Encapsolated it is fine, as a slurry used as a liner. I was refering as being loose to fill the void that was suggested by the poster.
The second reason this:
An article published in the Salt Lake Tribune on December 3, 2006 reported that vermiculite and Zonolite (a brand of insulation made from vermiculite) had been found to contain asbestos, which had led to cancers such as those found in asbestos related cases. The article stated that there had been a "cover-up" by W.R. Grace Company and others regarding the health risks associated with vermiculite and that several sites in the Salt Lake Valley had been remediated by the EPA when they were shown to be contaminated with asbestos. W.R. Grace Company has vigorously denied these charges.
Although not all vermiculite contains asbestos, some products were made with vermiculite that contained asbestos until the early 1990s. Vermiculite mines throughout the world are now regularly tested for it and are supposed to sell products that contain no asbestos. The former vermiculite mine in Libby, Montana did have asbestos — in fact, it was found to have developed underground with and to be co-mingled with significant amounts of asbestos.
Pure vermiculite does not contain asbestos and is non-toxic, but it can become contaminated over long periods if there is a presence of a secondary mineral called diopside. After millions of years of weatherization, the biotite turns into vermiculite and the diopside turns into asbestos. This appears to have happened to the vermiculite deposit at the Libby, Montana mine, and numerous people were unknowingly exposed to the harmful dust of vermiculite that contained asbestos. Unfortunately, the mine had been operating since the 1920s, and environmental and industrial controls were virtually non-existent until the mine was purchased by the W.R. Grace Company in 1963. Yet, knowing the potential for human health risks, the mining company still continued to operate there until 1990. Consequently, many of the former miners and residents of Libby had been affected and continue to suffer health problems. Over 200 people in the town died from asbestos-related disease due to contamination from vermiculite mining from nearby Zonolite Mountain, where soil samples were found to be loaded with fibrous tremolite (known to be a very toxic form of asbestos), and countless others there who insulated their homes with Zonolite have succumbed to asbestos-related diseases, most of whom never were employed in environments where asbestos was an issue.[3]
After a 1999 Seattle Post-Intelligencer story claimed that asbestos-related disease was common in the town, the EPA, in response to political pressure, made cleanup of the site a priority and called Libby the worst case of community-wide exposure to a toxic substance in U.S. history.[4][5] [6] The EPA has spent $120 million in Superfund money on cleanup.[7] In October 2006, W. R. Grace and Company tried to appeal the fines levied on them from the EPA, but the Supreme Court rejected the appeal.[8] The United States government is also pursuing criminal charges against several former executives and managers of the mine for allegedly disregarding and covering up health risks to employees.[9] They are also accused of obstructing the government's cleanup efforts and wire fraud. To date, according to the indictment, approximately 1,200 residents of the Libby area have been identified as suffering from some kind of asbestos-related abnormality.[10] The criminal proceedings are ongoing as of July 2007.[11]
Since the 1920s, vermiculite had been extracted from the Libby deposit under the commercial name Zonolite. The Zonolite brand was acquired by the W.R. Grace Company in 1963. Mining operations on the Libby site stopped in 1990 in response to asbestos contamination. While in operation, the Libby mine may have produced 80% of the world's supply of vermiculite.[12] The United States government estimates that vermiculite was used in more than 35 million homes but does not recommend its removal. Nevertheless, homes or structures containing vermiculite or vermiculite insulation dating from before the mid 1990s, and especially those known to contain the "Zonolite" brand, may contain asbestos, and therefore may be a health concern.
