Product Description

USG Perlite Plaster was a lightweight, perlite-aggregate gypsum basecoat plaster marketed by United States Gypsum Company (USG) for interior wall and ceiling construction from approximately the 1950s through the 1970s. The product combined calcined gypsum with expanded perlite mineral aggregate to produce a lightweight basecoat plaster suitable for application over gypsum lath, metal lath, and masonry substrates in residential, commercial, and institutional construction. Its perlite-based formulation reduced dead load compared with traditional sand-aggregate plasters while retaining workability, fire resistance, and finish-coat compatibility.

Plaintiffs have alleged in publicly filed U.S. asbestos personal-injury and wrongful-death litigation that USG Perlite Plaster was formulated with chrysotile asbestos incorporated as a fibrous reinforcement additive throughout portions of its production run. According to publicly filed asbestos litigation records, the product was distributed nationally to plastering contractors and building-supply houses and was applied by union and non-union plasterers on residential, school, hospital, commercial, and light-industrial projects.

Workers Exposed

Plaintiffs allege that the following trades were exposed to airborne chrysotile fibers from USG Perlite Plaster during ordinary application, finishing, and demolition activities:

  • Plasterers who scooped, mixed, and hand-troweled the dry perlite-plaster powder from bags — allegedly generating visible dust clouds during pour-off, hawk loading, and hand-troweling in enclosed rooms.
  • Drywall finishers and tapers who worked on jobsites where perlite basecoat had been applied and later scraped, sanded, or feathered edges into adjoining drywall assemblies.
  • General laborers who mixed plaster in wheelbarrows and box mixers, swept dry plaster residue, and hauled empty bags — allegedly inhaling dust from dry-side handling.
  • Carpenters and demolition workers who cut, chipped, or demolished set perlite-plaster walls and ceilings during renovation, exposing themselves to fibers allegedly liberated from the disturbed matrix.