The higher the speed, the shorter the useful shelf life of frozen film: Kodachrome 25 Professional, exp. 10/1993, virtually unaffected; Kodachrome 200 Professional, exp. 11/1992, fogged with very reduced maximum density; Fujichrome RFP 50, exp. 05/1991, still usable, but quite cool; Ektachrome 400, exp. 08/1992, blue D-max, pale, washed-out colors - I would recommend to store 400 ASA slide film at most for five years after expiration, 100 ASA film for 10 years, and to finish all Kodachrome, irrespective of speed, before the end of 2010