[Zeke]

Grey thin cardboard is classic description of AB. Paint it with a primer and it's as safe as ever.

When you work with it, wet it with a spritzer. That's how it's removed. If you have AB ducting in the attic it's' too late to think about a completely AB free attic space, so don't worry about it. Wear an M95 mask and you're good.

If you expose the attic space to the living space all you need is a HEPA vac and a thorough cleaning before occupying.

I have a CA cert for handling AB.