China Biodegradable Vegetable and Fruits Bags 100% Compostable guarantee: 1. You can check the authenticity of our certificate number from the TUV institution. For the finished product, you can randomly pick several bags to make the "infrared spectrum" test. This test can be done by many testing companies within the price of 200 USD, the results will be finished within 5 days, compared with the spectrum on our certificate, when the curve is more than 95% identical, the same degradation product as the certificate can be determined. http://www.orizon-bio.com/biod....egradable-vegetable-