Biostop Intumescent Sleeve
is a firestop seal for PVC, cc-PVC, CPVC, FRPP, PP and ABS pipe and rigid non-metallic conduit installations. Easily installed without modifications, steel bolts or fasteners, the Intumescent Sleeve is an ideal approach for firestopping combustible pipes penetrating the uneven contours of a concrete fluted deck assembly.
US Patent No. 6,207,085.