Coelex 60 Unitab Brick

Product Description

The Coelex 60 Unitab Brick was a refractory product manufactured by Kaiser Gypsum during a four-year production window spanning 1974 through 1978. Refractory bricks of this type were engineered to withstand extreme heat conditions and were installed in high-temperature industrial environments such as furnaces, kilns, boilers, and other thermal processing equipment. The “Unitab” designation indicated a pre-formed, unitized construction that allowed for modular installation in refractory linings and thermal containment systems.

Kaiser Gypsum, a subsidiary of Kaiser Cement Corporation, operated as a significant manufacturer of construction and industrial materials throughout much of the twentieth century. The company’s product lines extended across gypsum wallboard, plasters, and specialty industrial materials, including refractory products such as the Coelex 60 Unitab Brick. Like many industrial manufacturers of the era, Kaiser Gypsum produced materials during a period when asbestos was widely incorporated into heat-resistant and fire-retardant products, often without adequate disclosure of the associated health hazards to workers or end users.

The Coelex 60 Unitab Brick was designed for durability under sustained thermal stress, making it a product that would be found in facilities where industrial workers operated heavy equipment and maintained high-temperature systems on a routine basis.

Asbestos Content

The Coelex 60 Unitab Brick contained chrysotile asbestos as a primary constituent material. Chrysotile, sometimes referred to as white asbestos, is a serpentine-form mineral fiber that was favored in refractory and thermal applications because of its resistance to heat, its tensile strength, and its ability to bind with other materials in composite manufacturing processes.

In refractory bricks, chrysotile fibers were incorporated to reinforce the structural integrity of the product under high-heat conditions and to help maintain the brick’s form when exposed to the thermal cycling common in industrial furnaces and kilns. Despite its widespread commercial use, chrysotile asbestos is classified as a known human carcinogen by the International Agency for Research on Cancer (IARC) and is regulated as a hazardous substance under federal frameworks including the Environmental Protection Agency’s Asbestos Hazard Emergency Response Act (AHERA) and OSHA’s asbestos exposure standards codified at 29 C.F.R. § 1910.1001 and 29 C.F.R. § 1926.1101.

There is no safe level of asbestos exposure established by federal health agencies, and chrysotile fibers—when inhaled—have been associated with mesothelioma, asbestosis, lung cancer, and other serious pulmonary diseases. The latency period for asbestos-related diseases can extend from ten to fifty years following initial exposure, meaning workers who handled the Coelex 60 Unitab Brick during its production years may only now be receiving diagnoses.

How Workers Were Exposed

Industrial workers generally represent the primary population at risk from exposure to the Coelex 60 Unitab Brick. Exposure scenarios for this type of refractory product were closely tied to the physical demands of installing, maintaining, and removing refractory linings in high-temperature industrial settings.

Installation and Cutting: When refractory bricks were cut, shaped, or fitted during installation, the mechanical action of sawing, grinding, or breaking the brick would release asbestos-containing dust into the surrounding work area. Workers without adequate respiratory protection in enclosed or poorly ventilated spaces faced direct inhalation of these airborne fibers.

Maintenance and Repair: Industrial furnaces, kilns, and boilers require periodic relining and repair. Workers performing maintenance tasks on refractory systems that included the Coelex 60 Unitab Brick would disturb aging and deteriorating materials, releasing previously bound chrysotile fibers. Heat cycling over time can degrade the structural matrix of refractory bricks, making them increasingly friable and prone to fiber release during handling.

Demolition and Replacement: The complete removal of refractory linings—whether during facility upgrades or equipment decommissioning—represented one of the highest-exposure activities associated with asbestos-containing refractory products. Breaking out old bricks and clearing debris generated significant dust loads, particularly before modern respiratory and containment protocols were in place.

Bystander Exposure: Workers in adjacent areas of a facility, including those not directly handling refractory materials, could also be exposed through the migration of asbestos-containing dust in shared ventilation systems or open industrial workspaces.

OSHA’s current permissible exposure limit (PEL) for asbestos is 0.1 fibers per cubic centimeter of air as an eight-hour time-weighted average. During the years the Coelex 60 Unitab Brick was in production and common use, workplace exposure standards were considerably less stringent, and enforcement was limited. Many workers in industrial settings during the 1970s and into subsequent decades had no practical means of knowing they were being exposed to asbestos fibers at potentially harmful levels.

Documented Product Identification

The following details are drawn from public asbestos litigation records, manufacturer catalog pages, technical manuals, and corporate history materials. Each item reflects the product as documented in those sources.

Documented asbestos-use period: 1953-1978

Corporate context: Kaiser Gypsum Company, Inc. operated as a manufacturer of gypsum wallboard, ceiling tiles, joint compounds, and related construction products. Service of process was handled through C. T. Corporation System in Los Angeles, California.

Brand identification: Products branded with KAISER GYPSUM name; Null-A-Fire for fire-rated wallboard; Permanente for cement products; Cover-Tex for texture products; K-Spray for spray textures

Documented asbestos components: asbestos fiber, vermiculite containing tremolite, chrysotile fiber.

Documented asbestos-component suppliers: the public records lists the following external suppliers of asbestos-bearing packing, gaskets, and seals used in conjunction with this manufacturer’s equipment — Harrison & Crossfield, Carmonia Chemical Co., Western Chemical Co., Philip Carey, Johns-Manville, Union Carbide, E. S. Browning, WR Grace / Libby, MT, Carey-Canadian Mines, Ltd..

Industries served: construction, building trades, drywall installation, acoustical ceiling installation.

Documented product lines:

  • Null-A-Fire Type X Wallboard (1954-1978). 5/8-inch thick interior wallboard used for walls and ceilings to provide partitions and fire resistance. — asbestos components: vermiculite containing tremolite.
  • Fire-Rated Mineral Fiberboard (1963-1974). Acoustical ceiling tile and suspended lay-in board with perforated or fissured design for acoustical treatment. — asbestos components: asbestos fiber.
  • Fire-Rated Ceiling Tiles. Ceiling tiles sold in boxes of various sizes. — asbestos components: asbestos fiber.
  • KAISER GYPSUM Joint Compound (1953-1975). Joint compound for finishing drywall seams. — asbestos components: asbestos fiber.
  • KAISER GYPSUM Finishing / Topping Compound (1961-1975). Finishing and topping compound for drywall applications. — asbestos components: asbestos fiber.
  • KAISER GYPSUM 3-Purpose Joint Compound (1968-1975). Multi-purpose joint compound for drywall finishing. — asbestos components: asbestos fiber.
  • KAISER GYPSUM One-Day Joint Cement (1968-1975). Fast-setting joint cement for drywall work. — asbestos components: asbestos fiber.
  • KAISER GYPSUM Pre-Mix Joint Compound (1959-1975). Ready-mixed joint compound for drywall finishing. — asbestos components: asbestos fiber.

Kaiser Gypsum used asbestos in joint compounds, texture products, ceiling tiles, wallboard, and cement products from 1953-1978. Union Carbide supplied CALIDRIA Asbestos (chrysotile) specifically for tape joint compound formulations.