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Setting the Standard: An Inside Look at ISO Cleanroom Classifications

Cleanrooms play a pivotal role in various industries, ensuring that products and processes are not compromised by contaminants. Take the likes of businesses in food processing sector, especially those dealing with sensitive products like infant formula and dairy. Or in the electronics industry, where the manufacture of microchips and LCD displays can only be done with stringent contamination control. Over in the field of optics, the creation of lenses and other optical components can easily be ruined by minute speck of dusts. What measures should the businesses put in place when designing their production plants?

ISO standards help industries maintain consistency and reliability in their processes by setting clear benchmarks for cleanliness. They provide a common language and a set of expectations that facilities worldwide can aim for and achieve. This makes them vital in safeguarding the integrity of products, protecting the workforce, and upholding the reputation of industries that rely on ultra-clean environments.

Laboratory tech disinfecting hands

Understanding ISO Cleanroom Classifications

What is ISO 14644-1?

ISO 14644-1 is essentially a rulebook that dictates how clean your cleanroom should be. It’s a journey started in the late 1990s when the Institute of Environmental Sciences and Technology (IEST) rallied behind the American National Standards Institute (ANSI) in urging the ISO to craft a universal standard intended for global implementation.

Different countries had their own standards, making international collaboration a bit tricky. These included:

  • United States: The Federal Standard 209E was widely used in the U.S. It was officially canceled and superseded by ISO 14644-1 in the year 2001.

  • United Kingdom: The British Standard 5295 was in place, providing guidelines for cleanroom classification and specifying cleanliness levels based on particle counts. It was withdrawn in 2007, replaced by the suite of ISO standards.

  • Japan: The Japanese Industrial Standard (JIS) had its own cleanroom classification system, providing criteria for air cleanliness and other factors. Over time, the international adoption of ISO 14644-1 has influenced cleanroom practices in Japan as well, although JIS standards are still referenced.

The establishment of ISO 14644 set a consistent framework for cleanroom classification worldwide. It made it easier for industries across different regions to collaborate, ensuring that products met the same high standards regardless of where they were produced.

Other standards have built on it, like the case for VDI 2083 in Germany. This is a comprehensive set of national guidelines developed by the Association of German Engineers (Verein Deutscher Ingenieure, VDI) that provides additional depth and addressing specific issues like energy and cost efficiency, as well as certain industry-specific considerations not extensively covered in the ISO standards.

While VDI 2083 holds particular sway in Germany, it has also been adopted by Austria and Switzerland to enhance regional standardization efforts. In international contexts, businesses still need to be aware of the specifications from the ISO family of standards to ensure comprehensive adherence to cleanroom best practices.

Breakdown of ISO Cleanroom Classes

ISO 14644-1 categorizes cleanrooms into nine classes, from ISO 1 to ISO 9, based on the number and size of particles allowed per cubic meter of air.

  • ISO 1 is the cleanest class. It’s almost like a sci-fi level of cleanliness, with a maximum of only two particles per cubic meter for the smallest size measured. You’ll find this class in industries where even a speck of dust could spell disaster, like semiconductor manufacturing or nanoparticle research.

  • Moving on to ISO 2 to ISO 4, these are still extremely clean environments, with a particle count ranging from a maximum of 100 to 10,000 for the smallest particles. These are common in precision manufacturing and pharmaceuticals.

  • ISO 5 to ISO 7 are the middle ground and are seen in various industries, from aerospace to biotech. For example, an ISO 5 cleanroom allows up to 100,000 particles of the smallest size. It’s clean, but there’s a bit more room for particles.

  • ISO 8 and ISO 9 are at the lower end of the cleanliness scale. But don't be fooled, an ISO 8 cleanroom is still cleaner than a regular room. These classes are suitable for industries where the risk of contamination is less critical, such as in some types of food packaging or precision machinery assembly.

ISO Classification Chart

Each class’s requirements are precisely defined, specifying the maximum allowable particle count, the maximum size of those particles, and the required level of cleanliness. We covered them in detail here.

ISO 14644-2 Overview: Monitoring Air Cleanliness in Cleanrooms

In industries where a speck of dust can ruin a product, or a slight change in air quality can lead to contamination, there’s no room for error. ISO 14644-2 focuses on the regular monitoring of cleanrooms, ensuring they consistently meet the required air cleanliness levels. It sets out the requirements for ongoing monitoring, specifying how often you should test, what you should test for, and how you should do it.

Think of it as your cleanroom’s health check. Regular monitoring under ISO 14644-2 helps in catching any potential issues before they become major problems. It ensures that the cleanroom is performing as it should, and if it's not, it’s a red flag that something needs to be fixed.

Compliance with ISO 14644-2 is about maintaining the integrity of the cleanroom, ensuring product quality, and protecting both your investment and your reputation. That way you’re always on top of things, ensuring that your cleanroom is doing exactly what it needs to do.

Other Relevant ISO Standards for Cleanrooms

Maintaining a cleanroom involves a suite of ISO standards. While ISO 14644-1 and ISO 14644-2 play foundational roles, several other standards are crucial for comprehensive cleanroom validation and monitoring, such as:

  • ISO 14644-3: This standard focuses on test methods, helping facilities validate and monitor cleanroom performance and functionality. It covers various aspects of testing, including airborne particle concentrations and airflow patterns.

  • ISO 14644-4: It lays down the requirements for the design and construction of cleanroom and clean air devices, as well as the requirements for start-up and qualification.

  • ISO 14644-5: This one provides the basic requirements for cleanroom operations, ensuring that daily activities don’t compromise the cleanroom’s integrity. It's about maintaining the standard once it's achieved.

  • ISO 14644-6: This standard outlines the terms, definitions, and conventions used in the rest of the ISO 14644 series, ensuring clear communication and understanding across all parties involved.

Such standards collectively ensure that cleanrooms function at their best, preventing contamination and ensuring product quality. They cover everything from the nitty-gritty of daily operations to the big picture of design and construction. It’s about creating a controlled environment and keeping it that way. Adhering to these standards protects the end-user as well, whether they’re taking a medication, using a tech device, or flying in an aircraft.

Real-World Applications of ISO Cleanroom Standards

How are different sectors utilizing these standards?

Pharmaceuticals and Healthcare

Laboratory personnel in cleanroom

Medications and vaccines are formulated in environments where contamination can directly affect the product's safety and efficacy. Cleanrooms of ISO Class 7 or 8 are commonly employed, though more sensitive processes, such as sterile drug manufacturing, may require ISO Class 5 conditions.

Take the case of insulin-production for instance, a life-saving drug for diabetics. The manufacturing process involves various biological materials that could be compromised by contaminants. Here, ISO cleanroom standards ensure that every vial of insulin is free from particulates, ensuring patient safety and product consistency.

Semiconductor Industry

When it comes to manufacturing semiconductor devices, even a single particle can wreak havoc, potentially causing defects in microchips. Cleanrooms in this industry typically adhere to stricter standards, often ISO Class 3 or 4.

Companies invest heavily in sophisticated filtration systems and regular monitoring, ensuring that the cleanrooms meet and maintain the necessary ISO standards. This not only enhances product yield but also significantly reduces the risk of expensive product recalls.


Contamination in this sector isn’t just costly—it could be catastrophic. Components like satellite sensors or spacecraft cameras require assembly in ISO Class 5 or even Class 4 environments.

By adhering to ISO standards, aerospace companies can mitigate the risks of component failure in space, where there are no second chances. It’s about ensuring reliability and precision, whether for commercial satellites or critical space exploration missions.

Getting Through Certification and Compliance Process

So, how do you get started?

  1. Understand the Specific Requirements: Before anything else, you’ll need to know exactly what ISO classification your cleanroom needs to meet. This depends on the type of work you’re doing and the level of cleanliness required. Refer to ISO 14644-1 for the classification details.

  2. Consult with a Cleanroom Design Expert: They can assess your needs, help design your cleanroom to meet ISO standards, and guide you through the certification process.

  3. Implement Proper Cleanroom Practices: Even the best-designed cleanroom won’t stay compliant if proper practices aren’t followed. Ensure all staff are trained, and procedures are in place to maintain cleanliness.

  4. Schedule Routine Testing and Monitoring: ISO 14644-2 emphasizes the importance of ongoing monitoring to maintain your cleanroom’s certification. Plan regular tests for particle count and other contaminants.

  5. Prepare for Certification Audit: An independent certification body will conduct an audit to ensure compliance. Make sure all documentation is in order, practices are being followed, and your cleanroom meets the required standards.

  6. Pick a Top-Tier Certification Body: Choose a certification body that's recognized national or international accreditation organization – like the United States, there’s the ANSI-ASQ National Accreditation Board (ANAB), and in Europe, organizations like UKAS in the United Kingdom serve a similar function. The certification body should be experienced in your industry niche to guide you through the specific tests and paperwork you need.

Tips For Regular Testing and Monitoring

Engineer working on a microchip in cleanroom

After you get certified, you still need to ensure your cleanroom continues to meet the ISO standards. For this, work with the correct and calibrated instruments for measuring particle counts, airflow, temperature, and humidity. Also stick to a steady schedule – a routine that suits your cleanroom's unique needs and ISO standards.

Document every test and monitoring session. This practice is essential for tracking your progress over time and showing your compliance when audit time rolls around. And make sure that the team responsible for monitoring knows exactly what they’re doing. Proper training is key.

Act on the data you obtain, Use it to make informed decisions and implement changes whenever necessary. In addition to continuous monitoring, schedule audits to ensure that all systems are functioning as they should.

Companies that comply with these ISO cleanroom standards provide reassurance to clients and stakeholders that their products are manufactured, tested, and handled in a pristine environment – and avoid potential penalties or legal issues. With the tests and monitoring, problems are addressed before they blow up, nipping them in the bud. If done regularly, the tests lead to process optimizations, which in turn translates to efficient use of resources – saving you more money in the long run.

If you are in need of an iso certified cleanroom, Contact us to see how DesignTek Consulting Group can assist in bringing your vision to life.


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