The protocol should identify the cleanroom or clean zone boundaries, target ISO class, particle sizes and agreed occupancy state: as-built, at-rest or operational. For pharmaceutical facilities, ISO classification supports the qualification package but does not replace the GMP environmental monitoring strategy.

Room geometry and process boundaries should be clear before sample locations are assigned. Irregular spaces, large equipment footprints or separate clean zones may require documented subdivision and additional risk-based locations.

ISO 14644-1:2015 uses Table A.1 to determine the minimum number of sampling locations from the cleanroom area. The square-root formula associated with the 1999 edition should not be used for a 2015 protocol. The controlled standard should be consulted for the table, rounding and acceptance procedure.

Locations should be distributed to represent the area under classification. The protocol should preserve the approved map and explain how any obstruction or inaccessible point will be handled.

Annex A uses a minimum-volume calculation based on collecting enough air to detect at least 20 particles if the concentration were at the class limit for the largest considered particle size. The calculation uses the class concentration limit and converts cubic meters to liters. Additional minimum conditions in the standard must also be satisfied.

Theoretical sampling time equals volume divided by instrument flow rate. Project time must also include purge, probe positioning, room entry, location selection, cleaning, data review and invalid samples. A 100 LPM counter can reduce collection time for high volumes, but flow rate is not the only model-selection criterion.

Use a calibrated particle counter with controlled channels, location IDs, sample volume and time. Record probe orientation, tubing configuration, HVAC state, doors, equipment and personnel. Reports should retain raw counts, converted concentrations, alarms, deviations and the final classification conclusion for every location.

Lasair® Pro is available from Particle Measuring Systems in 25, 50 and 100 LPM configurations for cleanroom certification and monitoring. SAO NAM is the Authorized Sales & Service Center specializing in PMS Life Science applications in Vietnam and can support model selection, demonstration, qualification activities, training, calibration and maintenance according to project scope.

The classification protocol should clearly separate mandatory standard calculations from site-specific execution details. Include room boundaries, agreed occupancy state, ISO class, particle sizes, sampling-location map, rationale for subdividing irregular areas, instrument model and calibration status, probe orientation, tubing configuration, sample volume, acceptance logic and treatment of invalid samples. The report should preserve raw counts and converted concentrations for every location. Any deviation from the approved map or volume should be documented before the conclusion is issued. For pharmaceutical facilities, the ISO classification result should be evaluated together with GMP grade expectations, recovery studies, airflow visualization and the routine environmental monitoring strategy. Classification is a periodic state test; it is not evidence that all operational risks remain controlled between tests.

Before release, the site should confirm that the approved procedure, configured equipment, user training, raw data, review records and deviation process all describe the same workflow. Technical statements should be traceable to the current controlled standard or manufacturer document. Any site-specific limit, sampling duration or acceptance rule requires an approved rationale. Periodic review should compare the original assumptions with operating trends, changes, investigations and maintenance history. This final alignment is what allows a technically capable instrument or system to remain reliable and audit-ready throughout routine use.