Understanding airborne particle counters in pharmaceutical facilities

Published: 17-Jan-2024

Airborne particle counters play a crucial role in ensuring the environmental integrity of pharmaceutical, bio-pharmaceutical, and radiopharmaceutical facilities worldwide

In an increasingly globalised pharmaceutical industry, cooperation and harmonisation have become the norm, driving the demand for continuous monitoring in these facilities as well as the drive for digital solutions to meet your Contamination Control Strategy. In this article, we’ll explore the significance of airborne particle counters, their types, and their vital role in maintaining cleanroom environments.

Types of Airborne Particle Counters

There are three primary types of Airborne Particle Counters (APCs): handheld, portable and fixed point remote. We will focus on Portable APCs and Fixed Point APCs.

Portable APCs

Portable APCs are self-contained instruments equipped with user-friendly interfaces for control. They come with built-in sampling systems, making them easy to transport. Users can establish sample parameters, collect data, and, if necessary, transmit data to external systems digitally over WiFi or a secure network. To prevent contamination, the air sampling system must have an exhaust system with effective HEPA filtration.

Portable APCs can operate on internal batteries or AC wall outlets, and they vary in sample flow rates:

28.3L/min – Standard Flow Portable APC: Features a sample flow rate of 1.0 CFM (28.3 LPM), commonly used in general cleanroom operations.

100L/min High Flow Portable APC: Equipped with sample flow rates exceeding 1.0 CFM (28.3 LPM), making them valuable in cleanroom certification testing, for example Higher flow rate such as 100L/min instruments are especially useful in Grade A environments, as they significantly reduce sampling time significantly when sampling larger particle sizes above 3um.

Fixed-Point Remote APCs

Fixed-point remote APCs are smaller, less intrusive, and more robust compared to their portable counterparts. They can be attached to process equipment, cleanroom walls, or transport devices. These APCs typically operate with sample flow rates of either 0.1 CFM (2.83 LPM) or 1.0 CFM (28.3 LPM). They are designed for data logging or transmitting data in real time to external systems such as Building Management Systems (BMS), Non-Viable Particle Monitoring Systems (NVPMS), or Facility Monitoring Systems (FMS).

Fixed-point remote APCs can be further categorised into two types: those with built-in pumps and those without built-in pumps.

Remote APCs with Built-In Pumps: These units have built-in sample handling systems and filtration for exhaust air. While they are larger, can be noisier, and more expensive than those without pumps, they eliminate the need for a facility-wide vacuum pump and distribution system. However, they require regular filter replacement and pump maintenance.

Remote APCs without Pumps: These APCs rely on an external vacuum source, making them smaller, quieter, and more cost-effective. They have lower service costs as there are no internal filters or small pumps to maintain. However, the facility-wide vacuum system must be regularly serviced to ensure proper flow and it is advisable to have a redundant vacuum system in place for business continuity.

Cleanroom Classification vs. Process Monitoring

Understanding the distinction between cleanroom classification and process monitoring is crucial when configuring and using particle counters in pharmaceutical facilities.

Cleanroom Classification: Cleanroom classification, often known as cleanroom validation or cleanroom certification, involves formal testing of the environment according to ISO 14644-1 criteria. It includes selecting sample locations, defining sample volumes, and meeting additional certification requirements such as monitoring both 0.5 and 5.0 micron particle sizes. Cleanroom classification provides confidence that the air quality complies with maximum particle concentration limits for a specific class of air cleanliness. It basically Verifies that the cleanrooms performance meets the cleanroom standard it was designed for.

Operational Process Environmental Monitoring: This is an ongoing monitoring process that continuously tracks critical locations within high-risk operations where aseptic products are manufactured. It includes alarming and notification systems to alert personnel about conditions approaching operational limits or exceeding them in real time. This data can be part of batch release information.

Critical areas that require continuous monitoring typically involve exposure to sterilised drug products, containers, and enclosures vulnerable to contamination. These high-risk operations occur under Grade A conditions, often associated with uni-directional airflow environments. This type of Monitoring basically validates that the cleanroom is operating within control limits.

Understanding airborne particle counters in pharmaceutical facilities

Particle Counter Fundamental Requirements

Particle counters used for monitoring in pharmaceutical facilities must meet specific design, reliability, durability, and calibration standards:

Suitable Design: Particle counters should be designed not to influence the environment they monitor. They should withstand cleaning and decontamination processes and be chemically compatible with cleaning agents. Particle Counters should be ergonomic and lightweight and easy to carry. Long battery operation is also a good feature to ensure business continuity.

Reliability and Durability: Particle counters should be constructed to ensure durability, especially considering the finite lifespan of laser diodes, a common component in these devices.

Performance and Calibration: Particle counters must be calibrated according to ISO 21501-4 standards, including calibration of particle sizes, flow rate, size resolution, counting efficiency, false count rate, and voltage limits.

Particle Counters should also validate the particle count data and be designed to insure data integrity.

Country-Specific Requirements

Different countries may have their own recommended practices or requirements for airborne particle counters. For example, Japan has JIS B 9921, while China has JJF 1190-2008, both outlining specific calibration specifications. The United States offers ASTM F50-129 and IEST-RP-CC0148, and the UK provides PHSS Technical Monograph Number 16 as guidance. However ISO 14644-1:2015  is a harmonized international standard that every particle counter should support.

Factors to Consider in Particle Counter Selection

Selecting the right particle monitoring system for a regulated environment requires careful consideration of various factors:

  • Product Type: The type of product being manufactured may impact equipment selection due to specific hazards or environmental conditions.
  • Sterilisation Method: Knowing whether the product is terminally sterilised or aseptically filled can help in designing the monitoring system.
  • Cleanroom Grades: Identifying the cleanroom grades to be monitored determines the number of monitoring points and operational limits to be considered.
  • Destination Country: Different countries may have varying regulations that affect system design.
  • Equipment Used: Understanding the manufacturing equipment used can pinpoint critical monitoring locations.
  • Type of Remote APC: Deciding between remote APCs with or without built-in pumps depends on facility constraints and placement considerations.
  • Monitoring Locations: Determine locations based on risk assessments and past monitoring data, avoiding reliance on ISO 14644-1 grid patterns.
  • Connectivity: Ethernet, WiFi or API
  • Data Export: CIFs, Network or WiFi enabled for digital data exporting.


Airborne particle counters are indispensable tools for pharmaceutical, bio-pharmaceutical, and radiopharmaceutical facilities worldwide. They play a critical role in maintaining the environmental integrity required for the production of safe and effective pharmaceutical products. Understanding the types of airborne particle counters, their roles in cleanroom classification and process monitoring, and the various considerations for their selection is essential for ensuring compliance with regulatory standards and product quality assurance.

Airborne Particle Counters

Our Airborne Particle Counters set the industry standard when it comes to detecting airborne pathogens. They are available in both indoor and outdoor models. We do highly recommend moving away from paper records to a paperless solution using the ApexZ.

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