Seals The Wood Protects Against Mold And Mildew Kills Off Harmful Insects Dip soaking or pressure impregnation of COPPER-GREEN will result in deeper penetration resulting in longer preservation of treatable species The copper in COPPER-GREEN reacts with the cellulose of wood. As a result it is not easily lost from the wood by leaching This formulation extends the service life of wood products For exterior applications only