Fire Protection is Just the BeginningDesigned as a smooth, easy and convenient alternative to conventional firestop packing materials such as mineral wool, fiberglass and backer rod, 3M Fire Barrier Packing Material PM4 is much more than just another non-combustible filler. Its smooth, strong and flexible, and its woven construction is less irritating to the skin when compared to conventional mineral wool commonly used in firestop applications. In addition, it is packaged so users can easily transport it to any job location and carry it directly to the application site. It is equally easy to dispense installers simply pull out a length of smooth woven PM4 material from its package and tear it off by hand without the need for knives or other tools.Recommended ApplicationsMetallic, nonmetallic, insulated pipe penetrationsHVAC and power penetrantsCommunication cable penetrantsCommercial and industrial constructionFully Tested and ApprovedApproved for use in all UL-listed through penetration 3M firestop systems, our 3M Fire Barrier Packing Material PM4 is an inorganic, non-asbestos material ideal for filling around fire protection installations. This inorganic, non-asbestos material is non-combustible per ASTM E 136 testing. It also meets the ASTM C 1338 for resistance to mold and other fungi, helping to ensure permanent firestop installation.The Science of Better Fire Protection from 3MSince 1925 when a lab assistant invented masking tape, 3M has been applying science to life developing adhesive products and technologies that help entire industries and individual businesses worldwide. The work that began with a single 3M engineer now spans decades and generations. And all of it goes into each 3M adhesive, sealant and protective coating including 3M Fire Barrier Packing Material PM4 to improve performance, and to help businesses like yours operate faster, better and more efficiently.