Guide
Cleanroom classes explained
ISO 14644-1 sets the airborne particle limit for each class. An ISO 7 room allows up to 352,000 particles of 0.5 µm or larger per cubic metre.
ISO 14644-1
Particle limits by class
| ISO class | Max particles ≥0.5 µm per m³ | Old FED-STD-209E name | Typical use |
|---|---|---|---|
| ISO 5 | 3,520 | Class 100 | Aseptic filling, critical zones |
| ISO 6 | 35,200 | Class 1,000 | Precision assembly |
| ISO 7 | 352,000 | Class 10,000 | Pharma support areas, device assembly |
| ISO 8 | 3,520,000 | Class 100,000 | Packaging, gowning, food production |
Typical uses are starting points, not requirements. Quoted in old US names? See Class 100, 10,000 and 100,000 cleanrooms explained.
EU GMP Annex 1
GMP grades and ISO classes
Classes below are defined by particles of 0.5 µm or larger. Annex 1 also sets limits for particles of 5.0 µm or larger and for microbial contamination.
| Grade | At rest | In operation |
|---|---|---|
| Grade A | ISO 5 | ISO 5 |
| Grade B | ISO 5 | ISO 7 |
| Grade C | ISO 7 | ISO 8 |
| Grade D | ISO 8 | Set by the user |
Questions
Common questions
What does ISO 7 mean?
An ISO 7 room allows up to 352,000 particles of 0.5 µm or larger per cubic metre of air, under ISO 14644-1.
Which class does my room need?
Your process, product and regulator decide. For pharmaceutical work, start from the GMP grade of each step, then map it to an ISO class.
Is a higher class always better?
No. A cleaner class needs more air and filtration, so it costs more to build and run. Specify only what the process needs.
How is the class confirmed?
By particle testing in the finished room, under the occupancy state agreed in the project.
Project enquiry
Send what you have
A room list, a floor plan or only the floor area is enough to start. After you submit, send drawings by email or WhatsApp.
We reply by email within one working day. We can sign an NDA before you send drawings.
WhatsApp +44 7962 561184 is our UK number for export enquiries. The factory is in Tianjin, China.
Email: [email protected]
WhatsApp: +44 7962 561184