•The secret to cool bodies and glazes is a lot of testing.
•The secret to know what to test is material and chemistry knowledge.
•The secret to learning from testing is documentation.
•The place to test, do the chemistry and document is an account at https://insight-live.com
•The place to get the knowledge is https://digitalfire.com
One source stated "Perlite is insoluble, stable, and inert with no known effects of exposure; can be treated as an innocuous dust. Perlite is partially soluble in hydroflouric acid".
However Perlite creates an exceedingly fine dust composed of volcanic glass particles, anyone that has worked with it can testify to this. The hazards thus need to be investigated more thoroughly.
Out Bound Links
In Bound Links
Perlite - Expanded volcanic glass
By Tony Hansen