CertainTeed Corp. has reformulated its ToughGard R duct liner by adding 25% recycled content. Composed of rotary-type glass fibers, ToughGard R duct liner is primarily used as an acoustical liner in HVAC duct systems. It also helps fight moisture and mold growth and improves the energy efficiency in heating and cooling systems. The product has a durable airstream surface and moisture protection. The airstream surface contains an EPA-registered antimicrobial agent, and provides exceptional resistance to tearing, puncturing and surface wear during installation and cleaning.