I can't say if Isopropyl can or won't damage the emulsion on photographic film, but I don't use it because of the residue that it can leave behind. I can only speak for the Isopropyl's that I've tested. To test, place a drop of the Isopropyl on a piece of clean glass. Once it has dried, examine the glass with a loupe. You "may" find that the Isopropyl has left behind a residue on the glass. If present, you may decide that you don't want this residue on your film.