Yes and no! Some paints contain styrene or isocyanates, which are as unpleasant as they sound and potentially harmful to fish. Others contain biocides (in-can preservatives to increase the shelf life of the paint) which will leach out of the paint into the pond water. RESIENT Pondsafe contains no styrene, no isocyanates and no in-can biocides. It has been specifically formulated for the sole purpose of being a safe pond paint, unlike many other products which are simply re-badged water based epoxy or acrylic paints.