Amine system particle filtration is an accepted part of gas plant and refinery sour gas sweetening and plays a key role in maintaining operational efficiency by preventing fouling of the system hardware, reducing incidences of particle stabilized foaming, and promoting a clean gas-liquid interface. While much has been written about target removal efficiencies and the pros and cons of depth versus surface filtration and absolute versus nominal filters, scarce attention has been paid to one of the most important features of any filter at all, and the first question the amine system operator should ask – What is the filter made out of? Polypropylene and cellulose, the latter in the form of pleated paper or cotton string, are the predominant players in the industry, and the two are as different as night and day. The oil-wetting properties of polypropylene enhance its particle removal capability in hydrocarbon-infused amine beyond its stated micron rating, enabling it to capture particles far smaller than its pore structure would suggest, keeping the circulating fluid clean while better resisting plugging which prolongs filter life. Cellulose, on the other hand, degrades in amine, setting the stage for oxygen sepsis and the generation of heat stable salts. The paper will present data showing that open grade (40 micron absolute) meltblown polypropylene microfiber media can reduce incoming amine total suspended solids by over an order of magnitude. Additionally, data will be provided that indicates cellulose-based media contributes to the formation of oxygen-derived heat stable salts, including those of formate, sulfate, and oxalate.