Understanding Biobased Content
- A product’s biobased content depends on its total organic carbon content and not on its weight according to ASTM D6866
- The terms biobased and non-biobased are applicable to carbon-containing products
- ASTM D6866 is able to distinguish biobased from non-biobased products
Here are some definitions to clarify the concepts:
BIOBASED – Materials that are derived in whole or in part from biomass resources are biobased. Biomass resources are organic materials that are available on a renewable or recurring basis such as crop residues, wood residues, grasses, and aquatic plants. Corn ethanol is a well-known example of a biobased material derived from biomass resources.
BIOBASED PRODUCT – Any product that contains some amount of biobased material within it is technically a biobased product. The term is typically applied only to materials containing carbon.
NON-BIOBASED PRODUCT - Any product that does not contain any biobased materials in it is a non-biobased product, but the term is typically applied only to materials containing carbon. Products made entirely from petrochemical resources are referred to as non-biobased products. Glass, however, is not generally referred to as non-biobased material since it doesn't contain any carbon.
PERCENT BIOBASED CONTENT ("percent biobased" or "biobased content") – This is the amount of carbon in a product that is derived from biobased materials relative to the total amount of carbon in the entire product.
The emerging biobased manufacturing industry is producing large quantities of products that contain mixtures of both biobased materials and petroleum-derived materials. "Percent biobased" is a measure of the amount of biobased carbon in the product as compared to the sum of biobased and petroleum-based carbon in the product. A percent biobased value of 75% would mean that of all the carbon in the product, 75% of it is biobased and 25% is petroleum based.1
The purpose of a biobased content measurement is to determine how much of the carbon within a biobased product is derived from biobased materials. The value represents a measure of how much biobased material a company is using to manufacture its products relative to the more readily available and less expensive petroleum-based alternatives.
Biobased Content Determination via ASTM D6866
Through radiocarbon dating techniques, ASTM D6866 can measure the exact percentage of a material that came from renewable sources. It must be noted though that a product’s biobased content is based ONLY on the organic (carbon-containing) fraction of the formulation. To illustrate, here are some hypothetical formulations:
(1) Product A Formulation – 75% biobased material and 25% water
Product A biobased content = 100% (the 75% organic fraction is 100% biobased)
(2) Product B Formulation – 50% biobased material, 25% petroleum-based, 25% water
Product B biobased content = 66.7% (the product is 75% organic but only 50% of that fraction is biobased while 33.3% is petroleum-based)
(3) Product C Formulation – 25% glass and 70% polypropylene
Product C biobased content = 0% (glass is inorganic and polypropylene is a petroleum derivative)
(4) Product D Formulation – 50% biobased material, 25% petroleum-based, 20% water, 5% additives that are also biobased
Product D biobased content = 68.75% (total biobased content of the product is 55% against total organic fraction of 80%)
1. Schonhofer, Franze. 14C in Austrian Wine and Vinegar. RADIOCARBON, VOL. 34, No. 3, 1992, P. 768-7711.
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