The compostability of denim fabrics dyed with various indigos

Denim fabric samples representing current indigo dye sources and fabric structures were biodegraded in feedstock including food waste, manure, and animal bedding, which are typically composted at the Cornell Farm Services Composting Facility and processed under laboratory conditions for 77 days. Indigo types including dry denim, pre-reduced, and natural did not inhibit degradation as compared to undyed 100% cotton fabric. Additionally, fabrics tested as received from the mill and those tested post scouring degraded effectively. As expected, denim containing 24% polyester and 2% spandex retained overall fabric structure despite degradation of the cotton portion of the yarns.