RSPA-SOL are thermal insulation products capable of withstanding continuous operating temperatures up to 1260°C (2300°F). Type RSPA-SOL papers are designed to have enhanced in-vitro solubility characteristics which enable them to meet European regulatory requirements for synthetic vitreous fibers (European regulatory requirements directive 97/69/EC).

These unique papers exhibit excellent chemical stability and resistance to attack from most corrosive agents. Exceptions include hydrofluoric acid, phosphoric acid and strong alkalis. Type RSPA-SOL papers also provide superior wetting resistance to molten aluminum alloys at high temperatures. Type RSPA-SOL papers will generate small amounts of smoke and trace element outgassing during initial exposure to temperatures above 230ºC (446ºF).