FAQ about Vermiculite
Q: If I bring you a bag of vermiculite, can you test it for me?
A: Yes, and no, but mostly no. The short of it is this. Polarized Light Microscopy (or PLM for short) can not tell you if your vermiculite DOESN’T contain asbestos. The reason being that there are entirely too many nooks and cranny’s in the stuff for asbestos fibers to hide. It’s akin to trying to catch minnows with a shark net. See https://www.labcor.net/vermiculite.html for more information.
Q: How, then, can I know for sure if my vermiculite insulation does or doesn’t contain asbestos?
A: The best, and most for sure way, to test for the presence of asbestos in vermiculite is to have it tested by use of an electron scan microscope. LabCorp of Seattle has the proper equipment and skill to do so. You can call them and ask what their protocol is for sampling vermiculite. The link to their Seattle lab is https://www.labcor.net/seattle-information.html
For more information about vermiculite and the limitations of testing it with PLM, please visit the following links.
This is an article put out a few years ago about vermiculite. It says that the best and most sure way, to definitively determine if vermiculite does or does not contain asbestos is by TEM (Electron Scan Microscope).
https://eia-usa.org/images/downloads/Newsletters/march15newsletter.pdf
This is a study by EMSL on why PLM analysis of vermiculite is not suitable.