BOF Cote / BOF Patch — NARCO Basic Oxygen Furnace Refractory Products

Product Description

BOF Cote and BOF Patch were specialty refractory products manufactured by North American Refractories Company (NARCO) for use in basic oxygen furnace (BOF) steelmaking applications. These products were produced and distributed primarily during the period spanning approximately 1965 through 1975, a decade that coincided with the rapid expansion of basic oxygen furnace technology across the American steel industry.

The basic oxygen furnace, which displaced the older open-hearth steelmaking process throughout this era, required continuous refractory maintenance to withstand the extreme thermal and mechanical stresses generated during steel production. Molten metal temperatures inside a BOF vessel regularly exceed 2,900 degrees Fahrenheit, creating conditions that progressively erode the furnace lining. BOF Cote and BOF Patch were formulated specifically to address this challenge — BOF Cote as a protective coating applied to furnace linings and BOF Patch as a patching and repair compound used to fill voids, spalled areas, and worn sections of the refractory lining between production heats.

NARCO was among the leading refractory manufacturers in the United States during the mid-twentieth century, supplying steel mills, foundries, and industrial facilities with a broad range of high-temperature materials. The company’s BOF product line was widely used at integrated steel plants throughout the industrial regions of the United States, including facilities concentrated in Pennsylvania, Ohio, Indiana, West Virginia, and other steel-producing states.

Asbestos Content

BOF Cote and BOF Patch, as formulated during the 1965–1975 production period, contained asbestos as a component of their refractory composition. Asbestos was incorporated into refractory products of this type for several functional reasons. Its thermal resistance properties helped the material withstand rapid temperature cycling, its fibrous structure contributed to the binding and cohesion of the patching compound, and it provided a degree of thermal insulation that could slow heat penetration through applied coatings and patches.

The inclusion of asbestos in refractory patching and coating materials was common industry practice during this period, and NARCO’s BOF product line reflected that standard formulation approach. Trust fund documentation and litigation records associated with NARCO products confirm the asbestos-containing nature of these refractory compounds. The specific fiber types used in industrial refractory applications of this era typically included chrysotile and, in some formulations, amphibole varieties, though the precise mineral composition of individual NARCO product batches is reflected in product and trust documentation.

It was not until the 1970s, following the publication of epidemiological research linking asbestos exposure to serious disease, that regulatory attention began to focus on asbestos-containing refractory materials in industrial settings. OSHA’s first asbestos standards took effect in 1972, though widespread reformulation of refractory products continued into subsequent years as regulations evolved.

How Workers Were Exposed

Industrial workers employed at steel mills and metalworking facilities that used basic oxygen furnace technology faced potential asbestos exposure through the handling, application, and maintenance of products such as BOF Cote and BOF Patch. The nature of refractory repair work in BOF operations created several distinct exposure pathways.

Mixing and preparation was a primary source of exposure. Workers who prepared BOF Patch compounds for application often handled dry or semi-dry refractory materials that could release respirable asbestos fibers during mixing, especially in enclosed or poorly ventilated areas near the furnace vessel.

Application work brought workers into close proximity with asbestos-containing materials. Refractory repair crews who applied BOF Cote or BOF Patch to furnace linings — often working under hot conditions and time pressure between production heats — handled these materials directly and could disturb fiber-containing surfaces during application.

Maintenance and removal activities posed significant exposure risk. As applied refractory coatings and patches deteriorated under operating conditions, they required removal before fresh material could be applied. Scraping, chipping, or pneumatic removal of worn refractory material containing asbestos could generate substantial airborne fiber concentrations.

Nearby trade workers in the steel mill environment — including crane operators, millwrights, electricians, and general labor — could experience secondary or bystander exposure when refractory repair work was performed in shared workspaces without adequate containment or respiratory protection.

The BOF operating environment itself compounded exposure risks. Steelmaking facilities were often loud, physically demanding, and not historically equipped with the ventilation and personal protective equipment infrastructure that later OSHA standards would require. Workers in these environments frequently spent entire careers in close contact with asbestos-containing refractory materials without awareness of the associated health hazards.

Diseases associated with occupational asbestos exposure, including mesothelioma, asbestosis, and lung cancer, can have latency periods of twenty to fifty years, meaning workers exposed to NARCO BOF products during the 1965–1975 period may be receiving diagnoses today.

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.

Corporate context: Formed in 1929 through the merger of several refractory companies including Queen’s Run, Crescent, and Eltra, among others. Owned by Eltra until 1979, then by Allied Signal (Allied) from 1979 to 1986, after which ownership transferred to banks and investors. Headquartered in Cleveland, Ohio.

Brand identification: Narco

Industries served: steel, iron.

North American Refractories Company (Narco) manufactured refractory materials used primarily in high-temperature industrial applications such as steel and iron processing. The company operated approximately eleven manufacturing facilities and a research center in Curwensville, Pennsylvania.