The presentation focuses on the methodology developed by Syensqo to test compatibility of plastic materials to a fuel cell environment. The method, which leverages the use of a real fuel cell to determine the impact of contaminants, allows not only to compare qualitatively different products, but also provides quantitative estimates of the membrane poisoning and informs about the consequent reduction in power generated. In addition, the correlation between this quantitative value and the corresponding ion content and type has been investigated. The method sets the basis for a more accurate material selection, which goes beyond simple conductivity measurement that is today considered standard practice in the industry.