Fiberlock AfterShock is an EPA-registered antimicrobial coating designed to kill residual mold and mildew remaining after pre-cleaning contaminated surfaces. AfterShock also inhibits the future growth and spread of mold and mildew on the cured coating film in residential and institutional buildings. This extremely durable, easy to apply, 100% acrylic sealant provides excellent fungicidal characteristics to address mold growth from water damage. AfterShock is recommended for use on interior wall surfaces such as plaster, wallboard, drywall, concrete, masonry block, wood, primed metal and galvanized metal. Not for use in HVAC systems.