Duro-Nox is a chemically reactive, water-based sealer that penetrates the pores of concrete surfaces. It produces calcium silicate gels, which harden, densify, and seal the concrete to resist abrasion, impact damage, and stains. The product is 100% inorganic, nontoxic, and contains no VOCs, making it a good choice for use on "green" projects. www.nox-crete.com