Clean room molding is required for manufacturing plastic products that require contamination control. These products may be sensitive to particulate, microbial, or other airborne contaminants that may impact safety, regulatory compliance, or performance. Engineers often default to cleaner is safer when specifying clean room injection molding. While that thought process is understandable, over specifying cleanliness can unnecessarily drive up costs. ISO Class 7 is one of the most commonly used cleanroom classifications for molded plastic components, particularly when contamination control is important but full aseptic conditions are not.
What Is Clean Room Molding?
Clean room molding requires stricter environmental controls that must meet specific airborne particle levels. Cleanrooms are classified according to ISO 14644-1 Cleanrooms and Associated Controlled Environments, which defines air cleanliness by the concentration of airborne particles per cubic meter at specific particle sizes. ISO classifications range from Class 1 (extremely clean) to Class 9 (the least stringent). Some manufacturers also reference the older Federal Standard 209E classification system, which uses terms like Class 10,000. These numbers refer to the maximum number of 0.5-micron particles allowed per cubic foot of air.
A Class 7 clean room (equivalent to the old Class 10,000 standard) permits a maximum of 352,000 particles (0.5 microns or larger) per cubic meter of air and 60 air changes per hour. For comparison, Class 8 clean rooms (equivalent to the old Class 100,000 standard) allow up to 3,520,000 particles (0.5 microns or larger) per cubic meter and have 20 air changes per hour.
Clean room molding environments share several technical and procedural elements that go beyond standard molding floors.
Air quality and filtration features in clean rooms:
- HEPA‑filtered supply air removes a high percentage of airborne particles before they enter the cleanroom.
- Positive pressure or airlock systems keep unfiltered air from flowing into the controlled space.
- Air changes per hour (ACH) are specified by class.
- Particle counts are monitored, and rooms are cleaned regularly to verify that the room stays within its ISO classification limits.
- Employee PPE and attire are more stringent than normally required PPE, including strict gowning procedures.
Why ISO Class 7 Is Commonly Used for Injection Molding
Injection molding introduces contamination risk from several sources, including airborne particles, operator interaction, material handling, and mold open time. ISO Class 7 addresses these risks without the operational and cost burden of cleaner rooms.
The primary benefits of ISO Class 7 molding include:
- Controlled particulate environment: ISO Class 7 limits airborne particles large enough to affect surface finish, cosmetic appearance, sealing features, and fit-critical geometries.
- Reduced bioburden risk without claiming sterility: While ISO 14644 is a particle count standard, lower particle counts correlate with lower microbial transport in air, which matters for medical and pharma-adjacent components.
- Cost control at scale: Each step cleaner significantly increases operating costs due to filtration, monitoring, validation, and personnel controls. ISO Class 7 is often the point at which contamination risk is reduced enough without incurring unnecessary overhead.
Industries That Commonly Use ISO Class 7 Clean Room Molding
ISO Class 7 is widely used where cleanliness affects performance or compliance, but where full sterility is not required at the molding step.
Medical Devices
- Non-implantable devices
- Diagnostic housings
- Surgical disposables before sterilization
- Drug-delivery components not filled in the clean room
Pharmaceutical and Biotech Support Components
- Packaging components
- Delivery system housings
- Disposable fluid-path components before sterilization
Electronics and Precision Industrial Components
- Optical and sensor housings
- Connectors and interfaces
- Parts sensitive to surface contamination or particulate interference
When ISO Class 7 May Not Be Enough
While ISO Class 7 clean room molding is an ideal solution for many plastic components, it is not a universal solution. It may be insufficient if:
- The part has an exposed sterile fluid path during molding, and terminal sterilization is not used
- Sub-micron particles directly affect function (optics, microfluidics)
- Regulatory requirements explicitly call for ISO Class 5 or aseptic processing
- Bioburden limits must be actively controlled rather than indirectly reduced
Trust Triad’s Expertise in Clean Room Injection Molding
At Triad Plastic Technologies, our team specializes in delivering precision injection molded components for industries where clean room molding is essential. We offer advanced solutions with cleanliness levels up to ISO Class 7, utilizing state-of-the-art equipment with clamping pressures ranging from 138 to 385 tons. Our commitment to quality is demonstrated by our ISO 9001:2015 and ISO 13485:2016 certifications, which ensure that every part meets stringent standards.
Contact us today to learn how Triad Plastic Technologies can support your next project with industry-leading expertise and uncompromising quality.