3M™ Fire Barrier Rated Foam FIP 1-Step is a two-part urethane, smoke, sound and firestopping foam. This intumescent foam is engineered to expand in the event of a fire. It is firestop tested up to 2 hours in accordance with ASTM E 814 (UL 1479) and CAN/ULC S115. When dispensed, this foam cures quickly, reaching full expansion after approximately 2 minutes and expanding up to 5 times its size. This product foams in place without sagging or running and is designed to fill the void between the through penetrant (pipe, cable, etc.) and the wall, creating a firestop seal and restoring the fire rating of the entire wall. We formulated this foam to be re-enterable and repairable, remaining pliable after installation for the easy installation of new cables/conduit in existing openings.