A cleanroom checklist is the working document a facility uses to verify, on a recurring schedule, that a controlled environment still meets the ISO 14644-1 particle-count classification, filtration integrity, airflow, and personnel-behavior requirements it was originally qualified against. It is narrower and more operational than a full GMP facility audit checklist, which covers the entire quality system (documentation, deviations, training, supplier qualification) rather than the physical performance of one controlled space. Use this checklist alongside, not instead of, a GMP audit program.
What a cleanroom checklist needs to verify
Whether the checklist is run by internal QA, a contract certification vendor, or during a regulatory inspection, it is built around six categories of evidence. Each is described below with the specific check items a facility should be able to produce records for.
1. Classification and particle counts (ISO 14644-1)
The starting point of any cleanroom checklist is confirming the room still performs at its designated ISO class. ISO 14644-1:2015 defines maximum permitted airborne particle concentrations at specific particle sizes for each of nine classes (ISO 1, the cleanest, through ISO 9). Most pharmaceutical, biotech, and medical-device cleanrooms operate at ISO 5 through ISO 8; see Cleanroom Classifications: ISO 14644-1 and the FED-STD-209E Equivalents for the full class table and the retired FED-STD-209E “Class 100/10,000/100,000” equivalents still referenced informally in the US, and ISO Class 7 Cleanroom Requirements for a worked example at one common classification.
- Non-viable particle counts measured at ≥0.5 µm and ≥5 µm (additional smaller size thresholds apply at ISO 6 and cleaner) using a calibrated discrete-particle counter, sampled at defined locations and volumes per ISO 14644-1 Annex A
- Counts recorded against the room’s documented “as-built,” “at-rest,” or “operational” occupancy state — these are not interchangeable and the checklist should record which state was tested
- Results compared against the room’s own qualification limits, not just the generic ISO table, since a room may be qualified tighter than its nominal class
2. Filtration and airflow integrity
Particle counts only stay in spec if the filtration and airflow system delivering that air is intact. See HEPA Filter Certification for Cleanrooms and Controlled Environments for the full filter-integrity testing methodology.
- HEPA (or ULPA) filter integrity — photometer or aerosol-challenge scan test confirming no leaks above the applicable penetration threshold at the filter face and frame seal
- Airflow velocity at the filter face (for unidirectional/laminar-flow zones) or air changes per hour (for turbulent/non-unidirectional rooms), measured against the room’s qualified design range
- Recovery time — how quickly the room returns to its classified particle level after a deliberate disturbance, where the qualification protocol calls for it
- Room pressure differentials against adjacent spaces, confirming the intended cascade (higher-classified spaces held at positive pressure relative to lower-classified or unclassified adjacent areas) is intact, with continuous or periodic differential-pressure gauge readings logged
- Any localized unidirectional-airflow equipment inside the room — laminar flow hoods, biosafety cabinets — checked against its own separate certification schedule; see Laminar Flow Hood Certification and the biosafety cabinet definition for how cabinet certification differs from room certification
3. Requalification interval
ISO 14644-2 sets the monitoring/requalification schedule tied to classification: cleaner classifications (ISO 5 and below) are conventionally requalified on a shorter cycle — commonly every six months — while less stringent classifications (ISO 6 through ISO 9) are typically requalified annually. Facilities operating under GMP (EU GMP Annex 1, FDA guidance) or pharmacy compounding standards (USP <797>/<800>) may have a tighter interval specified by their own quality system or applicable regulation than the ISO baseline — the checklist should record which standard’s interval actually governs the room in question, and confirm the most recent requalification date against it before anything else on the checklist is meaningful.
4. Viable (microbial) monitoring
Non-viable particle counts and viable (microbial) monitoring are separate disciplines and a complete checklist tracks both:
- Settle plates (passive air sampling) exposed for a defined duration at fixed locations
- Active air sampling (volumetric air samplers) at locations and frequencies defined by the room’s environmental monitoring program
- Surface monitoring — contact (RODAC) plates and/or swabs on equipment, walls, and work surfaces
- Personnel monitoring — glove prints and gown-surface sampling at the end of critical operations
- Action and alert limits specific to the room’s grade/class, with a documented investigation trigger when a result exceeds either
GMP-regulated cleanrooms (EU GMP Annex 1, which governs sterile medicinal product manufacture) map viable and non-viable limits to Grades A through D rather than ISO classes directly — a checklist for a GMP-regulated room should reference the applicable grade limits, not only the ISO 14644-1 table. See Good Manufacturing Practice (GMP): A Guide for Research Institutions for how GMP grading interacts with ISO classification.
5. Gowning and personnel qualification
- Gowning procedure documented and posted, with the correct sequence for the room’s classification (higher classes generally require more gowning stages — undergarments, coveralls, hoods, boot covers, sterile gloves, and in the cleanest rooms, face masks or full-coverage suits)
- Personnel gowning qualification on record — an initial qualification plus periodic (commonly annual) requalification via glove-print and gown-surface sampling immediately after gowning
- Training records current for everyone with unsupervised access, including visitors and contractors who enter for maintenance
- Behavioral controls observed during the walkthrough — no uncovered skin, no cosmetics/jewelry under garments, controlled entry/exit sequencing through airlocks or gowning rooms
6. Cleaning, disinfection, and change control
- Cleaning and disinfection schedule current, with rotation between disinfectants (and a periodic sporicidal agent) to prevent resistant-organism buildup, per the room’s documented program
- Cleaning records signed and retained, distinguishing routine cleaning from post-event or post-maintenance cleaning
- Change control on record for any modification to the room, its HVAC, or its equipment since the last qualification — an undocumented change is one of the most common findings that triggers a full requalification rather than routine monitoring
- Calibration records current for every instrument used to generate checklist data itself (particle counters, differential-pressure gauges, air velocity meters, thermo-hygrometers)
How a cleanroom checklist differs from a GMP audit checklist
The two overlap but answer different questions. A GMP audit checklist asks whether the facility’s whole quality system — documentation, deviation handling, training, supplier qualification, change control governance — is functioning as designed, across an entire site or program. A cleanroom checklist asks a narrower, more physical question: does this specific controlled space still perform at its qualified classification right now. A GMP audit will typically reference cleanroom qualification records as one line item among many; the cleanroom checklist is what generates the records the audit is checking.
Frequently asked questions
How often should a cleanroom be requalified?
ISO 14644-2 ties the interval to classification: cleaner rooms (ISO 5 and below) are conventionally requalified roughly every six months, and less stringent rooms (ISO 6 through ISO 9) roughly every twelve months. A facility’s own quality system, or an applicable regulation such as EU GMP Annex 1 or USP <797>/<800>, can require a shorter interval than the ISO baseline — whichever is shorter and applicable governs.
What’s the difference between viable and non-viable particle monitoring?
Non-viable particle counting measures total airborne particles of a given size regardless of whether they are biological, using a calibrated particle counter — this is what ISO 14644-1 classification is based on. Viable (microbial) monitoring specifically detects living organisms via settle plates, active air samplers, and surface/personnel sampling, and is evaluated separately against its own action/alert limits.
Does a cleanroom checklist replace a GMP facility audit?
No. A cleanroom checklist verifies the physical performance of one controlled space (classification, filtration, airflow, monitoring). A GMP audit evaluates the entire quality system a facility operates under. Regulated facilities need both, and the cleanroom checklist’s records are typically evidence reviewed during a GMP audit rather than a substitute for one.
Who is qualified to certify a cleanroom?
Certification testing (particle counts, HEPA filter integrity, airflow, pressure) is typically performed by a qualified internal metrology/facilities team or a third-party certification vendor using calibrated instruments and a documented protocol, often referencing IEST or ISO 14644 test methods. The checklist itself — confirming the certification is current and reviewing monitoring trends — is commonly owned by QA.
