Fuel Cells will play an important role in reducing CO2 emissions from transport. As the LT-PEM technology has reached technical maturity, significant system cost reductions have to be achieved to reach customer acceptance without sacrificing durability and robustness. Contamination Control in the cooling loop and cathode air is essential to achieve this. In the presentation, we will show how cost-efficient solutions for Ion Exchange and Cathode Air Filters as well as for Gas-to-Gas Humidifiers are developed, based on in-depth knowledge of real-life contamination and material innovation, and how the application range can be extended beyond transport for further cost reduction.