Polyureas are made with ashless organic thickeners and have a good resistance to oxidation. They provide very good high temperature performance since the consistency will not drop that much at elevated temperatures. This makes the grease very suitable where potential leakage from the bearings is seen due to high temperature thinning of the grease. Polyurea greases are very suitable for long line centralized systems. Therefore polyurea greases are popular greases in steel and paper processes.