16 CFR 460.2: What is home insulation.

Insulation is any material mainly used to slow heat flow. It may be mineral or organic, fibrous, cellular, or reflective. It may be in rigid, semirigid, flexible, or loose-fill form. Home insulation is for use in old or new homes, condominiums, cooperatives, apartments, modular homes, or mobile homes. It does not include pipe insulation. It does not include any kind of duct insulation except for duct wrap. It also includes insulation developed and marketed for commercial or industrial buildings that is also marketed for and used in residential buildings.