October 30, 2023

Recent Non-Volatile Residue Standardization at ASTM


Although this title manages to capture three yawn-inducing groups of words[1] (“non-volatile residue,” “standardization”, and “ASTM”), when these groups are combined, they represent an important subject for manufacturers of medical devices. Non-volatile residues (NVR) are those residues that can be removed from a medical device that are not intended to be part of the device, and are of sufficiently low volatility that they do not evaporate upon removal of extraction solvent. NVRs are often used to assess how clean a device is, or how effective a manufacturing process is.

The American Society for Testing and Materials (ASTM), the United States Pharmacopeia (USP), and the International Standards Organization (ISO) employs the concept NVR in several of their standards. For example, in extraction and leaching studies of medical devices used for chemical risk assessment per ISO 10993-18 and USP, NVR measurements of components that can be extracted from finished medical devices are used to established both the total mass of extractable residue as well as an indication of whether exhaustive extraction conditions have been achieved.

NVR Standards for Medical Devices

Scientists at Cambridge Polymer Group are involved in drafting several new standards involving NVR assessment. In ASTM committee F42.07.03 for additive manufacturing of medical devices, a new standard is being developed to quantitatively measure residual powder bed feedstock on additive-manufactured medical devices, with one required test using NVR measurements. This draft standard is currently titled Standard Test Method for Additive Manufacturing for Medical – Powder Bed Fusion – Assessment of Residual Powder (WK82776).

Another standard that involves NVR measurements is ASTM F2459 Standard Test Method for Extracting Residue from Metallic Medical Components and Quantifying via Gravimetric Analysis, which is primarily used as a measurement of how clean medical devices are. This standard, which originated at Cambridge Polymer Group, is currently being modified to include plastic and ceramic medical devices.

At Cambridge Polymer Group, we are regularly involved with measuring NVR in medical devices to help ensure safety and compliance to standards. Contact us to have us help you with your NVR measurements.

[1] To some. To Cambridge Polymer Group, they each are a riveting subject.