These Hercules® Sustain Plant Based Storage Bags have been independently tested and certified by the USDA Biobased program to contain minimum 50% plastic made from ethanol derived from fast growing sugar cane. This has the double benefit of helping to reduce our reliance on fossil fuels and helping to remove CO² from the atmosphere during the rapid growth phase of the sugar cane. Hercules® Sustain Plant Based Storage Bags perform as well as regular resealable food bags with these added benefits to the environment.