fischer FiAM US is a one part, general purpose fire rated sealant and smoke seal for construction joints and through penetrations. fischer FiAM US is a water based, caulking grade sealant that is easy to apply as well as to retrofit. It cures to an elastomeric seal that is suitable where dynamic movement is expected. Tested extensively to UL 1479 (ASTM E814) and UL 2079 (ASTM E1966) it is tailored for market places in which UL listed applications are required