BPB Celotex
Ceiling tiles such as Protectone™, Safetone™ and Hytone™ Mineral Ceiling Products made from recycled content slag wool (up to 90%) and cellulose (about 20%). Other ingredients include clay, starch and perlite.

U.S.Gypsum Co.
Ceiling panel products are 25% to 95% recycled content from post-consumer waste paper, cornstarch, slag and gypsum. In some processes, corn and wheat starch are used as binders.