It is compatible over a wide variety of conventional solvent based and water based urethane and epoxy coatings (provided that these coatings are cured, bonded and the floor is properly prepared. Not compatible over acrylic floor finishes). No catalyst is required (this product cures via oxidation - like conventional oil-modified urethanes) to produce a finish that provides exceptional durability and scuff resistance. Manufacturer's Recommendation: This coating is to be applied without thinning. VOC Content = 180 grams/liter, excluding water