnel Flow: Gowning sequence → Grade D → Grade C → Grade B → Grade A.
   
• Material Flow: Raw → staged in Grade D/C → sterilized transfer → final aseptic use in Grade A.
   
• Barriers: Airlocks, pass boxes, pressure cascades.