scubadoo
Fish Crazy
Insulation I think. I always understood that rock wool was a mix of finely shredded newspaper and chemicals and if you use it a dust mask and gloves are a must since it can damage your lungs. Fiberglass you use gloves to prevent those tiny splinters from getting ya. They're like brushing against nettles. I use a mask due to the dust particles it can throw . Maybe they make it differently there.
OK now they may make rockwool differently in the US - I cant comment about that, but one thing is for certain, in the UK it is a MINERAL wool insulation product that is made from ROCK !
Look here for proof :
Rockwool Creation