Ahlstrom 111: 1.2µm - Fast Speed. This grade offers fine particle retention with high filtration speed and good loading capacity. Used in general laboratory filtration including atmospheric and water pollution monitoring such as intake controls, ozone-level, and water effluents. Grade 111 is also well suited for filtration of water and protein, testing of algae, bacteria cultures and for radioimmunoassay with weak beta emitters. Also recommended for filtering solvents in a high-resolution laboratory.