Fire Rated Graphite is a high specification mastic designed to prevent the spread of fire, smoke and gases through openings in fire rated walls and floors. The mastic material expands when exposed to fire. It effectively seals openings around penetrations once any combustible or low-temperature melting materials have burned away. It also seals difficult services which traditional fire rated mastics do not achieve, including large plastic pipes. Fire Rated Graphite can be used with a suitable filling material in order to ensure the correct width to depth ratio to reduce the shrinking of the sealant during curing. Thermal activation takes place at 150 degrees when the material will expand to prevent the passage of fire and smoke for periods up to 4 hours.