CQV & QMS Knowledge Booklet · Module 1
Clean Room Design & Classification
What a classified room must achieve, and how that is specified, delivered and proven — from the invention of unidirectional airflow in 1962 to the Contamination Control Strategy that EU GMP Annex 1 made mandatory in 2022.
- ISO 14644-1
- EudraLex Vol. 4 Annex 1
- EN 1822
- ASTM E2500
- PIC/S PE 009
- Schedule M
A classified room is not a room that was once certified. It is a room whose performance is specified, delivered, proven and then re-proven on an interval — in the occupancy state that matters, against criteria that have changed more than once in the last decade.
This module follows that chain end to end: what the specification has to state, what qualification has to demonstrate, and where the line between good engineering practice and GMP qualification actually falls.
What this module covers
- Origins
- Whitfield's unidirectional cleanroom, NASA planetary protection, and the road from Federal Standard 209 to ISO 14644.
- Standards map
- Which body governs which aspect — ISO 14644 parts 1 to 7, Annex 1, EN 1822, Schedule M, PIC/S, ISPE, ASTM E2500.
- Occupancy states
- As-built, at rest and in operation — and why a classification certificate showing only at-rest data is incomplete for GMP.
- Particle classification
- ISO classes mapped against Annex 1 Grades A to D, for both particle sizes and both occupancy states.
- Microbial limits
- Annex 1 Table 2, why Grade A is "no growth" rather than "<1 CFU", and the four-hour settle plate rule.
- Sampling & requalification
- How many sampling locations, derived how — and the six-month and twelve-month maximum intervals that facilities quietly exceed.
- GEP versus GMP
- Which parts of a cleanroom are qualified, which are commissioned, and how to draw and defend that line.
- Pressure cascade
- Positive and negative cascades, and the three airlock types — cascade, bubble and sink — with the risk each one answers.
- Air change rates
- Why Annex 1 abandoned fixed ACH tables, and what has to be justified in their place.
- Recovery & CCS
- The clean-up period, and what separates a Contamination Control Strategy that reasons from one that merely catalogues.
- HEPA filtration
- Most Penetrating Particle Size, EN 1822 H13/H14 against the US 99.97 % convention, and installed-seal scan testing.
- Finishes & flow
- Coving, service penetrations, disinfectant compatibility, and unidirectional personnel and material flow.
- Gowning
- Why Annex 1 treats Grade A and B gowning as a qualified activity, performed and requalified per individual.
- URS to OQ
- What the specification must state, what Installation Qualification verifies, and what Operational Qualification must execute.
Questions this module answers
- Your latest classification certificate shows at-rest data only. Is the room compliant?
- Your protocol sets the Grade A microbial criterion at "<1 CFU". Is that still correct?
- Your filter schedule says "HEPA 99.97 %". Is that the same thing as H14?
- When was your last Grade B requalification — measured test date to test date?
Also in this series
All modules