Manufacturer: BASF Corporation (successor-in-interest to entities that marketed Micafil-branded expanded-vermiculite loose-fill insulation in North America) Product Category: Loose-Fill Vermiculite Insulation / Ceiling and Attic Fill

Product Description

Micafil was a brand of expanded-vermiculite loose-fill insulation marketed for pouring into ceiling joist cavities, attic floors, and hollow-block masonry walls. It competed directly with the Zonolite-branded loose-fill vermiculite insulation associated with W.R. Grace & Co. and its Libby, Montana vermiculite mine. Loose-fill vermiculite was widely specified in residential and light-commercial construction from the 1950s through the early 1980s because it was pourable, non-combustible, and provided modest thermal resistance with essentially no application labor beyond opening the bag and raking the fill flat.

Plaintiffs alleged in publicly filed U.S. asbestos personal-injury and wrongful-death litigation that Micafil loose-fill vermiculite insulation allegedly contained tremolite and actinolite amphibole asbestos as a mining contaminant. According to allegations in publicly filed litigation records, vermiculite ore from certain pre-regulatory-era mining sources was allegedly cross-contaminated with amphibole asbestos veins running through the host rock; expansion (exfoliation) of the raw ore into the puffed insulation product allegedly did not remove the amphibole fibers, which were then distributed throughout the finished loose-fill product in bagged form.

Documented asbestos-use period, according to publicly filed litigation records: approximately 1950s through 1984, after which loose-fill vermiculite insulation was progressively withdrawn from residential and commercial specification and remediation guidance was issued by EPA.

Workers Exposed

Insulators and insulation contractors were the primary trade allegedly exposed to Micafil loose-fill vermiculite. Publicly filed litigation records allege that insulators cut open paper bags of loose-fill and poured the vermiculite directly into attic joist cavities and hollow-block wall cores, raking the fill flat with hand tools. Bag opening and pouring allegedly released respirable amphibole fiber into the installer’s breathing zone within confined attic spaces.

Carpenters framing ceiling assemblies and installing attic access hatches allegedly worked around freshly poured Micafil and were exposed during subsequent framing and finish work in ceilings that had already been insulated.

Electricians running wire in attics and ceiling plenums where loose-fill vermiculite had been installed allegedly disturbed the fill during outlet-box installation, junction-box modifications, and re-wiring work — releasing amphibole fiber from the aged fill.

HVAC installers retrofitting ductwork and equipment through insulated attic and ceiling spaces allegedly disturbed loose-fill Micafil during duct runs, register cut-ins, and equipment placement.

Renovation workers and home remodelers decades later allegedly disturbed installed Micafil during attic conversion, ceiling replacement, insulation removal, and blown-in-insulation retrofit projects. Publicly filed litigation records allege that homeowner and small-contractor removal of aged loose-fill vermiculite — without wet-methods or respiratory protection — released substantial concentrations of respirable tremolite and actinolite into the work area.