Sustainable Insulation is a fiberglass insulation manufactured with renewable and recycled content, including an organic, plant-based binder. Sustainable Insulation is designed to offer excellent acoustical performance and thermal properties. The product exceeds stringent CARB indoor air quality regulations and is GREENGUARD Children & Schools certified. In addition to sand, Sustainable Insulation fibers consist of a 50 percent renewable content and a recycled glass content of 35 or 70 percent. www.certainteed.com