You may have come across it in between the floor joists of your attic, or in between the studs of your walls - a lightweight, granular material that looks a bit like gravel, but seems almost as light as air.
This material is known as vermiculite. Vermiculite is a term for a group of minerals that, when heated, expand into a worm-like structure. In fact, the term vermiculite itself references this characteristic. The latin word "vermiculare" means "to breed worms," and the suffix "ite" means "mineral" or "rock".
When expanded, vermiculite has extremely low mass compared to its volume. This makes it terrific for insulation purposes. In addition, it has quite a large chemically active surface area, which makes it ideal for certain laboratory and commercial applications. It is also used as a soil additive and construction aggregate. And on top of all these wonderful properties, vermiculite in and of itself is non-toxic.
So, if vermiculte is such an ideal, non-toxic material, what is the concern? How is it that vermiculite has some homeowners scratching their heads and wondering what to do with the stuff?
The answer is that some vermiculite can pose a health hazard because it has been cross-contaminated with asbestos.
Some of the vermiculite veins running through areas of rock crossed with veins of asbestos. Thus, when the vermiculite was extracted, so too was the asbestos.
Certainly not all vermiculite contains asbestos. In fact, it is most likely that most vermiculite is non-asbestos containing.
The questions then is, why then does the EPA encourage homeowners to assume that all vermiculite found in homes should be presumed to be asbestos, regardless of what any laboratory analysis might reveal?
What the EPA has discovered is that traditional methods of asbestos bulk sample analysis are not reliable when it comes to vermiculite. In tests performed by the EPA, vermiculite in homes slated for demolition was sampled and tested and found to be free of asbestos. However, air samples taken during demolition showed high levels of airborne asbestos. This asbestos was directly tied to the vermiculite particles. As it turns out, something about the characeristics of vermiculite make it extremely difficult for it to be analyzed reliably for asbestos.
So, although various asbestos analytical laboratories offer augmented analysis methods for vermiculite, the EPA encourages inividuals to always consider it to be asbestos-containing. This does not mean that if you have vermiculite insulation in your home you must remove it. Quite the contrary. Just HAVING the vermiculite in the home is not a problem - potential hazards are introduced when the material is disturbed and made airborne.
So, if you are going to perform a renovation, or you discover vermiculite in the middle of a demolition project, stop before it is disturbed and have it removed by certified asbestos abatement professionals.
If you have any questions about vermiculite or other EHS issue please submit it by pressing the button below. One of our professional staff memebers will respond within 24 - 48 hours.