Testing the bio-based content in a material to make trustable claims
November 5, 2012
– A famous mineral water company launched in 2011 a bottle made of 20% bio-based PET. This ratio has immediately been questioned by journalists, who did a test with ASTM D-6866 and obtained a 10-13% ratio of bio-based material.
This standard evaluates the content of Carbon-14 in materials. If a product is made of 100% fossil materials, there is no C-14. If it is 100% bio-based, the concentration of C-14 is equal to the atmospheric concentration. It enables the calculation of the bio-based carbon ratio in the product.
But organic materials include other elements, like oxygen, nitrogen or hydrogen. Their concentration may vary depending on the material. To improve the accuracy, the CEN/TC 411 is developing a standard based on a work done by SGS and the ACDV (the “bio-based” Chemistry Association). With it, the claim of 20% of bio-based plastics in the bottle would have been verified.
Referring to a given standard or a test method on the packaging/internet website would have avoided such a controversy. It is a general recommendation, as environmental claims are facing the distrust of consumers who are concerned with green washing.