Calculating and Reporting Biobased Carbon Contents

Percent biobased carbon content = mass of biobased (organic) carbon/total mass of (organic) carbon x 100. 

Inorganic carbon like calcium carbonate is excluded from the calculations and in the ASTM D6 8 66 method for measuring biobased carbon content, any carbonate present is removed before measuring the biobased carbon content. 

The percent biobased carbon content, using ASTM D6866, gives the ratio of the mass of biobased (organic) carbons to total mass of (organic) carbons present in the product, for example, if a product A has 60% biobased carbon content, it means that for every 100 kg of carbon present in product A there is 60 kg of biobased carbon. It is not that for every 100 kg of Product A, there is 60 kg of biobased carbon This is because product A includes elements other than carbon, like hydrogen, oxygen and other elements. 

This does not pose a problem, because there is a straightforward and well-established method in organic chemistry to experimentally determine the elemental analysis -which gives the percent of carbon present in the product. 

In the above example, let us assume that elemental analysis of Product A gives us 50% organic carbon, 5% hydrogen and 45% oxygen - in other words 100 kg of Product A contains 50 kg of carbon. 

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