Cleanroom Cleaning Explained: ISO 14644 Classes

If your facility makes pharmaceuticals, medical devices, sterile products or food, the way you clean a controlled environment is not a matter of preference — it is a controlled, documented process tied directly to your room’s classification. Get it wrong and you risk contamination, failed environmental monitoring, and audit findings. This guide explains how cleanrooms are classified under ISO 14644 and EU GMP, and how the cleaning approach genuinely changes from one class to the next.

How cleanrooms are classified

A cleanroom is a space where airborne particle concentration is controlled to defined limits. The international standard for classifying that air cleanliness is ISO 14644-1, which rates rooms by the maximum number of particles (by size) permitted per cubic metre.

ISO 14644 classes (Class 5–9)

The lower the class number, the cleaner the room:

• ISO Class 5 — extremely clean, used for the most critical aseptic processing such as open exposure of sterile product.
• ISO Class 6 and 7 — common for filling support zones, device assembly and many controlled production areas.
• ISO Class 8 and 9 — used for less critical support areas, gowning rooms and general controlled space.

Each step up the scale permits more particles, so a Class 8 corridor and a Class 5 filling zone are cleaned to very different regimes.

EU GMP Grades A–D

In pharmaceutical manufacturing, the EU GMP Annex 1 framework adds Grades A, B, C and D. These map roughly onto ISO classes but, crucially, are defined for both the at-rest and in-operation states:

• Grade A — the critical zone for high-risk operations (aseptic fill, open product). Equivalent to ISO 5.
• Grade B — the background environment for Grade A aseptic work.
• Grade C and D — clean areas for less critical stages of manufacture.

In Australia, sterile-product manufacturers work to the PIC/S Guide to GMP, which the Therapeutic Goods Administration (TGA) adopts, so this grading is the practical reality for licensed sites here.

Why the cleaning approach changes with the class

A higher classification means tighter particle limits, which means more frequent cleaning, more controlled agents, and stricter technique. The cleaning regime should be derived from a risk assessment and validated — not copied from a generic schedule.

Frequency

Critical Grade A / ISO 5 zones are typically cleaned and sanitised before and after each operation, often with line clearance between batches. Lower-grade support areas may be cleaned daily or per shift, with periodic deep cleans. The cleaner the room, the shorter the interval.

Cleaning agents and rotation

Controlled environments use validated, low-residue detergents and disinfectants applied with sterile or low-particle-shedding wipes and mops. Higher grades commonly require:

• Sterile, filtered cleaning solutions in aseptic zones.
• Disinfectant rotation — alternating agents (including a periodic sporicidal agent) so resistant microorganisms are not selected for over time.
• Validated contact times — the surface must stay wetted for the full time the manufacturer’s data supports.

Technique: unidirectional cleaning

Method matters as much as product. The accepted discipline is unidirectional wiping — clean in a single direction with overlapping strokes, never a back-and-forth motion that redeposits contamination. Work from the cleanest area to the dirtiest, and from the top of the room (ceilings, then walls) down to the floor, so soil is always carried away from critical surfaces. Mop heads and wipes are changed frequently rather than rinsed back into the same bucket.

Contamination control and gowning

The biggest source of contamination in any cleanroom is people. Effective GMP & cleanroom cleaning depends on a full contamination-control system around the cleaning task:

• Gowning appropriate to the grade — from hairnets and shoe covers in lower grades up to sterile gloves, goggles, masks and full coveralls for Grade A/B work, donned in a defined sequence.
• Material and equipment flow — dedicated, colour-coded cleaning tools that never cross from a dirty zone into a clean one.
• Airlocks and pass-throughs used correctly to maintain pressure cascades.
• Documentation — every clean recorded, signed and dated so the activity is audit-ready.

For food manufacturing, the same control mindset underpins a HACCP plan and FSANZ requirements, even where the room is not formally ISO-classified.

Validation and documentation

Cleaning in a regulated environment must be demonstrably effective, not just performed. That means a written procedure, trained operators, defined agents and contact times, and verification through environmental monitoring — particle counts and microbial sampling — plus surface residue checks where relevant. The records are what an auditor reviews, so the paperwork is part of the job.

Cleanroom work also sits alongside ordinary commercial cleaning for the non-classified parts of a site, and the two should be coordinated so that gowning rooms, corridors and amenities support rather than undermine the controlled zones.

Talk to a regulated-industry cleaning partner

Getting cleanroom cleaning right takes a partner who understands classification, contamination control and the documentation auditors expect. Broadsafe Maintenance is ISO 9001 certified and delivers GMP and cleanroom cleaning for pharmaceutical, medical-device, food and manufacturing facilities across Greater Brisbane and Ipswich. To discuss your environment, contact us.