Hi Susan,
I am a fan of the batt insulation, but I can see where a crawl space attic would be a good fit for blown in insulation.
The stuff I see most often is cellulose based...
newspaper, cardboard, even bluejeans. Fairly innocuous, but they do add fire and bug retardants to it.
I do see that there is a rockwool blown in insulation option now... which is also fairly innocuous. It is the left over slag from making steel, where they super heat it and spin fibers. Naturally flame and bug resistant.
"The future is something which everyone reaches at the rate of sixty minutes an hour, whatever he does, whoever he is." C.S. Lewis
"When the whole world is running towards a cliff, he who is running in the opposite direction appears to have lost his mind." C.S. Lewis