€¢ Treats all general firestopping applications for combustible & non-combustible penetrations €¢ 4 hour system tested €¢ Intumescent product expansion fills the void created by combustible materials burned during a fire €¢ Red color for easy inspection €¢ Interior use >> Single component; water-based intumescent acrylic firestop sealant. Blockade meets ASTM E 814/UL 1479 specification for fire tests of penetration firestops. Intumescent product expansion fills the void created by combustible materials burned during a fire."