Analysis of Cleanroom Production Environment and HVAC Purification System for Cosmetics

With the full implementation of the Cosmetics Production Quality Management Regulation, a clean production environment has become a critical factor in ensuring the safety and quality of cosmetic products. In particular, leave‑on cosmetics applied to the eye area, children’s skin, and lip surfaces must strictly comply with cleanroom management standards during semi‑finished product storage, filling, packaging, and equipment cleaning.

What Is an HVAC Purification System?

An HVAC purification system continuously supplies air that has been treated for temperature, humidity, and cleanliness to maintain stable environmental parameters inside a cleanroom – including temperature, humidity, airflow velocity, pressure difference, and airborne particle concentration. This system effectively eliminates heat, moisture, and dust contamination during production.

Components of an HVAC Purification System

A complete air purification system typically consists of the following three parts:

• Air handling equipment – responsible for heating, cooling, humidifying, dehumidifying, and primary, medium, and high‑efficiency filtration.
• Air delivery and circulation equipment – including fans, ducts, valves, supply air diffusers, and return air grilles.
• Cooling/heating source and energy management system – providing refrigeration, heating, and system operation control.

Three‑Stage Filtration: Functions and Roles

HVAC purification systems generally adopt a three‑stage filtration structure, with each stage having a clearly defined function:

• Primary (pre‑filter) – captures suspended particles ≥3 μm; used primarily for fresh air pre‑filtration to protect downstream equipment.
• Medium filter – removes particles ≥0.3 μm; serves as pre‑protection for the HEPA filter.
• HEPA/ULPA filter – made of ultra‑fine glass fiber paper; capable of filtering particles ≥0.1 μm; installed at terminal supply air diffusers in the cleanroom.

Filter Replacement and Leak Detection Recommendations

• Primary and medium filters are recommended to be replaced annually. In environments with high dust loads, the replacement cycle may be shortened.
• HEPA filters should be leak‑tested at least once a year. A mobile scanning method is recommended for detecting leak points. Any leaks found should be repaired or the filter replaced promptly.

Core Environmental Requirements for Cleanrooms

• Clean‑zone air must meet the required cleanliness level for airborne particles and microorganisms.
• Windows, pipe penetrations, and equipment connections must be tightly sealed to prevent ingress of external contaminants.
• Effective physical barriers and pressure differential gradients must be maintained between areas of different cleanliness classes to avoid cross‑contamination.
• The environment must be disinfected regularly using non‑residue disinfectants, and the disinfection process must be fully documented.

Key Differences Between Purification HVAC and Standard Comfort HVAC

Compared with standard comfort air conditioning, a purification HVAC system differs significantly in several aspects:

• Air filtration level – Standard comfort AC typically uses only 1–2 stages of coarse filtration, while purification HVAC uses 3–4 stages of deep filtration.
• Airflow control – Purification HVAC emphasises laminar or unidirectional airflow to minimise particle dispersion; standard AC generally uses turbulent or mixed flow.
• Pressure difference control – Cleanrooms have strict pressure difference requirements relative to outdoors and adjacent rooms; standard AC has no such requirements.
• Air changes per hour and energy consumption – Purification HVAC typically achieves 15–30 ACH (air changes per hour) or more, far higher than standard AC (about 5–10 ACH), resulting in higher energy consumption.

Recommended Monitoring Items and Frequencies

To ensure continuous and stable operation of the purification system, the following monitoring frequencies are recommended:

• Temperature, humidity, pressure difference – tested twice daily.
• HVAC operating status – inspected once every two hours.
• Air velocity and air volume – tested once per month.
• Airborne particles, floating bacteria, settling bacteria – tested once per quarter or semi‑annually.
• Ozone concentration – monitored weekly during disinfection, with a full test once per quarter.

Building and maintaining a cleanroom environment for cosmetics production relies on a properly designed HVAC purification system and disciplined operational management. Manufacturers should select appropriate filtration levels and strictly follow monitoring schedules based on product characteristics and regulatory requirements, ensuring the safety and quality of every batch. For more detailed guidance on cleanroom design or validation, please stay tuned for our future content.