Hamilton Materials Asbestos-Fibered Joint Sealant

Product Description

Hamilton Materials, Inc. marketed a family of asbestos-fibered joint sealants and mastic compounds for use in the sealing of building joints, roof-flashing terminations, coping details, penetrations, and exposed exterior seams from approximately the 1960s into the 1970s. Sold in cans and cartridges through building-supply, hardware, and roofing-distributor channels, the fibered sealant was designed for hand-application by trowel, putty knife, or caulk gun to fill and weatherproof joints subject to thermal movement and water infiltration.

Plaintiffs have alleged in publicly filed U.S. asbestos personal-injury and wrongful-death litigation that Hamilton Materials joint sealant was formulated with chrysotile asbestos incorporated as a fibrous reinforcement that improved tensile strength, non-slump body, and crack-bridging performance across expansion joints. According to publicly filed asbestos litigation records, the product was applied on residential, commercial, industrial, and institutional construction across the United States during its asbestos-containing production run.

Workers Exposed

Plaintiffs allege the following trades were exposed to airborne chrysotile fibers from Hamilton Materials joint sealant:

• Sealant applicators, painters, and finish tradespeople who opened cans, extruded cartridge material, and troweled the fibered sealant into joints and cracks — allegedly encountering fibers during raw-material handling and during tool-cleanup with rags.
• Roofers who used the fibered sealant to weatherproof flashing terminations, coping seams, and roof-deck penetrations, allegedly inhaling fibers during application and later during re-roof tear-off of the cured material.
• Carpenters and remodel workers who scraped, cut, or removed cured Hamilton sealant during renovation — allegedly liberating chrysotile fibers from the disturbed matrix.
• Demolition laborers who saw-cut and demolished joints, walls, and roof assemblies containing cured Hamilton sealant, allegedly generating airborne fibers during structural removal.