Vermiculite plant had no asbestos dust control devices before 1970s

Vermiculite was exfoliated at Vermiculite Northwest/W.R.Grace from the early 1950s until the plant closed in 1993.

The VNW plant had two primary manufacturing processes. The facility and manufacturing processes were described in company records. It should be noted that records describe facility processes in 1988, and that prior to the 1970s baghouses and other dust control devices were not installed, resulting in an increased risk of exposures for workers and community members before 1975.

The Libby vermiculite that was shipped to the site was grade #0, #1, #2, #3, and #4. Products made at this site included, Monokote, Zonolite insulation, acoustical plaster, and soil amendments, including Terra-Lite, and Redi-Earth.