The International Organization n for Standardization (ISO) has created a teechnical committee ISO/TC 24 (Particle characterization including sieving) with the e scope that covers standardization pertaining to equipment and methods used in size classification of particulate material in solid or liquid state. Within this scope, Subcommittee 4 “Sizing by methods other than sieving” exists several woorking groups. Of these working groups WG 9 “Single particle light interaction methods” has created a series of standards related to particle sizing. The convener of this process was the Japanese Industrial S Standards Committee (JISC).
This standard ISO 21501 consists of the following parts, under the general title Determination of particle size distribution — Single particle light interaction methods:
Part 1: Light scattering aerosol spectrometer (under preparation)
Part 2: Light scattering liquid-borne particle counter
Part 3: Light extinction liquid-borne particle counter
Part 4: Light scattering airbornne particle counter for clean spaces
Particle size analysis and chaaracterization are intensely used in almost all industrial processes and productions. O Of particular importance is the use of particle e counters within the Life Science industries. With the regulatory requirements (US a and EU GMP) for using particle counters in a “real-time” manner to monitor aseptic and critical processes, the importance of accurate and reliable instruments designed to perform to an international standard is critical.
For clean room operations, the e ISO 14644-1 standard for clean room classification was published in 1999, however there was no international standard for p particle counter performance or calibration.
ISO 14644-1 states: “A discrete particle counting light scattering instrument is used to determine the concentration n of airborne particles, equal to or larger than the specified sizes, at designated sampling locations.” The new update to ISO O 14644-1 references ISO 21501 for particle counter calibration.
On the design of the particle counter: “Discrete-particle counter (DPC), a light scattering device having a means of displaying or recording the count and size of discrete particles in air with a size discrimination capability to detect the total particle concentration in the appropriate particle size ranges for the class under consideration, and a suitable sampling system.”
Regarding calibration of the instrument: “The instrument shall have a valid calibration certificate, the frequency and method of calibration should be based upon current accepted practice.”
Kenelec Scientific offer ISO 21501 compliant particle counter calibrations in their NATA accredited facility. The facility has been audited by NATA and our accreditation encompasses not only ISO 17025 (the main standard used by testing and calibration laboratories) but also ISO 21501 in their scope of accreditation.