Heat tolerance

To all, I bought a piece of taffeta on eBay. Beautiful fabric. But they didn't and I don't know if it is silk or polyester. But to assume the worst with what I want to do with it...Will polyester tolerate the heat of a fusible knit interfacing? Or will it damage it in any way? Yes I know, test it but I can't buy a 4" square of interfacing and I don't keep quantities on hand. Not that I would be able to locate any scraps right now if I had kept any. Which reminds me of what I should be doing, cleaning up the massive clutter that passes for my sewing area. AK in PA