What is the difference between ISO 4 and ISO 5 cleanroom?

What is the Difference Between ISO 4 and ISO 5 Cleanroom?

Cleanrooms are specialized environments that control contamination by particulate matter, temperature, humidity, and pressure. They are categorized according to the International Organization for Standardization (ISO) classification system, where each class has specific limits for allowable contamination levels. ISO 4 and ISO 5 are two such classifications, each with distinct characteristics and requirements.

1. Particle Count Standards

The primary difference between ISO 4 and ISO 5 cleanrooms lies in their particle count standards. An ISO 4 cleanroom has stricter limits, allowing no more than 10 particles per cubic meter for particles of 0.1 micrometers (µm) and no more than 2 particles per cubic meter for particles of 0.2 µm. In contrast, an ISO 5 Cleanroom permits up to 3,520 particles per cubic meter for 0.5 µm and 29 particles per cubic meter for 1.0 µm. 

2. Applications

ISO 4 cleanrooms are generally used in applications that demand the highest level of cleanliness, such as Semiconductor manufacturing, aerospace components, and certain pharmaceutical processes. They are critical in environments where even the slightest contamination can lead to product failure or compromised research results. ISO 5 Cleanrooms, while still maintaining a high cleanliness level, are often utilized in biotechnology, medical device manufacturing, and some pharmaceutical operations where the risk of contamination is lower than in ISO 4 scenarios.

3. Airflow and Filtration

The design and airflow rates in ISO 4 cleanrooms are also more stringent. ISO 4 environments often require a higher rate of air exchanges per hour, which can exceed 600 air changes per hour. This ensures that contaminants are continuously removed from the environment. ISO 5 cleanrooms typically require fewer air changes, around 240 to 480, depending on the specific application. The use of high-efficiency particulate air (HEPA) or ultra-low penetration air (ULPA) filters is essential in both classifications, but ISO 4 cleanrooms may use more advanced filtration systems to meet their rigorous standards.

What are the Requirements for ISO 4 Cleanroom?

ISO 4 cleanrooms must adhere to strict requirements in order to maintain their classification. The key requirements include a maximum allowable particle count, where the cleanroom must not exceed 10 particles per cubic meter for 0.1 µm and 2 particles for 0.2 µm. Additionally, the cleanroom must maintain a controlled temperature, typically between 20-24°C, and humidity levels ideally below 30% to reduce the risk of electrostatic discharge and other contamination sources. 

What are the Limits for ISO5?

Particle Count

• Maximum of 3,520 particles per cubic meter for 0.5 µm.

• Maximum of 29 particles per cubic meter for 1.0 µm.

• Maximum of 8 particles per cubic meter for 5.0 µm.

Air Quality

• The cleanroom must be equipped with HEPA or ULPA filters to ensure efficient air purification.

• Required airflow rates typically range from 240 to 480 air changes per hour.

Temperature and Humidity Control

• Temperature should be maintained within the range of 20-24°C.

• Humidity levels must be kept ideally between 30% and 60%.

Pressure Differentials

ISO5 cleanrooms should maintain a positive pressure relative to surrounding areas to prevent contamination from adjacent spaces.

Monitoring and Maintenance

• Regular monitoring of particle counts and environmental conditions is essential for compliance.

• Routine maintenance of filtration systems and cleanroom surfaces to minimize contamination risks.

Personnel Protocols

• Strict gowning and decontamination protocols must be followed by all personnel entering the cleanroom.

• Training for personnel on cleanroom protocols is mandatory to ensure compliance and maintain cleanliness standards.

What Temperature Should A Clean Room Be?

Importance of Temperature

Maintaining a temperature of 20 to 24 degrees Celsius (68 to 75 degrees Fahrenheit) is essential in cleanrooms for product integrity and personnel comfort, preventing thermal fluctuations that could disrupt sensitive processes across industries like pharmaceuticals and semiconductors.

Personnel Comfort and Safety

Temperature control is critical for staff comfort and safety. Extreme temperatures can lead to discomfort, increasing the risk of errors. A stable environment helps maintain focus, reducing the likelihood of contamination and ensuring efficient operations.

Continuous Monitoring

Continuous temperature monitoring is necessary for compliance with cleanroom standards. Real-time data from sensors allows for quick adjustments to HVAC systems, ensuring stability. Maintaining consistent temperatures also aids in humidity control, crucial for preventing electrostatic discharge and protecting sensitive materials.

What is the Ventilation Rate for a Clean Room?

1. Air Change Rate: The ventilation rate in A CleanRoom is typically expressed as the number of air changes per hour (ACH). For ISO5 cleanrooms, the recommended air change rate ranges from 240 to 480 ACH. In ISO Class 4 environments, this can exceed 600 ACH to maintain the stricter cleanliness requirements.

2. Design Considerations: Cleanroom design must account for effective airflow patterns to minimize the risk of contamination. Laminar flow systems are often utilized, where air is filtered and directed in a uniform manner across the work area, ensuring that contaminants are effectively removed from the breathing zone of personnel and the surfaces of equipment.

3. Filter Types: High-efficiency particulate air (HEPA) filters are standard in cleanrooms, capable of trapping 99.97% of particles down to 0.3 µm. In higher-grade environments, ultra-low penetration air (ULPA) filters may be used to capture even smaller particles. Regular maintenance and replacement of these filters are crucial to sustain the desired ventilation rate and cleanliness levels.

4. Monitoring and Control: Continuous monitoring of airflow and pressure differentials within the cleanroom is essential. Automated systems can adjust fan speeds and ventilation rates in response to real-time data, maintaining optimal conditions and preventing contamination events.

5. Positive Pressure Maintenance: Cleanrooms should maintain positive pressure relative to surrounding areas to prevent the ingress of unfiltered air. This positive pressure is typically achieved through careful control of the ventilation system, ensuring that the airflow from the cleanroom to adjacent areas is directed outward.

What is Not Allowed in a Clean Room?

Food and Drinks

Consumption of food and beverages is strictly forbidden in cleanrooms. The introduction of organic materials can significantly increase the risk of contamination, potentially compromising sensitive processes or products.

Personal Items

Items such as bags, coats, and personal Electronics are typically not allowed unless specifically designed for cleanroom use. These items can carry dust, dirt, and other particulates that may contaminate the cleanroom environment.

Cosmetics and Fragrances

The use of cosmetics, perfumes, and scented personal care products is prohibited. These substances can emit volatile organic compounds (VOCs) and other contaminants that could disrupt the cleanroom's controlled environment.

Unapproved Equipment

Only equipment that has been specifically approved for cleanroom use is permitted. Tools and devices must be designed to minimize particle generation and be easily cleanable to maintain the cleanliness of the environment.

Unmonitored Entry and Exit

Access to the cleanroom must be controlled and monitored to prevent unauthorized entry. Personnel must follow strict gowning and decontamination protocols before entering to minimize the risk of contamination.

What is an ISO 6 Cleanroom?

An ISO 6 cleanroom is a controlled environment that meets specific cleanliness standards as defined by the International Organization for Standardization. It allows a maximum of 1,000 particles per cubic meter for particles of 0.5 micrometers (µm) and 29 particles per cubic meter for 1.0 µm. ISO 6 Cleanrooms are commonly used in industries where the risk of contamination is moderate, such as certain pharmaceutical applications, electronics manufacturing, and research laboratories.