A cleanroom controls airborne particles and micro-organisms to an extremely strict standard. In semiconductor and display production lines, bio and pharmaceutical plants and food GMP facilities, the wrong insulation can mean particle contamination, mould growth or a failure to meet fire requirements — and a facility certification can be withdrawn. There are good reasons why ordinary insulation cannot simply be used as it is.
Four requirements for cleanroom insulation
| 1. Low particle shedding | No particles may be released from the insulation surface. Materials that shed fibers or powder cannot be used. |
| 2. Non-combustible or semi-non-combustible | Minimising toxic gas and smoke spread in a fire. Many cleanroom zones mandate non-combustible materials. |
| 3. Antimicrobial and non-contaminating | Denying mould and bacteria a foothold. Food and pharmaceutical GMP facilities need certified antimicrobial products. |
| 4. Low water absorption | Moisture uptake degrades performance and risks microbial growth. Closed-cell materials are the advantage here. |
ISO 14644-1 cleanroom classes (particles per m³)
ISO 14644-1 classifies cleanroom cleanliness by the number of fine particles (at 0.5 μm) permitted per cubic metre of air. The lower the class number, the stricter the standard — and the stricter the limits on insulation shedding.
| ISO Class 5 (formerly Class 100) | 3,520 particles of 0.5 μm per m³ or fewer — core semiconductor processes, zero-shedding materials essential |
| ISO Class 6 (formerly Class 1,000) | 35,200 per m³ or fewer — semiconductor back-end and OLED, low-shedding non-combustible materials |
| ISO Class 7 (formerly Class 10,000) | 352,000 per m³ or fewer — pharmaceutical and bio, antimicrobial semi-non-combustible materials |
| ISO Class 8 (formerly Class 100,000) | 3,520,000 per m³ or fewer — food GMP and general cleanrooms, non-contaminating materials |
💡ISO Class 1–4 front-end zones are controlled on 0.1 μm particles (Class 1: 10 per m³, Class 4: 10,000 per m³), and insulation cannot be used exposed there unless the facing is completely sealed.
Insulation requirements by ISO class
| ISO Class 1–4 (semiconductor front end) | Zero shedding essential. Non-combustible materials only. Sealing mandatory. Exposed glasswool and mineral wool prohibited. |
| ISO Class 5–6 (semiconductor back end, OLED) | Low-shedding materials essential. Non-combustible or semi-non-combustible. Sealed facing recommended. |
| ISO Class 7–8 (pharma, bio, food) | Antimicrobial, non-contaminating materials essential. Must meet GMP. Semi-non-combustible or better. |
| GMP / HACCP facilities (food, pharma) | FDA-compliant materials recommended. A smooth surface (denying bacteria a foothold) is essential. |
Recommended insulation by cleanroom type
Semiconductor and display cleanrooms (ISO 1–6)
- PIR urethane pipe insulation with sealed aluminum facing — no shedding, semi-non-combustible available (λ 0.020–0.023 W/m·K)
- Aerogel blanket with an aluminum jacket — where space is tight, high performance at low thickness (λ 0.013–0.020 W/m·K, the industry's lowest)
- Glasswool board with completely sealed aluminum facing — no shedding provided the facing is intact (λ 0.032–0.040 W/m·K)
- Caution: glasswool and mineral wool must never be installed exposed without facing — fiber release causes contamination
- Inside ductwork: non-combustible materials only, with facing joints fully sealed with aluminum tape
Pharmaceutical and bio GMP cleanrooms (ISO 7–8)
- Basofoam pipe insulation — antimicrobial, non-contaminating and FDA compliant, the strongest recommendation
- PIR urethane pipe insulation with PVC facing — semi-non-combustible, low absorption, condensation control
- Aerogel — for cryogenic pharmaceutical storage lines (liquid nitrogen and similar)
- Surface finish: smooth PVC or stainless steel facing, minimising conditions for bacterial growth
- Complete joint sealing is essential — blocking moisture ingress and mould growth
Food plants (HACCP)
- Basofoam — non-contaminating, non-toxic and FDA compliant, the standard material for food environments
- Rubber foam (flame-retardant treated) — condensation control on chilled and refrigeration lines
- Stainless steel facing — washable and corrosion resistant
- Orient joints on the underside of pipework downward — minimising moisture ingress
What must not be used in a cleanroom
| Exposed glasswool | Fiber shedding generates particles — absolutely prohibited in cleanrooms (usable only with completely sealed facing) |
| Standard EPS | Combustible and particle-generating — unusable in cleanrooms |
| Untreated rubber foam | A fire risk if not flame-retardant treated, and fails GMP |
| Insulation with damaged facing | Must be replaced immediately once the fiber inside is exposed |
Installation points
- Seal every joint and overlap completely with aluminum tape or heat-shrink sleeving
- Clean the surface after installation (air blow and wipe) to remove particles generated during the work
- Cleanroom garments and gloves are mandatory for work inside the cleanroom
- Store insulation protected from dust and contamination, keeping it wrapped
- Inspect regularly for damaged or lifting facing, and repair immediately
💡Tell us the cleanroom class, the pipe duty (chilled water, hot water, chemicals, gas) and the service temperature, and we will recommend insulation meeting the ISO class and GMP requirements. We have extensive delivery experience in semiconductor, pharmaceutical and food plants. Technical advice: +82 10-4266-9745
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