It is known for many years that the Fiberglass substance is suspected of being carcinogenic. I read that the tiny fiberglass fibers are carried to the air, and then enter your lungs when you breath. Inside your lungs, the fibers might cause chnages in some cells DNA, which might cause them to divide uncontrollably, leading to cancerous tumours, God forbid. I think that it could happen only if the fiberglass is not covered, or covered by something which still allows the fiberglass fibers to go through it. From the bass absorbers projects that I've seen, the fiberglass was always covered with some fabric, but the question is, can't the fibers go out through this fabric ?. There is a very large circulation of air, mainly into, but I'm sure some out from the bass absorber. Couldn't it be that the air which goes out from the bass absorber will carry the suspected carcinogenic fiber into the air, and from there to your lungs ?. Think about this, you are inside a pretty small room, most of the time without openings while you're in. What are your thought about this issue ?.