5 Key Clean Room Testing Criteria Every Semiconductor & Pharmaceutical Project Must Know

In the semiconductor and pharmaceutical industries, every detail can determine a product's success or failure. Chip manufacturing is extremely sensitive to micron-sized particles, while pharmaceutical manufacturing processes have strict regulatory requirements for microbial control. Whether ISO certification or GMP audits, scientific and systematic clean room testing is essential.

This article will introduce five essential clean room testing standards to help companies understand the core content of clean room standards and meet clean room requirements in actual production.

Why do the semiconductor and pharmaceutical industries place higher demands on Clean Room Testing?

In a semiconductor industry, one particle in the air, which we cannot see with the naked eye, can scrap the whole wafer. In pharmaceutical manufacturing, exposure to microbial contamination occurs due to an inadequate clean room control and is a direct cause of hazards to drug safety and patient health.

These two industries depend largely on clean room testing as compared to other sectors. They not only have to satisfy the international standards of clean rooms, but they must also be able to combine the specific process features with the process in order to keep processes stable and within compliance levels across the whole processing.

Five Key Clean Room Testing Standards to Focus on

Air Particle and Microbial Testing

This is one of the major elements of measuring Clean Room Classification. The particle size distribution and the microbial count of the air are measured by the use of particle counters and microbial sedimentation cultures, respectively.

• Semiconductor Industry: ISO Class 4-5 is typically required.

• Pharmaceutical Industry: Based on GMP standards, continuous monitoring is required in different classification areas.

Meeting this Clean Room Requirement means that potential sources of contamination in the environment are effectively isolated.

Airflow Organization and Air Change Frequency

How air flows determines whether particles and microorganisms can be removed promptly.

• Chip Manufacturing: Vertical unidirectional airflow is often used, with air changes up to hundreds of times per hour.

• Pharmaceutical Industry: Non-unidirectional or mixed airflow is often used, with 20-40 air changes per hour.

Clean Room Testing ensures that the workshop environment meets the Clean Room Standards set during the design phase by measuring airflow velocity and air change frequency.

Pressure Differential and Compartmental Isolation

A reasonable pressure differential must be maintained between different functional areas to prevent backflow of contaminated air.

Common pressure differentials in the pharmaceutical industry are 10–15 Pa.

Semiconductor production areas require even higher pressure differentials to prevent particle backflow.

Clean room testing at this stage is crucial for passing regulatory reviews and preventing cross-contamination, and is a clean room requirement that companies must consistently monitor.

Temperature and Humidity Stability

Temperature and humidity not only affect employee comfort but also directly impact process and product quality:

• Semiconductors: Low humidity can easily generate static electricity, while high humidity can affect the photolithography process.

• Pharmaceuticals: Excessive humidity can cause drug degradation or microbial growth.

Clean room standards clearly define temperature and humidity, and testing must confirm that the actual environment can maintain long-term stability within these limits.

Key Equipment and Filtration System Performance

The stable operation of a clean room depends on equipment such as Fan Filter Units (FFUs), Air Handling Units (AHUs), and HEPA/ULPA filters.

Clean room testing includes:

• Testing filter efficiency

• Checking for uniform air volume and velocity

• Verifying the reliable operation of air showers and pass-through windows

Only when equipment meets these standards can the entire system truly meet stringent clean room standards.

How can we truly implement test results?

Many companies pass inspections during final acceptance, but gradually deviate from standards during subsequent operation. To ensure long-term compliance, the following measures are necessary:

• Regular re-inspections: Conduct complete clean room testing every 6-12 months.

• Continuous monitoring: Install real-time monitoring equipment to ensure data traceability.

• Standardized personnel training: Avoid manual operations that pose the greatest risk of contamination.

These measures are not only an extension of clean room requirements but also core means of ensuring product compliance and safety.

Conclusion

Independent of whether you are a semiconductor company or working in the pharmaceutical industry, only through a comprehensive knowledge and application of each of the following five clean room testing benchmarks can you possibly comply with the most rigorous clean room standards and requirements.

Having an accumulation of more than 17 years of industry experience, we do more than testing services. We customize a complete solution, including design, construction, operations and maintenance, that helps companies to obtain certification and establish safe production.

If you're planning a new project, contact us to learn more about our professional, one-stop clean room services.