Mineral wool, best known by its trade name "Rock Wool," and is similar
to glass fiber insulation except the raw material is steel, copper, or lead
slags or naturally occurring rock rather than glass. Rock wool's insulating
ability is about 10 percent greater than that of fiberglass. Since
mineral wools are made from rock or slag melted at temperatures over 219°F,
the base material of batt or blowing wool is non-combustible. However, binders
added to them may be flammable. Mineral wools can be irritating, therefore masks,
gloves, long sleeves and other protective apparel should be worn when handling
this type of insulation.
