What year did they stop usig vermiculite?

Vermiculite use significantly declined after the late 1970s when it was discovered that some sources, particularly the Libby mine in Montana, were contaminated with asbestos. This led to increased health concerns and regulatory actions. While vermiculite itself is not inherently hazardous, the asbestos-contaminated versions were phased out of use, and by the 1990s, most commercial production of vermiculite had shifted to safer sources. However, vermiculite is still used in various applications, provided it is sourced from asbestos-free deposits.