What ISO Class Does Your Cleanroom Need
- zachsievert15
- Aug 19
- 4 min read
When planning a new cleanroom or clean room project, one of the biggest decisions is choosing the right ISO Class. The classification you select determines everything from air filtration requirements to construction costs and long-term maintenance. Picking too low of a classification can risk product quality, while going too high can lead to unnecessary expenses. So how do you know which ISO Class is the right fit for your operation? Let’s break it down in clear, simple terms.
Table of Contents
Understanding ISO Classifications
ISO Class refers to the international standards for cleanrooms that control airborne particle concentrations. The ISO 14644-1 standard is the global benchmark for measuring and categorizing how clean a controlled environment needs to be. These classifications range from ISO Class 1 (the cleanest) to ISO Class 9 (the least strict). Each class defines acceptable levels of airborne particles per cubic meter of air, creating a universal system for consistency.
For example, an ISO Class 5 clean room allows only 3,520 particles of 0.5 microns or larger per cubic meter. In contrast, an ISO Class 8 cleanroom permits up to 3,520,000 particles of the same size. This difference illustrates how significantly the standards vary across industries and applications, highlighting why careful selection is critical.
How Cleanroom Standards Are Defined
Cleanroom standards are based on particle count measurements. Highly sensitive industries like pharmaceuticals, aerospace, and semiconductor manufacturing require very tight control of contaminants. By contrast, sectors like plastics manufacturing or automotive parts may need less strict standards, though they still rely on clean room conditions to prevent defects.
The ISO classifications also align with older standards, such as Federal Standard 209E in the United States. Although FS 209E is no longer active, many engineers and cleanroom contractors still reference its terms like “Class 100” or “Class 10,000” as shorthand.
Cleanroom Classification by Industry
Different industries often require specific ISO Classes to ensure compliance, safety, and product quality:
Pharmaceuticals and Biotechnology: Typically require ISO Class 5 to ISO Class 7 for sterile drug manufacturing and packaging. Regulatory agencies like the FDA often demand strict cleanroom certification and documentation.
Medical Device Manufacturing: Many operations fall within ISO Class 7 or ISO Class 8, depending on the sensitivity of the product and production workflow.
Semiconductors and Electronics: These applications demand extreme cleanliness, often ISO Class 3 to ISO Class 5. Tiny particles can ruin delicate circuitry or compromise yields.
Food and Beverage: Controlled environments around ISO Class 8 are commonly used in packaging and processing areas to prevent contamination and extend shelf life.
Aerospace: Clean rooms in aerospace frequently range between ISO Class 5 and ISO Class 7 to protect highly sensitive components.
Understanding these industry benchmarks helps narrow down the right classification for your own project and ensures regulatory alignment.
Key Factors in Determining the Right ISO Class
Selecting the appropriate ISO Class involves more than copying what another business uses. Several factors should be evaluated carefully:
Product Sensitivity: The more delicate or sterile your product, the higher the classification needed to maintain safety and performance.
Regulatory Compliance: Government or industry-specific regulations often dictate the minimum ISO Class you must meet.
Budget and Resources: Higher classes require more investment in construction management, equipment, and ongoing operational costs.
Workflow and Personnel: The number of people working inside and the type of activities performed influence contamination levels.
Future Scalability: Designing for slightly stricter standards may be wise if you anticipate tighter regulations, new products, or technology shifts.
Balancing these factors ensures your cleanroom design is both practical and cost-effective for long-term success.
The Role of Cleanroom HVAC and Air Filtration Systems
One of the most critical elements of maintaining ISO Class standards is the cleanroom HVAC system. Specialized HVAC design keeps air pressure, temperature, and humidity within tight tolerances.
Air filtration systems, especially HEPA and ULPA filters, remove particles from the air before circulation. Depending on the ISO Class, you may need laminar airflow systems that push filtered air uniformly through the space to minimize turbulence and prevent buildup. In addition to particle control, cleanroom HVAC also supports energy efficiency, sustainability, and ensures comfort for personnel working inside controlled environments.
Construction and Certification Considerations
Choosing the right ISO Class directly impacts cleanroom construction. A stricter classification means higher requirements for materials, sealing, flooring, and finishes. Even details like the type of doors, lighting, and pass-through chambers must align with cleanroom standards and certification guidelines.
Once construction is complete, the space must undergo cleanroom certification. This process includes testing airflow, verifying filtration, and measuring particle counts to ensure the environment matches the intended ISO Class. Certification is not a one-time event—periodic testing and monitoring are required to maintain compliance and operational reliability.
Why ISO Class Matters for Long-Term Operations
The ISO Class you select influences more than the initial build. It affects day-to-day operations, maintenance costs, and even future expansion or relocation. A facility with the right ISO classification can reduce risks of contamination, improve product quality, and protect your brand reputation. On the other hand, choosing an ISO Class that is either too strict or too relaxed can lead to wasted money or regulatory issues. For businesses with wastewater management concerns, proper classification also helps ensure environmental safety during production processes and disposal practices.
DesignTek Consulting and Your Cleanroom Project
At DesignTek Consulting, we understand how challenging it can be to determine the right ISO Class for your operation. From cleanroom design and HVAC engineering to construction management and cleanroom certification, we help clients create efficient controlled environments that meet industry and regulatory standards. We offer a wide range of services to help take your business to the next level.
Whether you’re planning a pharmaceutical facility, semiconductor lab, or manufacturing plant, our expertise in air filtration systems, cleanroom construction, and compliance can guide you every step of the way. If you’re ready to explore what ISO Class your cleanroom needs, contact us at DesignTek Consulting. Our team is here to ensure your facility meets the right standards while supporting efficiency and long-term growth.