Displays arylsulfatase activity at acidic pH towards artificial substrates, such as p-nitrocatechol sulfate and also, but with a lower activity towards p-nitrophenyl sulfate and 4- methylumbelliferyl sulfate (PubMed:18283100, PubMed:29300381). Catalyzes the hydrolysis of the 3-sulfate groups of the N-sulfo-D- glucosamine 3-O-sulfate units of heparin (PubMed:22689975). {ECO:0000269|PubMed:18283100, ECO:0000269|PubMed:22689975, ECO:0000269|PubMed:29300381}. This is the function of ENSG00000141337 (ARSG, arylsulfatase G).