3M™ Fire Barrier Sealant CP 25WB+ is a high-performance latex-based intumescent firestop sealant. When properly installed, this product provides up to 4 hours of fire protection in tested and listed systems. When properly installed, the 3M™ Fire Barrier Sealant helps prevent the spread of fire, smoke and noxious gas. In addition, this product acts as an acoustic barrier by minimizing noise transfer (STC-Rating of 54 when tested in a STC 54-rated wall assembly), helps create a smoke seal for systems requiring the optional L-Rating, meets the intent of LEED® green building program credits VOC environmental regulations and International Building Code (IBC) requirements.