The Firefoam B2 Gungrade is a quick setting fire rated, one part polyurethane foam for application by a foam applicator gun, this foam is fire resistant for up to 2 hours in certain joint configurations. The foam from Everbuild expands up to x 50 the cans original contents, & meets the requirements of the test criteria for BS476 Part 20, also this foam adheres to plastic, stone, brick, concrete, metals, timber etc & is for professional use only.