Asbestos in Plaster Explained
Various forms of plaster have been around for thousands of years, used in building construction, artistry, and even medical applications. Plaster starts as a pasty substance that’s made from minerals and water and dries into a sturdy, solid form.
The three most common types of plaster today include:
- Gypsum/Plaster of Paris
Until the mid-1980s, asbestos was commonly added to plaster. It was an inexpensive way to increase the plaster’s ability to insulate buildings and resist fire.
Asbestos continued to make its way into some types of plaster through cross-contamination despite its known danger.
Vermiculite is frequently mixed with cement plaster to create mortar, and some vermiculite mines also contain asbestos. The most famous vermiculite mine is Montana’s Libby Mine, which was a major global supplier of vermiculite until its closure in 1990 amidst massive litigation.
Although miners and plaster manufacturers are more aware of asbestos contamination in mines today, it’s not clear whether all current vermiculite mines across the globe are asbestos-free. Therefore, it’s possible that cross-contamination may continue to this day.