Your Complete Source for ISO 14644-1:2015 Particle Counting Information

ISO 14644-1:2015 continues to pose challenges to cleanroom managers and manufacturers. Here we provide several sources of information to help everyone from those new to this ISO regulation to veterans in the field. 

Get a summary of ISO 14644-1:2015 by reading the paper below or watching the recorded webinar at the right. 

Read the papers below to learn about the closely relevant ISO 21501-4 calibration standards and how they apply to you. 

Have a question? Read some of the frequently asked questions we get (see the bottom right), or submit your own question for one of our experts. 

Do you need an ISO 14644-1:2015 compliant product that is supported with ISO 21501-4 calibration? If yes, see our list of products at the bottom. 

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Knowledge / Papers

ISO 14644-1:2015 Revisions Summary

ISO 14644-1:2015 Revisions Summary

The recent revision of ISO 14644-1:2015 has introduced several changes for cleanroom classification and monitoring guidelines. This paper will highlight the major changes in the new ISO 14644-1 compared to the previous version, as well as the possible impact on the Pharmaceutical EU GMP Annex 1 and FDA Aseptic Processing Guideline.

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Understanding ISO 14644-2:2015 Cleanroom Monitoring [Webinar Presentation]

ISO 14644-2:2015 is not only a new standard with which to be compliant, but is also a beneficial tool to use in achieving mature cleanroom environmental control.

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Common ISO 14644-2:2015 Questions and Answers

The recently updated ISO14644-2:2015 has caused some confusion and raised concerns by companies who want to ensure that they are fully compliant. To address these issues, Particle Measuring Systems is sharing our industry expertise providing you with answers to many of the questions that our customers frequently ask.

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Understanding ISO 14644-2:2015 Cleanroom Monitoring

This document underlines the major changes between the previous version of ISO 14644-2 and the latest,
second edition, dated December, 12th 2015. A specific approach to the best practices to be adopted for an
efficient and compliant cleanroom monitoring process are discussed.

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ISO 14644-1:2015 Frequently Asked Questions (FAQs)

The newly updated ISO14644-1:2015 has caused some confusion and raised concerns by companies who want to ensure that they are fully compliant. To address these issues, Particle Measuring Systems is sharing our industry expertise and have provided an ISO 14644-1:2015 summary paper, an on-demand webinar, and are now providing you with answers to many of the questions that our customers frequently ask.

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Are your particle counters ISO 14644-1 compliant?

Are your particle counters ISO 14644-1 compliant?

Are your particle counters ISO 14644-1 compliant and able to be calibrated to all required tests according to ISO 21504-4?

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ISO 14644-1:2015 Compliant Products
Supported by ISO 21501-4 Certified Calibration


Lasair® III Airborne Portable Particle Counter

Lasair® III Airborne Portable Particle Counter

Sets the standard for portable aerosol particle counters and meets the requirements of ISO 14644-1:2015 and  ISO 21501-4

IsoAir 310P Particle Sensor

IsoAir 310P Particle Sensor

Real-time particle monitoring gives quick notification of particle anomalies, detecting 0.5 and 5.0 µm for GMP and FDA compliance.

FacilityPro® Software

FacilityPro® Software

FacilityPro Software provides the interface, data management, and reporting for an environmental monitoring...

Airnet II(s) 2 Channel Air Particle Sensors

Airnet II(s) 2 Channel Air Particle Sensors

Meets the specifications of ISO 21501-4 to measure the size and number of particles suspended in the air for real-time monitoring of defect-causing particles.

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PMS Provides Certified Compliant Service

Service Repair & Calibration

Service Repair & CalibrationAt Particle Measuring Systems we have strict processes and standards in place to ensure that we meet and exceed service and calibration standards such as:

  • ISO 21501-4:2007

ISO 9001:2008

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Recorded Webinar

ISO 14644-1/2: 2015

ISO 14644-1:2015 Revisions Summary

PRESENTER Daniele Pandolfi Global Product Specialist Aerosol, Life Science Division

Watch this on-demand webinar and learn about ISO 14644-1:2015 and how it affects your clean anvironment monitoring

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Recorded Webinar

Personnel pose the greatest risk of false positives in aseptic processing. The BioCapt® Single-Use eliminates false positives and costly investigations by preventing direct operator contact with the media plate.

Watch Now

Ask a Question

ISO 14644-1/2: 2015

Do you have an ISO 14644-1 question? Read our frequently asked questions below or submit your specific question and one of our experts will respond shortly. 

Frequently Asked Questions

Aerosol Particle Counter?

Can the Lasair II 550L be upgraded to be compliant with ISO 21501-4?

The Lasair II 550L cannot be upgraded to the new ISO certification requirements. This product has been obsolete since 2009 and it is recommended to upgrade to the fully compliant Lasair III. We can provide a quotation if you are interested in a new unit.


How does the recent Lasair III firmware update work with the EU GMP classification for Grade A areas with the corrected ISO standard?

EU GMP Annex 1 provides specific particle concentration limits for specific cleanroom classes (Grade A, B, C and D). The Lasair III Aerosol Particle Counter, when used with GMP statistical mode, will refer to the GMP maximum concentration table.

To view all FAQs on this subject download the ISO14644-2 FAQ


Does ISO 14644-1 apply to a solid dose facility?

Yes, ISO 14644-1 can be applied to this type of manufacturing area. You should verify which class and standard your cleanroom must be compliant with. ISO 14644-1 is applicable for any type of cleanroom, including Pharmaceuticals.


Has the new ISO had an effect on the number of the stationary particle counters (for monitoring) in a filling machine?

No, the number of continuous sample locations is not affected by the ISO14644-1. Monitoring control guidelines are available in the ISO14644-2 standards which clearly require a risk assessment based approach for the evaluation/selection of the sample location. Use this document for suggestions in selecting the best non-viable location for monitoring purposes.

To view all FAQs on this subject download the ISO14644-2 FAQ

Can I omit the annual cleanroom classification required by the ISO 14644-1 if I run a continuous monitoring?

No, the cleanroom monitoring cannot replace the classification test to be performed on annual or semi-annual base.

Also, the classification process dictated by the iso14644-1 must be performed in combination with the equipment/Hvac system test as per ISO14644-3.

Which particle sizes should I monitor in my cleanroom?

The particle size must be determined according with your process and product requirements.

Generally, Pharmaceutical producer are required to monitor particles # 0.5 and 5 micron.

The ISO14644-1 removed the needs of classify the class 5 for 5um particles, what about the monitoring?

In Pharmaceutical industries, 5um particles are still required to be monitored in ISO class 5.

A risk assessment analysis is required to support the selection of specific particle sizes to be monitored.

Is the ISO 14644-2 also considering the microbial monitoring?

ISO 14644 do not specifically talk about microbial contamination, but takes only care of particles. Anyway, microbial contamination must be controlled as well during production using appropriate monitoring tools. You can find additional details in the EU-GMP Annex 1, FDA cGMP and ISO 14698.

What is the right sample height?

The sample height, or sample location, must be within 1 foot from the critical zone. The sample height must always be in proximity or equal to the work height.

Particle sample shall never be done just under the filter, unless during filter scanning test.

Which parameters, other than particles, should be monitored in the cleanrooms?

Several operating condition and performance should be monitored in cleanroom, again based on your specific process and product risk evaluation. The ISO list, but not limits to, parameters like temperatures, differential pressure, humidity, ventilation performance ….

Does the CFR 21 part 11 applies to the ISO monitoring requirements?

CFR 21 part 11 dictate the requirement for the correct management of data. As part of batch release process, the data collected by any monitoring systems, shall be managed with appropriate software system or procedure in respect of the Data Integrity good practices and CFR 21 part 11 standard.

How many samples should I take to develop my alarm limits?

It’s recommended to define alert and action limit based on a consistent amount of data, typically 4 to 6 months trend provides a consistent and reliable picture to be used for limit set-up.

Which particles value should I get from my instrument? Cumulative or differential?

All standards, including ISO, GMP etc, always refer to cumulative particle.

Differential value can be used for investigation and troubleshooting purpose.

Can I use stainless steel tubing to connect the particle counter to remote sample location?

Yes, stainless steel 316L tubing can be used, as well as other material such as Tygon, Bev-a-line or Polyurethane.

It is important to select the tubing based on the adherence characteristics and strictly respecting the specific internal diameter size as specified by the manufacturer.

Where can we find the difference between the new ISO 21501-4 standard for calibration of p-counters and older ISO stds for calibration of such instruments?

Unfortunately there are no answer to this question, because prior the ISO 21501-4 (2007), no ISO standard where existing for particle counter calibration and any instrument manufacturer were using his own procedure and method… limiting the harmonization and repeatability of measurements.

Is the allowed distance from the critical point to the particle counter valid for all type of particle counter or just for 1 ft³ Counter?

The instrument manufacturer must specify in the user manual or specification sheet which is the maximum allowed tubing length. In most case this is equal among different flowrate.

If the Grade A area is in operation for 2 hours would you monitor that area continuously and then the surrounding Grade B immediately after operation, to cover the 'daily' requirement?

Your proposed approach is right. The grade B may be even be sampled prior the filling to verify the cleanliness of the area and suitability for the production operation.

What is the recommendation for monitoring sampling approach - collecting 1 full cubic meter, or a series of 1-minute samples?

In a monitoring scenario, I would recommend you to configure your particle counter to a series of 1-min samples. This method will provide you a better “real time” vision of any unexpected event.

What if you are a startup process and don't have any historical data to use to set your alert and action limits?

You can start referring to the ISO 14644-1 Classification limits for your specific cleanliness class, and begin create your data trend as soon as possible.

Does the monitoring sample location relate to the classification sampling plan in 14644-1 (i.e. same sample positions) or is it entirely different?

No, you do not need to replicate the same sample location classified as per ISO 14644-1.

Most of the time the number of position per monitoring are less than half of the classification requirement.

The selection of monitoring sample location must be supported by a risk assessment.

How often is it necessary to verify and calibrate the particle counters?

ISO 14644 refer to the ISO 21501-4 for calibration requirement. This standard recommend the calibration to be done at least once per year or less.

Should the fan/motor system in a clean filtered laminar flow cabinet be turned on for a time well before the cabinet is used to dispense pharmaceuticals?

Yes, this is a normal practices to ensure the flow cabinet is in the right cleanliness condition before starting the production process.

I also suggest you to evaluate the recovery time following the ISO14644-3 standard, in this way you can define how many minutes/hours you need to run the fan prior the production activities.

To your knowledge, have the EU-GMP guidelines accepted the 2015 edition in the same way in which they accepted the prior version?

Absolutely yes. GMP guidelines refer to the ISO 14644 in many section, but without any specific revision number or release date. This always mean that the latest/actual version must be applied.

Anytime you read a GMP reference to the ISO standard, you need to consider the last version available (for this case, the 2015).

In your opinion would it be acceptable to verify the performance of a built-in particle counter (in an ISO-5 isolator hood) with a hand-held, calibrated particle counter rather than remove the built-in particle counter and send away for calibration?

Unfortunately no, this kind of test will not provide any evidences of:

  • Counting efficiency
  • Size error
  • Resolution
  • Flow rate verification
  • Etc etc…..

All particle counter must be calibrated and “challenged” against a calibrated reference instrument (not an handheld device) in order to comply with the ISO 21501-4 standard

How many locations should I control in a cleanroom?

For classification process, you can define the number of sample location by referring to the table A.1 available in the ISO 14644-1:2015.

In case of monitoring, you need to develop an appropriate risk assessment in order to identify your critical location to be sampled.