I've had a brick kiln for years, dad has used a brick kiln for about as long as I've been alive. My sister and my mom both had or have brick kilns. I've never had dust or chips from bricks fall into my glass work. I've never known anyone tho complain about debris falling into their glass work. Cracked bricks can be repaired or replaced. I've also used fiber blankets to cool hot glass when working away from home. No problems with fiber blankets either... YMMV