In accordance with this standard, we use radiocarbon dating (also known as carbon-14) using analytical testing techniques to determine the age of carbon-containing objects.
Please note that the bio-based content does not in any way define a product's environmental impact or sustainability. This impact can be measured using a life cycle analysis based on defined sustainability criteria.
Radiocarbon analysis of biobased products
Radiocarbon analysis of bio-based products must comply with the NF EN 16640 standard by using one of the three regulatory methods.
CIRAM laboratories explain AMS carbon-14 analysis in detail.
What is a biobased product?
The term biosourced means "derived from biomass". A biobased product can be entirely or partially derived from biomass. Thanks to our laboratory analyses, we can characterize the quantity of biomass contained in a product (paint, solvent polymers, etc.).
It will be interesting to measure the amount of bio-based carbon in an R&D phase, but also in a finished product (biogenic carbon in biofuels, biogas, smoke, but also in cosmetics and agri-food products) or to evaluate a supplier's raw materials. Carbon-14 measurement quantifies the biogenic and synthetic (petro-based) carbon content.
Carbon-14, an element present in all living organisms
The carbon 14 (¹⁴C) is an radioactive isotope of carbon resulting from the interaction between the nitrogen 14 atoms present in the atmosphere and the cosmic radiation. Unstable by nature, it gradually disintegrates to become nitrogen 14 again. Its half-life, estimated at 5,568 years, implies that its concentration halves over this period and that it almost completely disappears after about . Petroleum-based materials therefore no longer contain.
Due to its continuous regeneration by solar activity, the concentration of carbon 14 is considered almost constant in the atmosphere. It is thus present in all the living organisms, where it is assimilated by the photosynthesis and breathing. The current biomass (cereals, algae, wood, residues and organic waste) therefore possesses a carbon 14 reservoir called « modern » fully active.
Conversely, the after approximately such as the oil, gas or coal, derived from the transformation of organic matter on millions of years, no longer contain carbon 14. They are composed exclusively of old carbon or petroleum-sourced, which allows them to be clearly distinguished from sources bio-based.
By measuring the isotopic ratio between ¹⁴C, ¹³C, and ¹²C, scientists at the CIRAM supports precisely determine the content of modern (bio-based) and fossil (petro-based) carbon in a sample. This approach forms the basis ofradiocarbon analysis, which is used for the characterization of bio-based products, the control of raw materials and verification of environmental claims.
AMS radiocarbon analysis
The NF EN 16640 standard specifies three methods for measuring the carbon-14 content of bio-based products. CIRAM supports laboratories exclusively use accelerator mass spectrometry (AMS), a reference technique recognized for its high precision and sensitivity inradiocarbon analysis.
Before measurement by AMS, the sample is prepared by transforming it into pure carbonin the form of graphite, then compacted into a sample-holding cathode. This preparation step is essential to ensure the reliability of the results and the reproducibility of the measurements.
The carbon-14 content and is then expressed either in mass fraction of the sample, or in fraction of total carbon content. The modern carbon percentage, called pMC (percent Modern Carbon), corresponds to a value normalized and standardized carbon 14 measured. This value is compared to that of a reference material (REF), representing 100% bio-based carbon.
Since 2003dating, official reference values used in the context of the NF EN 16640 standard are published by theUniversity of Groningen, ensuring international consistency in the interpretation of resultscarbon-14 analysis.
To illustrate the evolution of these references, we can recall that:
- in 2022, the value corresponding to 100% bio-based carbon was set at 100 pMC;
- in 2010, the reference value for certifying 100% content was 104 pMC;
- In 1964, this value reached 190 pMC, due to the effects of atmospheric nuclear testing on carbon-14 concentrations.
The calculation method for biobased products
The NF EN 16640 standard specifies that, in addition to measuring the pMC, we must also indicate:
- XTC the total carbon content of the sample,
- Xb the biobased carbon content as a fraction of the sample mass.
Based on the REF reference value, we can calculate XTCB, which is the bio-based carbon content as a fraction of the total carbon content. This value is decisive.
Please note that the NF EN 16640 standard specifies that the measurement of bio-based carbon content using AMS radiocarbon dating has an uncertainty of ±2%. This means that the bio-based carbon content may vary by ±2%. In other words, an XTCB value of 98% may be considered as 100% bio-based carbon relative to total carbon, within the margin of uncertainty.
The NF EN 16640 standard does not recommend any particular treatment for materials containing inorganic carbonates. However, calcium carbonates contain "old carbon" and risk artificially lowering the value of XTCB. This clarification is important because it indicates that the NF standard 16640 defines the percentage of bio-based carbon compared to total carbon, unlike the ASTM D6866 standard who can consider the percentage of bio-based carbon compared to total organic carbon.
