This standard grade found in many environmental applications offers slightly more retention than Ahlstrom 111 with slightly lower filtration speed and loading capacity. Ahlstrom 131 is recommended for the collection of suspended solids in potable water and in industrial wastes. In biochemical tests, Ahlstrom 131 is suited for cell harvesting, liquid scintillation counting and the analysis of carbohydrates.

Standard glass microfiber filters contain no binders or other additives that may cause interference to sensitive enzymatic or other chemical reactions. The unique characteristics of glass microfiber filters make its use particularly advantageous to laboratory filtration by enabling fast filtration of large volumes and difficult solutions without premature clogging.