BioBag Dog Waste Bags do not contain any polyethylene-based ingredients; they are 100% biodegradable plastic bags and 100% compostable plastic bags. As natural as dog waste and decompose within 40 days in a well-functioning composting environment, these dog poop bags are a great alternative to normal plastic bags that take more than 100 years to decompose. Bags measure 300mm x 200mm/ 50 bags per box.