Everbuild firefoam gungrade aerosol everbuild b2firehand firefoam b2 handheld is a quick setting fire rated one part polyurethane foam in a ready to use hand held canister fire resistant for up to 2 hours in certain joint configurations it expands on application to up to 50 times the can contents and meets the requirements of the test criteria for bs 476 part 20 everbuild b2firehand firefoam b2 hand grade aerosol 750ml