Armstrong Sealers

Product Description

Armstrong Sealers were industrial sealing compounds manufactured by Armstrong World Industries during the period spanning 1939 through 1957. These products were designed to create reliable, pressure-resistant seals in industrial piping systems, mechanical assemblies, and equipment joints where leakage prevention was critical to safe and efficient operations.

Armstrong World Industries, headquartered in Lancaster, Pennsylvania, was a well-established manufacturer of flooring, insulation, and industrial materials throughout the twentieth century. The company’s sealers were marketed to a broad range of industrial facilities, including manufacturing plants, refineries, chemical processing operations, and utility installations, where robust sealing solutions were essential for maintaining system integrity under demanding thermal and mechanical conditions.

The sealers were formulated as compounds intended to fill gaps, coat threaded pipe connections, and form tight bonds between mating surfaces in industrial equipment. Their applications spanned settings where high temperatures, pressure fluctuations, and chemical exposure placed significant stress on sealing materials, making durability and heat resistance primary product requirements during the period of manufacture.

During the years these products were sold, asbestos-containing materials were widely used across industrial sealant and gasket formulations. Asbestos was considered a technically advantageous additive for its resistance to heat, its fibrous binding qualities, and its relative abundance as a raw material. Armstrong Sealers reflected the broader industrial practice of that era, incorporating asbestos as a functional component of the compound’s design.

Asbestos Content

Armstrong Sealers produced between 1939 and 1957 contained chrysotile asbestos. Chrysotile, commonly referred to as white asbestos, is the most widely used form of asbestos in industrial products and belongs to the serpentine mineral group. Its long, curly fibers made it well-suited for incorporation into sealing compounds, where it contributed to the product’s ability to withstand elevated temperatures and mechanical stress without breaking down.

Chrysotile was used extensively in gasket and packing materials throughout mid-twentieth century industrial manufacturing. In sealing compounds specifically, asbestos fibers were typically blended into a carrier medium, creating a paste or semi-solid material that could be applied to joints and connections. The fibers provided structural reinforcement to the seal while also imparting resistance to heat degradation—a critical property in steam lines, boiler connections, and high-temperature process equipment.

Although chrysotile is sometimes described as less hazardous than amphibole forms of asbestos such as crocidolite or amosite, regulatory and scientific consensus—including findings reflected in OSHA standards and AHERA rulemaking—confirms that all forms of asbestos are human carcinogens capable of causing mesothelioma, lung cancer, and asbestosis when inhaled. There is no established safe level of exposure to any asbestos fiber type.

How Workers Were Exposed

Industrial workers who handled, applied, or worked in proximity to Armstrong Sealers during the product’s years of manufacture and use faced potential exposure to airborne chrysotile asbestos fibers. The nature of sealing compound work created multiple pathways through which fiber release could occur.

Workers applying the sealers to pipe threads, flanges, or equipment joints would have handled the compound directly, often manipulating it with bare hands or tools. If the compound was in a dry or semi-dry state during application—or if partially cured material was disturbed during maintenance and repair activities—asbestos fibers could become airborne. Sanding, scraping, or removing old sealer material during equipment overhauls was particularly likely to generate dust containing respirable fibers.

In industrial plant environments, maintenance operations on pipelines and mechanical systems were routine. Workers engaged in repairing or replacing sealed connections would have encountered previously applied Armstrong Sealers in various states of age and degradation. Aged sealing compounds can become brittle and friable over time, increasing the likelihood that disturbance during maintenance will release fibers into the breathing zone.

General industrial workers in facilities where these sealers were regularly used—including pipe fitters, millwrights, boilermakers, maintenance mechanics, and plant workers in general—could face secondary exposure from airborne fibers generated by nearby colleagues working directly with the product. In enclosed industrial environments with limited ventilation, fiber concentrations could accumulate without adequate dissipation.

Workplace exposure standards for asbestos were not established in the United States until OSHA issued its first asbestos regulations in 1971. During the entire production period of Armstrong Sealers (1939–1957), no enforceable federal workplace exposure limits existed, and industrial hygiene controls in many facilities were minimal or absent. Workers of that era typically had no respiratory protection, received no hazard warnings from manufacturers, and were not informed of the potential long-term health consequences of asbestos inhalation.

The latency period for asbestos-related diseases—particularly mesothelioma, which can take 20 to 50 years to develop after initial exposure—means that individuals who worked with or around Armstrong Sealers during this period may only have received diagnoses in subsequent decades, long after their occupational exposure occurred.

Armstrong World Industries has no active asbestos bankruptcy trust associated specifically with Armstrong Sealers as a gasket and packing product. Armstrong World Industries did file for Chapter 11 bankruptcy protection in 2000, and the Armstrong World Industries Asbestos Personal Injury Settlement Trust was established to resolve asbestos personal injury claims. However, individuals seeking compensation for exposure to Armstrong Sealers should consult with an asbestos attorney to assess current eligibility and claim pathways, as trust coverage and approved product lists are subject to specific documentation requirements.

For individuals whose exposure history does not align with an active trust, civil litigation remains an available avenue. Litigation records document claims brought by industrial workers and their families alleging that exposure to asbestos-containing products, including industrial sealers and compounds, caused serious and fatal diseases including mesothelioma, lung cancer, and asbestosis. Plaintiffs alleged in such cases that manufacturers had knowledge of the hazards associated with asbestos-containing products and failed to adequately warn workers or provide safety information during the decades these products were in use.

Individuals who believe they were exposed to Armstrong Sealers or similar asbestos-containing sealing compounds and have subsequently been diagnosed with an asbestos-related disease should consider the following steps:

  • Consult a qualified asbestos attorney with experience in occupational exposure claims to evaluate the specific facts of their case and identify all potentially responsible parties.
  • Document work history as thoroughly as possible, including employers, job sites, dates of employment, and specific tasks involving sealing compounds or nearby asbestos-containing materials.
  • Obtain medical documentation from a physician experienced in diagnosing asbestos-related conditions, as proper medical records are essential to any legal claim.
  • Act within applicable statutes of limitations, which vary by state and typically begin running from the date of diagnosis rather than the date of exposure.

Given the long latency periods associated with asbestos-related diseases, many individuals exposed during the 1939–1957 production window of Armstrong Sealers may still be within legally actionable timeframes following a recent diagnosis. Legal consultation should be sought promptly upon any confirmed diagnosis of mesothelioma, asbestosis, or asbestos-related lung cancer.