OSI Fire Block Foam provides an effective barrier designed to inhibit the passage of fire, smoke, and toxic gases through service penetrations and other openings inside concealed space of Type V-A construction projects, occupancy group R3 and R5 (wood frame) buildings. This high-performance, single-component fire block foam sets in 10 minutes and cures upon reaction with moisture to form a flexible, low-pressure polyurethane foam. Developed for gaps that surround mechanical ductwork, plumbing, wiring, ventilation, and pipes, OSI Fire Block Foam adheres to most types of building materials including wood, concrete, brick, metals, cable jacketing; and will not harm PVC, CPVC and PEX pipe/tubing. It complies with all Federal and State VOC regulations.