1. The outer package of food plastic packaging bags should be marked with the name and the site of the factory, the product name, and the words "for food" in clear position in Chinese. The products should all be attached with inspection certificate when out of the factory. 

2. The food plastic packaging bags are odorless when out of the factory, and if they have any odors, they cannot be used as food packing bags. 

3. The plastic packing bags with colors (dark red or black bags are usually used in current market) cannot be used for food packing. Because such plastic packaging bags are often produced for recycling plastics. 

4. Do not choose material with coating and cladding material as far as possible. In modern packaging design, a large number of additional cladding materials are used in order to make the packaging more beautiful and corrosion resistant. Not only this has brought difficulties to the recycling and reuse of materials after the products are scrapped, but also most of the coatings themselves are toxic.