Qualitative Filter Paper - 6010-4000 - Grade 601, 40cmAhlstrom Munksj 601 2. 5 m, Medium Speed This grade covers a wide range of laboratory applications and is used for clarifying liquids and for rapid filtration of coarser precipitates such as lead sulfate, lead chromate, calcium oxalate, calcium carbonate, aluminum phosphate, barium carbonate, and beryllium hydroxide. Grade 601 can be found in soil analysis, seed testing, and in air pollution to collect dust laden air and is also commonly used in the