OSI® FIRE BLOCK
![Product Image](/wp-content/uploads/2025/01/OSI-Fire-Block.jpg)
OSI® Fire Block Foam provides critical extra protection against the spread of smoke through holes and other building penetrations. Designed with a closed-cell polyurethane structure, it delivers critical blocking capabilities without cracking or drying out over time. Approved for use in Type V-A and occupancy group R3 and R5 buildings.