Cure & Seal 30% J23WB is designed to be used on freshly finished concrete as an earth friendly membrane forming curing compound that surpasses the requirements of ASTM C-309 and C-1315. Cure & Seal 30% J23WB can be used on both interior and exterior concrete surfaces. This ultra low VOC curing and sealing compound can be used in all VOC restricted regions throughout the United States.