Regulators enforce ISO 18562

by Andrew Blakinger, Manager, Extractables & Leachables Testing, Eurofins Medical Device Testing

All medical devices must be assessed for biocompatibility. Medical devices containing breathing gas pathways (e.g., ventilators, breathing tubes, and anesthesia equipment) have traditionally been evaluated as external communicating devices according to the ISO 10993 series of international standards. Unfortunately, this approach leads to testing that provides questionable benefits and may result in hazards being missed. Therefore, a new set of standards – ISO 18562 – was released in March 2017 and is now starting to be enforced by regulators. This four-part series is specifically geared towards the biocompatibility evaluation of breathing gas pathways in healthcare applications. ISO 18562-1 outlines the overall risk management process for the biocompatibility evaluation, while parts two through to four each address a specific type of hazard.

To support our clients, we now offer the full spectrum of testing required by the ISO 18562 series of standards to assess these three hazards. The first hazard is the emission of particulate matter. To evaluate this hazard, a particle counter is used to detect any particles of gas passing through the device.

ISO 18562-3 addresses the second hazard, that of volatile organic compounds (VOCs) emitted from the gas pathway. As air passes through the device, the VOCs are collected on a thermal desorption tube. These VOCs are then analysed by gas chromatography mass spectrometry (GC/MS) to identify and quantify them.

Leachables in condensate are the final hazard. During usage, water condenses inside the gas pathway. Compounds may then leach from the medical device into the condensate. Per ISO 18562-4, an aqueous extraction is first performed. Inductively coupled plasma optical emission spectroscopy (ICP-OES), direct injection GC/MS, and liquid chromatography mass spectrometry (LC/MS) are used to identify the leachables. Identification of these compounds is needed for a toxicologist to provide an accurate safety assessment. To identify the leachables, our scientists use the Eurofins Extractables Index, our proprietary database of over 1,500 compounds, in conjunction with the Wiley/NIST databases.

Complete understanding of the requirements of ISO-18562 – including regulatory expectations – is important in order to save valuable resources when working to get a medical device to market. Having successfully performed ISO 18562 for over a dozen medical devices, many of which have already received regulatory approval, the analytical scientists and toxicologists here at Eurofins Medical Device Testing are in a unique position to help medical device companies meet this testing requirement.