WO-339 MC Gun — Keene Corporation

Product Description

The WO-339 MC Gun was an asbestos-containing product manufactured by Keene Corporation, a diversified industrial company that produced a broad range of construction, insulation, and fireproofing materials throughout much of the twentieth century. The “MC Gun” designation suggests this product was associated with a spray or projection application system, consistent with Keene’s involvement in spray-applied fireproofing and insulation technologies that were widely adopted across industrial, commercial, and institutional construction projects during the mid-to-late twentieth century.

Keene Corporation operated across several industrial segments, including building products and specialty materials, and supplied products to construction sites, manufacturing facilities, shipyards, and power generation plants. The WO-339 MC Gun falls within a product family that litigation records associate with multiple end-use categories, including floor tile applications, pipe insulation, refractory materials, spray fireproofing systems, and valves and steam traps — reflecting the versatility of asbestos-containing product lines during the era in which they were produced.

Because precise production dates have not been independently verified in publicly available documentation for this specific product designation, the WO-339 MC Gun is referenced in the context of Keene Corporation’s broader manufacturing history, which spans decades during which asbestos use was commonplace and largely unregulated in industrial product manufacturing.

Asbestos Content

Keene Corporation products in the categories associated with the WO-339 MC Gun — including spray fireproofing materials, pipe insulation, floor tiles, refractory compounds, and valve and steam trap assemblies — were historically formulated with asbestos mineral fibers as a primary functional ingredient. Chrysotile, amosite, and crocidolite asbestos varieties were all employed in various industrial product lines during the periods in question, depending on the thermal, structural, and fire-resistance demands of the intended application.

In spray fireproofing and refractory materials, asbestos provided critical heat resistance and structural cohesion. In pipe insulation products, asbestos fibers were valued for their thermal insulating properties and durability under high-pressure and high-temperature service conditions. In floor tile formulations, asbestos was used as a reinforcing binder. In valve and steam trap assemblies, asbestos-containing packing, gaskets, and insulation components were standard for sealing and thermal management.

Plaintiffs alleged in litigation that Keene Corporation was aware, or should have been aware, of the hazards associated with asbestos-containing materials in its product lines, and that adequate warnings were not provided to workers and end users who encountered these products in occupational settings.

The specific asbestos fiber type and percentage composition of the WO-339 MC Gun have not been independently confirmed in publicly available product documentation reviewed for this reference entry. However, litigation records document the product’s classification alongside other Keene asbestos-containing materials.

How Workers Were Exposed

Industrial workers represent the primary exposed population documented in connection with Keene Corporation asbestos-containing products, including those in the categories associated with the WO-339 MC Gun. Exposure pathways varied depending on the application context, but shared a common mechanism: the disturbance, application, mixing, cutting, removal, or proximity to asbestos-containing materials that released respirable fibers into the breathing zone.

Spray Fireproofing Applications: Workers involved in the application of spray-applied fireproofing materials faced among the most intensive exposure scenarios documented in litigation and industrial hygiene literature. The spray process itself — which projected asbestos-laden material under pressure onto structural steel and concrete surfaces — generated dense fiber clouds in enclosed or semi-enclosed spaces. Bystander workers, including ironworkers, electricians, pipefitters, and laborers working in adjacent areas, were also exposed without necessarily performing the application directly.

Pipe Insulation Work: Insulation installers and pipefitters who worked with asbestos pipe insulation products experienced repeated, sometimes daily, exposure during cutting, fitting, and finishing operations. Maintenance and repair workers who later disturbed pre-existing asbestos pipe insulation during service work — sawing, chipping, or removing deteriorated insulation — faced significant secondary exposures that litigation records document across multiple industrial sectors.

Refractory and High-Temperature Applications: Workers in foundries, steel mills, power plants, and similar heavy industrial environments who installed, repaired, or removed refractory materials containing asbestos were exposed during mixing and application, as well as during the demolition or replacement of worn refractory linings.

Floor Tile Installation and Removal: Tile setters and floor mechanics who installed asbestos-containing floor tiles using dry-cutting or abrasive methods generated substantial fiber release. Maintenance personnel who sanded, buffed, or removed existing tile installations faced comparable risks, particularly when working in enclosed spaces with limited ventilation.

Valves and Steam Traps: Pipefitters, maintenance mechanics, and boilerhouse workers who serviced, repaired, or replaced valve assemblies and steam traps encountered asbestos-containing gaskets, packing, and insulating components. Removal and replacement of these components — particularly in aging industrial facilities — could release significant quantities of respirable fibers.

Across all these exposure contexts, industrial workers generally may have gone years or decades without recognizing that the materials they handled contained asbestos, as product labeling and safety disclosures were frequently absent or inadequate during the periods of heaviest use.

This reference article is provided for informational purposes based on litigation records and publicly available documentation. It does not constitute legal advice. Individuals with potential asbestos exposure claims should consult a licensed attorney.