What are the core principles governing the design of the separation between clean production areas and general storage or outer packaging areas in the daily chemical industry?
1. Principles of Pressure Differential and Unidirectional Airflow
Maintain positive pressure in the clean zone, with air pressure ranked as follows: Clean Zone > Buffer Room > Outer Packaging/General Storage Area. Natural backflow of external air into the clean zone is strictly prohibited.
Airflow direction must be fixed: Clean Zone → Buffer Room → Non-clean Outer Packaging/Storage; reverse airflow is absolutely forbidden.
Direct door connections between the two zones are not permitted; a buffer transition space must be installed. Direct openings risk introducing dust, microorganisms, insects, or outer packaging debris due to pressure fluctuations the moment a door is opened.
2. Principles of Unidirectional Material Flow and Separation of Clean/Dirty Streams
Material path: Outer packaging materials/raw materials → External cleaning room → Buffer → Clean zone;
Finished product path: Clean zone (primary packaged product) → Clean transfer/buffer → Outer packaging area;
Prohibited: Raw materials or packaging materials with outer cartons still attached entering the clean zone directly; clean semi-finished products flowing back to general storage or outer packaging areas.
Waste disposal: A dedicated waste exit for the clean zone must be established; it must not share the same passageway as the material entrance.
3. Principles of Strict Zoning and Segregation of Personnel Flow
Personnel cannot enter the clean zone directly from general storage or outer packaging areas.
Personnel flow path: General area → First changing room → Second changing room → Buffer → Clean zone;
Random movement across zones is prohibited; outer packaging operators must not enter the clean production zone at will. Any necessary passage requires completing the full gowning and disinfection process.
4. Principles of Physical Barriers
Use continuous, airtight enclosure structures for complete separation; division using only roller shutters, simple partitions, or wire mesh is prohibited. All wall gaps and penetrations for pipes or cables must be sealed to prevent the leakage of dust, insects, or air.
Doors and windows must be airtight; direct-access doors between zones should preferably be interlocked to prevent pressure differential loss caused by both doors opening simultaneously. 5. Principle of Zonal Control Based on Contamination Risk
General storage and outer packaging areas—characterized by significant levels of cardboard dust, ink particles, risks of pest infestation, and microbial contamination from external packaging materials—are designated as the "high-contamination side."
Clean zones are designated as the "low-contamination, controlled side." All isolation measures are designed to prevent the migration of contaminants from the high-contamination side into the clean zones.
Drainage systems, floor drains, and ventilation vents must not interconnect across zones; dust collection and exhaust systems for outer packaging areas must be independent, and exhaust air must not recirculate into clean zones.
6. Principle of Non-Overlapping Functional Zones
Spatial layout follows these guidelines: clean zones are grouped together, while outer packaging and general storage areas are grouped together, with buffer corridors serving as the sole transitional interface.
Locations such as delivery truck unloading bays and outer packaging workstations must not be situated immediately adjacent to fresh air intakes on the exterior walls of clean zones.
7. Principle of Regulatory Compliance
The “Good Manufacturing Practice for Cosmetics”explicitly requires that clean production workshops be effectively separated from areas such as storage and outer packaging to prevent cross-contamination. Isolation designs must meet on-site inspection standards, avoiding layout flaws such as direct connections between zones without an intervening buffer.