Fire Protection

NmES3M Fire Protection Products

tic Installation FeaturesStopping Procedures

T he telecommunications cable plantinstalled in the South Coasr AirQuality Management District

(SCAQMD) headquarters has beenprotected with approved firestop materialsand procedureb wherever cables penetrateraed firewalls. Th¡!, firestopping effortincluded use of new materials andprocedures required to satisfy the specialneeds of fiber optic cabling and protectiveinner duct and achieve the required two-hour firestop rating.

As the air pollution control agency forthe four-county region that incorporatesLos Angeles, Orange, and RiversideCounties, and portionr, of San BernadinoCounty, this district air qualitymanagement office i s the nation’s largestlocal authority for administeringenvironmental rcoulations. TheSCAQMD ch&requires administrationof some 45,000 smogpermit files containingmore than a millionpages of information.

The six-storySCAQMD building israed Class IA for fueprotection because itincorporates alaboratory withpotentially explosive o*hazardous ga\es. Firecodes require that allpenetrations of tire-rated walls and floorsin the building befirestopped withapproved materials andmethods to prevent

propagation of fire or spread of toxicfumes in the event of a fire.

It is important that firewall openings besealed against both heat and pressure,even when penetrated by meltable cablejackets and plartic fiber optic inner duct.Tests show that temperatures in âstructural fire can quickly exceed I IOOC,and smoke and toxic gases are released inlarge quantities. When such a tire isconfined to a small area. pressures alsorise quickly, causing jets of smoke, flameand toxic fumes to be forced outwardthrough the smallest firewall openings.Without firestopping, even û small firecan propagate quickly through a buildingresulting in majar property damage andpotential harm to people.

The SCAQMD headquarters contains 22telecommunications closets, each fed with

copper and fiber optic cable, to serve bothdata and voice. A two-hour fire rating hadto be achieved for 50 different wallpenetration points, with protection on bothsides of the walls - and 36 floor locations,requiring firestopping above and below.

Firewall and floor penetrations in eachcloset were sealed using one or two

provides fimstoppmgintegrity in largefirewa1l openings.

upon the size of theopening. For small openings in gypsumwalls that involve cable bundles orindividual conduits, a non-hardeningmaterial called 3M Fire Barrier MoldablePutty+ was used to filI the opening aroundthe cable or cables. This permanently softfirestop material allows changes in thecable plant with minimal effort, andfirestop protection is restored quickly afterwiring changes are completed by replacingthe putty.

For larger firewall openings that could notbe firestopped using putty alone, 3M FireBarrier CS195+ Composite Sheet,consisting of a fire resistant material

bonded to 28 ga. steel and reinforced withwire mesh and aluminum foil was used.The circumferences of cable and conduitpassing through this composite barrier arealso sealed - either with 3M Fire BarrierMoldable Putty or a 3M Fire BarrierCP-ZWB+ Caulk.

Special3M materials and processes forfirestopping fiber optic inner duct wereused in the SCAQMD installation.Materials that melt or burn away, such asPVC inner duct, create a void in thefirewall that must be filled as a fireprogresses. The 3M fiber optic cablefirestopping method eliminates the need toterminate the inner duct at the penetrationpoint so that continuous cable protection i sassured.

This problem was solved with the use of aproduct called 3M Fire Barrier FS-195+Wrap/Strip, along with Moldable Putty. Alayer of this flexible strip was placedaround the inner duct, inside thepenetration, such as inside a concrete flooropening. Then the outer surface was filledand sealed, both above and below, withMoldable Putty. This firestopping methodeliminates the need to terminate the innerduct at the point of firewall or floorpenetration, and reduces risk of damage tothe cable with continuous protection fromfue, smoke and fumes.

While the plastic inner duct used for thisinstallation is fire and riser rated, themanufacturer had not included the requiredconfiiation stamp on the outer surface.Consequently, local building inspectorsrequired that inner duct inside Ere ratedspaces in the SCAQMD building bewrapped with 3M Scotch brand 77 tape asa further fire protection measure. 3Mproducts for inner duct firestopping are ULClassified and FM approved, and havebeen tested according to ASTM E 8 14 .

Fire Pmtection Products3M Center, Building 207.1%02St. Paul, MN 55144-113W8 0 0 3 2 8 1 6 8 7