The main cause of food spoilage are ethylene gas, ammonia gas, oxygen, hydrogen sulfide, humidity and temperture. A ZipFresh bag is composed of 3 unique layers.  The innermost layer is a patented film that slows the process of ripening by adsorping the harmful rotten gas and control humidity.  The second layer is LDPE to improve elastic strength.  The third layer is Nylon to handle extreme temperatures and provide complete oxygen shutoff.