ASTM E3508-25

1.1 Information on the counts and types of particulate matter present on the surfaces of single-use bioprocessing equipment (single-use systems, SUS) is useful in the assessment of risks from particulate matter in the chosen bioprocess application of a SUS.

1.2 In this practice, a framework for reporting the particle count for both the subvisible (<100 µm) and visible (=100 µm) size ranges commonly applied to particulate matter is provided. In addition, in this practice, a framework is provided for classifying and reporting the chemical identities and likely source classifications (intrinsic/extrinsic) of the types of visible particulate matter (=100 µm) present on the interior (fluid-contacting) surfaces of a SUS.

1.3 This practice is applicable to the reporting of particulate matter data from SUS suppliers to end users (biopharmaceutical manufacturers) for the purpose of aiding in the determination of whether a SUS is fit for the purpose for the chosen bioprocess application.

1.4 This practice is applicable to the reporting of data on particulate matter present in SUS for quality control or process control purposes.

1.5 Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

4.1 Any risks to final drug product purity from particulate matter on the surfaces of single-use bioprocessing equipment (single-use systems (SUS)) depend on if the SUS is implemented upstream or downstream of sterilizing grade filters or in aseptic processes (see “Recommendations for the Testing, Evaluation, and Control of Particulates from Single-Use Process Equipment” for guidance).4 Regardless of the risk scenario associated with a specific SUS process application, information on the counts and types of particulate matter present on the interior surfaces of a SUS is useful in the assessment of whether a SUS is fit for purpose in the chosen bioprocess application.

4.2 Although usually manufactured in cleanrooms, some particulate matter may adhere to the interior (often fluid-contacting) or exterior surfaces of single-use bioprocess equipment (SUS). The detectability of particulate matter in a visual inspection of SUS is often limited by the complexity, size, and translucent or opaque components that inhibit visualization of the interior surfaces. A more complete assessment of the levels and types of particulate matter present on the interior (fluid-contacting) surfaces of SUS requires liquid extraction of the particulate matter followed by procedures that determine the count, size, and type of the particulate matter present in the extraction liquid. See Guide E3466 and Practice E3468 for guidance on the development and requirements for validation of particle quantification test methods for SUS.

4.3 In this practice, a framework for exchanging data on particle count, size, and chemical identity between SUS suppliers and end users (biopharmaceutical manufacturers) is provided. In this practice, reporting the exact sources of particulate matter is not addressed nor is the level of information required to determine toxicity risks from particulate matter potentially present in a final drug product provided.

4.4 Note that particulate matter may be generated by process specific stresses (for example, pumping or mixing); however, reporting such particulate matter is out of the scope of this practice.