USGS Report: http://pubs.usgs.gov/of/2005/1165/508OF05-1165.html
The best compositional match for the majority (>85%) of WTC glass fibers is slag wool -- a by-product of pig iron production
NAIMA, the North American trade association for manufactures of fiber glass, www.naima.org: slag & rock wool are used for building insulation or other industrial uses:
o they are a primary constituent of ceiling tile and sprayed fire proofing for commericial buildings.
o they are non-combustible with melting temp close to 2000 deg F and have excellent thermal resisitance
"Why doesn't the paper burn". The reason is in both figures everything is covered with this highly non-combustible dust. Fires are confined very locally to highly flammable sources and cannot easily spread.
