Armaspray / Armstrong Limpet Spray / Armstrong Sprayed Limpet

Product Description

Armaspray — also marketed under the names Armstrong Limpet Spray and Armstrong Sprayed Limpet — was a spray-applied fireproofing and thermal insulation product manufactured by Armstrong World Industries. The product was applied during the construction and renovation of commercial, industrial, and institutional buildings throughout its production period from approximately 1966 to 1974.

Spray-applied fireproofing products of this era served a critical structural function: when applied to steel beams, columns, decking, and other structural elements, they slowed heat transfer during a fire, helping to maintain the integrity of load-bearing components. Armaspray was part of a broader category of sprayed limpet insulation products that became widespread in mid-twentieth-century construction, particularly as high-rise buildings, industrial facilities, and large public structures required rapid, cost-effective methods of achieving fire ratings mandated by building codes.

Armstrong World Industries was a major manufacturer of building materials and flooring products headquartered in Lancaster, Pennsylvania. The company’s involvement in asbestos-containing construction products placed it at the center of asbestos litigation that ultimately led to a structured bankruptcy reorganization and the establishment of a dedicated asbestos injury trust.

Asbestos Content

Armaspray and its related Armstrong Limpet Spray and Armstrong Sprayed Limpet formulations contained chrysotile asbestos as a functional ingredient. Chrysotile, sometimes referred to as “white asbestos,” is a serpentine-form mineral fiber that was widely used in building products during the twentieth century because of its tensile strength, heat resistance, and binding properties.

In spray-applied fireproofing products, chrysotile fibers were mixed with binding agents and other materials to produce a semi-wet slurry that could be sprayed onto structural surfaces through pressurized application equipment. Once dried and cured, the asbestos-reinforced coating adhered to steel and other substrates and provided the insulating and fire-retardant properties for which it was specified.

The hazardous nature of chrysotile asbestos has been well established through decades of occupational health research and regulatory action. The U.S. Environmental Protection Agency classified asbestos as a hazardous air pollutant under the Clean Air Act, and the Occupational Safety and Health Administration (OSHA) established permissible exposure limits for airborne asbestos fibers, reflecting the agency’s determination that inhalation of asbestos fibers causes serious disease, including mesothelioma, asbestosis, and lung cancer. Spray-applied asbestos products are specifically addressed under OSHA’s asbestos standards and under the Asbestos Hazard Emergency Response Act (AHERA), which governs asbestos-containing materials in school buildings.

The production of Armaspray was discontinued by 1974, consistent with the broader industry move away from asbestos-containing spray fireproofing following increasing regulatory scrutiny and public health concerns during that period. However, because the product was installed in buildings that remained in service for decades, occupational exposures continued well beyond the manufacturing end date — particularly during renovation, demolition, and maintenance activities.

How Workers Were Exposed

Workers in industrial and construction settings faced exposure to asbestos fibers from Armaspray and Armstrong Limpet Spray products through multiple pathways over many years.

During Original Application. Workers who mixed, loaded, and sprayed limpet products were exposed to high concentrations of airborne asbestos fibers. The mechanical process of spraying a slurry containing chrysotile asbestos generated fine particulate that dispersed throughout the immediate work environment. Other trades working in the same area — ironworkers, electricians, plumbers, and general laborers — could also be exposed through bystander contact with airborne fibers.

During Disturbance, Renovation, and Demolition. Because Armaspray was sprayed onto structural elements in buildings constructed between 1966 and 1974, those buildings required ongoing maintenance, renovation, and eventually demolition. Any activity that disturbed the dried limpet coating — cutting, drilling, sanding, abrasive removal, or high-pressure washing — had the potential to release asbestos fibers into the air. Industrial workers performing maintenance on equipment or structures inside buildings where Armaspray had been applied were at risk whenever the coating was damaged or disturbed.

Occupational Settings. Industrial facilities, including manufacturing plants, power generation facilities, warehouses, and processing plants, were common venues for spray-applied fireproofing during the construction boom of the 1960s and early 1970s. Workers employed in these environments over extended periods faced potential cumulative exposure depending on the condition of the installed product and the nature of work performed nearby.

The latency period for asbestos-related diseases — often 20 to 50 years between first exposure and clinical diagnosis — means that workers exposed to Armaspray during its production and installation years may be receiving diagnoses today. Diseases associated with occupational asbestos exposure include malignant mesothelioma (a cancer of the lining of the lungs, abdomen, or heart), asbestos-related lung cancer, asbestosis (progressive fibrotic scarring of the lung tissue), and pleural disease including thickening and effusion.