These bags are plastic free, made of certified veggie based materials and leak-proof bags. They come with the added bonus of being formulated for accelerated breakdown in 2-3 months and quickly turns waste into eco-friendly compost. It meets the guidelines of ASTM D6400. This is for the super pet parents who are environmentally conscious and are looking for something that can be tossed in their municipal compost bins. (Please check for your local compost guidelines, as some do not allow dog waste in compost bins)