Pyrobar was a United States Gypsum Company (USG) trade name applied to a family of hollow gypsum-and-cement structural tiles engineered for use in fire-rated floor, roof, and partition assemblies in commercial, institutional, and industrial buildings. Plaintiffs have alleged in publicly filed U.S. asbestos personal-injury and wrongful-death litigation that certain Pyrobar formulations incorporated chrysotile asbestos fiber into the tile matrix, and that workers who cut, drilled, and chipped these tiles during installation and demolition were exposed to respirable asbestos fibers.

Product Description

Pyrobar tile was allegedly manufactured by USG as a lightweight, non-combustible structural tile intended primarily for reinforced-concrete floor systems and fire-rated roof decks. In floor construction, Pyrobar tiles were laid in rows over temporary formwork with concrete poured over and between the tiles to form a monolithic ribbed slab; the tiles remained in place as permanent fill and delivered the required fire rating.

The Pyrobar product line allegedly included:

  • Hollow-core floor tile for reinforced-concrete floor systems
  • Roof tile for fire-rated flat and low-slope roof decks
  • Partition tile for fire-rated interior walls
  • Column and beam fireproofing tile
  • Mortar mix and setting compounds sold as companion products

Pyrobar was specified in schools, hospitals, government buildings, factories, and mid-rise commercial buildings throughout the twentieth century. Some Pyrobar formulations allegedly incorporated chrysotile asbestos fiber as part of the cementitious binder system to improve fire resistance and mechanical strength.

Workers Exposed

Plaintiffs have alleged in publicly filed U.S. asbestos personal-injury and wrongful-death litigation that the following trades encountered respirable asbestos dust from Pyrobar fireproof tile:

  • Bricklayers and masons who set Pyrobar tile in floor and roof deck assemblies, cutting units to fit at slab edges, columns, and penetrations using masonry saws and hand chisels.
  • Tile setters and construction laborers who handled, positioned, and cut tile on active construction sites, generating dust during scoring and snapping operations.
  • Concrete finishers who worked on Pyrobar-filled slabs, cutting and drilling through tile-and-concrete assemblies for embedded conduit, drains, and floor boxes.
  • Trade contractors on renovation projects — including electricians, plumbers, and mechanical trades — who cored and chipped through Pyrobar floor and roof assemblies to install new services in existing buildings.
  • Demolition workers and abatement contractors who removed Pyrobar floor and roof assemblies during major renovations and building demolitions, fracturing decades-old tile and releasing airborne fiber during breakage and haul-out.
  • Building maintenance mechanics who chipped and patched Pyrobar assemblies during routine service work in schools, hospitals, and institutional buildings.

Plaintiffs have alleged that cutting Pyrobar tile with dry masonry saws generated substantial dust and that renovation and demolition work on aged Pyrobar assemblies was a particularly high-exposure activity because the material had weathered and become friable.