Fiberglass insulation inspection and quality control specialists divide fiberglass insulation into three categories when creating an inspection procedure. The first category is electrical (Type E). This electrical fiberglass insulation is used as electrical insulation tape. Another category is chemical fiberglass insulation (Type C) , which has superior acid resistance. The final category for fiberglass insulation is thermal insulation (Type T), which is used in walls, and attics in residential and commercial buildings.