What is ISO Class 5 equivalent to?

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What is ISO Class 5 equivalent to

A cleanroom is a controlled environment with low levels of pollutants such as dust, airborne microbes, aerosol particles, and chemical vapors. Cleanrooms are used in industries like pharmaceuticals, biotechnology, medical devices, microelectronics, aerospace and others where cleanliness and/or environmental control are critical requirements.

Cleanroom standards provide specifications for desired air purity levels, temperature, humidity, airflow patterns, pressure differentials, gowning requirements and material restrictions in cleanrooms. These standards allow cleanrooms to be constructed, validated and operated properly for their intended applications.

The most widely used international cleanroom classification standard is ISO 14644 published by the International Organization for Standardization (ISO). It consists of multiple parts that cover topics ranging from cleanroom classifications, metrology, testing methods, contamination control and design requirements among others https://www.iso.org/standard/53394.html.

ISO 14644 provides a standardized method to specify, measure and verify cleanroom environments based on the concentration of airborne particles. Compliance ensures the cleanroom meets the necessary cleanliness levels for its intended processes and products.

ISO 14644 Overview

The ISO 14644 set of standards were first developed to provide a unified global standard for cleanroom classifications and operation. The standards evolved from earlier national standards such as the US Federal Standard 209E for Airborne Particulate Cleanliness Classes in Cleanrooms and Clean Zones.

The original ISO 14644-1 standard was published in 1999, providing classifications for air cleanliness in cleanrooms and associated controlled environments. This standard allowed for a globally recognized and consistent set of cleanroom classifications. ISO 14644-1 also provided test methods for determining concentrations of airborne particles in cleanrooms.

Since then, the ISO 14644 family of standards has expanded to provide additional guidance on cleanroom operations and monitoring. Some key standards include:

  • ISO 14644-2: Specifications for monitoring air cleanliness
  • ISO 14644-3: Test methods for metrology and measurement techniques
  • ISO 14644-4: Design, construction, and start-up of cleanrooms
  • ISO 14644-5: Cleanroom operations
  • ISO 14644-7: Cleaning of cleanrooms
  • ISO 14644-8: Classification of air cleanliness by chemical concentration

The ISO 14644 standards are continually revised and updated by subcommittee SC3 of the ISO Technical Committee 209 to reflect latest cleanroom technologies and industry practices.

Cleanroom Classifications

The ISO 14644-1 standard defines cleanroom classifications based on the concentration of airborne particles present. The cleanroom classes range from ISO Class 1 to ISO Class 9, with ISO Class 1 representing the cleanest environment with the lowest concentration of particles.

The particle concentration limits for each ISO class are defined in terms of the maximum number of particles of 0.1 μm and larger per cubic meter of air. For example, for ISO Class 5, the maximum concentration is 3,520 particles/m3 for particles ≥0.1 μm, and 20 particles/m3 for particles ≥0.5 μm. The higher the ISO class number, the higher the maximum allowable concentration of particles, and the lower the cleanliness. Classes 1 through 3 have additional stringent requirements for particle sizes smaller than 0.1 μm as well.

Here are the specifications for the cleanroom ISO classifications from ISO 14644-1 (ISO 14644-1:2015):

  • ISO Class 1: Max concentration of 10 particles/m3 for ≥0.1 μm particles, 1 particle/m3 for ≥0.2 μm particles
  • ISO Class 2: Max 100 particles/m3 for ≥0.1 μm particles, 10 particles/m3 for ≥0.2 μm particles
  • ISO Class 3: Max 1,000 particles/m3 for ≥0.1 μm particles, 100 particles/m3 for ≥0.2 μm particles
  • ISO Class 4: Max 10,000 particles/m3 for ≥0.1 μm particles, 1,000 particles/m3 for ≥0.2 μm particles
  • ISO Class 5: Max 100,000 particles/m3 for ≥0.1 μm particles, 20,000 particles/m3 for ≥0.2 μm particles
  • ISO Class 6: Max 1,000,000 particles/m3 for ≥0.1 μm particles
  • ISO Class 7: Max 352,000 particles/m3 for ≥0.5 μm particles
  • ISO Class 8: Max 3,520,000 particles/m3 for ≥0.5 μm particles
  • ISO Class 9: Max 35,200,000 particles/m3 for ≥0.5 μm particles

ISO Class 5 Standards

ISO Class 5 cleanrooms have strict requirements for particulate limits, air filtration, airflow, temperature/humidity controls, and personnel controls as per ISO 14644-1 standards. The maximum concentration limits are listed below:

  • 0.5 μm particles: 3,520 particles/m3
  • 5.0 μm particles: 29 particles/m3

To achieve these low particulate levels, ISO Class 5 cleanrooms require HEPA filters with 99.997% minimum efficiency on 0.3 μm particles. Air changes are typically 400-600 per hour. Temperature is maintained at 22°C ± 3°C while relative humidity stays within 45% and 55%.

Personnel entering an ISO Class 5 cleanroom must wear full protective garments including hoods, face masks, gloves, boots, and coveralls. All items and equipment brought inside are thoroughly cleaned and disinfected. Strict protocols minimize the introduction of contaminants from people.

For specific details, refer to the ISO 14644-1 standard published by the International Organization for Standardization (https://www.iso.org/standard/53394.html).

Achieving ISO Class 5

Achieving an ISO Class 5 cleanroom environment requires careful planning and execution. The room must be designed to limit particle generation and maximize airflow control. Common design elements include:

Staff must follow strict gowning procedures and cleaning protocols to limit particle introduction. Surfaces are wiped down frequently with DI water or IPA. Tools and equipment are cleaned and sterilized before entering the cleanroom. Monitoring particulate counts is critical to ensure the room stays within ISO 5 limits.

Applications of ISO Class 5

ISO Class 5 cleanrooms are used in industries that require an extremely high level of cleanliness and control over environmental particulate. Some key applications include:

Pharmaceutical Manufacturing – Sterile pharmaceuticals like injectable drugs or ophthalmic solutions are manufactured in ISO Class 5 cleanrooms. This prevents microbial contamination and particles from entering the drugs.

Medical Device Production – Medical devices like stents, knee/hip implants, surgical tools, and bandages are made in ISO 5 environments. This protects the devices from contamination during production.

Semiconductor Fabrication – Microchip production involves nanoscale structures where even tiny particles can ruin devices. ISO Class 5 cleanrooms provide the ultraclean environment needed.

Aerospace Manufacturing – Sensitive aerospace systems and space instruments are assembled in Class 5 cleanrooms. This prevents particles or chemicals from contaminating precision components.

Maintaining ISO Class 5

Maintaining an ISO Class 5 cleanroom requires continuous monitoring and strict protocols to control contamination. Here are some key aspects for maintaining ISO Class 5 standards:

Continuous monitoring – ISO Class 5 cleanrooms require constant monitoring of particle counts to ensure they remain below 3,520 particles per cubic meter for particles 0.5 microns and larger. This is typically done using an automated particle counter that continuously samples the air. Alerts are set to notify if counts rise above specified limits.

Training – All personnel working in an ISO Class 5 cleanroom must undergo extensive gowning training to learn proper hygiene, gowning, and behavior protocols to minimize contamination. Refresher training is usually annual.

Gowning procedures – Strict gowning procedures must be followed every time anyone enters an ISO Class 5 cleanroom. This includes wearing a hood, mask, goggles, suit, gloves, and boots. A step-by-step sequence must be followed to gown and de-gown to avoid contamination.

Cleaning – ISO Class 5 cleanrooms require frequent specialized cleaning. Surfaces are wiped with 70% IPA/DI water to remove residues. Floors are mopped. Tools and equipment are cleaned after each use. Only special cleanroom-approved supplies can be used.

Proper gowning, training, cleaning and continuous particle monitoring are all critical for successfully maintaining an ISO Class 5 cleanroom environment.

Transition Zones

Transition zones are areas between cleanrooms of different ISO classifications that help maintain proper pressurization between zones and preserve the integrity of each cleanroom environment. They act as buffers to prevent contamination from higher classified spaces entering cleaner spaces.

The purpose of transition zones is to allow personnel and equipment to transfer between different cleanliness zones without compromising the air quality. Proper gowning procedures must be followed before entering progressively cleaner spaces. Airlocks, gowning rooms, and air showers are common examples of transition zones.

Design considerations for transition zones include:1

  • Maintaining a pressure cascade from lower to higher classified spaces to direct airflow from clean to dirty areas
  • Using overlapping approach lobbies on entry and exit sides to maintain pressure cascades
  • Providing sufficient space for proper gowning procedures based on ISO classification
  • Incorporating airlocks and interlocking doors for access control
  • Installing tacky mats to control dust and dirt

Proper design, protocols, monitoring, and maintenance are critical for transition zones to effectively prevent contamination between cleanroom environments.

Non-Viable Particle Monitoring

Non-viable particle monitoring is a critical aspect of maintaining ISO Class 5 cleanroom standards. Particle counters use light scattering techniques to detect and count particles down to 0.1 μm in size. Monitoring is typically conducted at the following locations:

  • At the room entry points
  • In the center of the room
  • At equipment level in the work zones
  • Near the room exhaust

Counts are taken at designated intervals, such as hourly, daily or weekly. The data is recorded and analyzed to identify any adverse trends. Action levels are set to trigger increased monitoring or corrective actions if counts rise above set limits. Data management software creates reports that provide auditable records of particle counts over time.

According to Lighthouse, traditional particle counters are limited to detecting nonviable particles only. Viable monitoring requires specialized microbiological air sampling equipment and procedures.

Conclusion

ISO Class 5 cleanrooms have become incredibly important for ensuring contamination-free environments in a variety of industries and applications. Maintaining the stringent requirements for air purity, viable and non-viable particle counts, air changes, temperature and humidity is critical for success.

As technology advances, the future trends point towards more automation, modularity, energy efficiency and ease of installation for cleanroom equipment and infrastructure, while still meeting the tight ISO standards. New panel materials like sandwich panels are gaining popularity as well (Global Clean Room Panels Market Size, Share, Trends & Industry Analysis, 2022-2030). Staying up-to-date on the latest developments will ensure cleanrooms continue to enable contamination-free environments for critical processes across industries.

Proper cleanroom classification and adherence to ISO standards is crucial. With diligent monitoring, maintenance and adoption of advancing technologies, ISO Class 5 cleanrooms will continue to play a vital role in research, healthcare, technology and advanced manufacturing.