Comprised of natural cotton composed of recycled denim, the EcoShield is a natural fiber insulation. According to the manufacturer, the liner provides superb sound absorption, consistent thermal performance, and is IAQ friendly. The EcoShield liner offers an Environmental Protection Agency (EPA)-registered microbial mold and fungal inhibitor so it will not support bacteria. It contains no harmful irritants or chemicals and is safe for people and the environment. The liner complies with the American Society for Testing and Materials (ASTM) and the National Fire Protection Agency (NFPA) standards. The liners come in a variety of stock and custom sizes. They also offer high air-erosion tolerance and meet the same ASTM C1071 standards as fiberglass, the company said. EcoShield is resistant to dirt, debris, damage, and moisture, and does not itch or cause skin irritation.