Frequently Asked Questions

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About ASTM D6866 Method

The sampling is done onsite, but the analysis is done offsite in a radiocarbon dating lab.

A material’s renewable carbon content (carbon from recently expired matter) is correlated to its carbon 14 content. Matter that came from renewable sources still has carbon 14 whereas those from fossil sources have no carbon 14 left. Through radiocarbon dating, the amount of carbon 14 is known. It is the preferred method because it has the technology to measure the quantity of carbon 14 present.

Most radiocarbon dating labs do “their own thing” and have their own reporting formats. University labs have limited manpower and may not have the experience in the sample treatment and calculations for ASTM D6866. Commercial radiocarbon dating labs, on the other hand, have the manpower and technical expertise to provide reliable results.

Beta Analytic has an edge over other radiocarbon dating labs because it has contributed to the development of the method—-and therefore has a thorough understanding of it—-and it is accredited to ISO/IEC 17025:2005, an accreditation required by most regulators.

The ASTM D6866 or EN 15440 result mean that 60% of the carbon “in” the combusted mass was from renewable sources, NOT 60% “of” the combusted mass was renewable material.

The variability is not accounted for by ASTM D6866 but by the sampling method ASTM D7459. Given that the feedstock proportions will continually change, continuous collection of CO2 (via a controlled flow meter at the exit of a CEMS or stack probe) will give the true running average for a specific collection period (e.g. 1 week, 1 month).

Please refer to the report commissioned by the UK Renewable Energy Association and Columbia University, which goes into detail on how to calculate the energy content. Click here to download the document.

ASTM D6866 is more flexible in terms of applicable samples. It can be used for solid, liquid, and gas samples. EN 15440 is only applicable to solid recovered fuels and is used only in Europe.

The ratio between carbon 14 in a sample and the carbon 14 in a modern reference standard is reported as pMC or percent modern carbon. Through experiments, it is known that materials with 100% present-day carbon have a radiocarbon signature near 105 pMC; this value is set to be 100% renewable content. Materials that are from fossil sources, on the other hand, have 0 pMC and 0% renewable content. Materials with both fossil and present-day carbon will have pMC values greater than zero but lesser than 105.

About Samples for Submission

As stated in the EUETS 2007 FAQ, the minimum analysis frequency for solid waste (pure fossil or mixed biomass & fossil) is every 5,000 tons and at least 4 times a year.

Yes, the California AB32 program allows solid fuel sampling in lieu of emissions sampling. Details are found on page 19 of the AB32 FAQ found here.

No. Sorted or not, the materials will still have the same renewable content. One of the advantages of using the ASTM D6866 result is that you do not need to know the tonnage factor (i.e. the weighing and sorting of all the material). Whether you burn 1 ton or 20 tons of sample, the ASTM D6866 result would still be the same.

If you know the tonnage CO2 produced and the biomass content from the ASTM D6866 result, you can calculate exactly how much “renewable” carbon contributed to the energy production. This is necessary in certain initiatives like the UK Renewable Obligation Program.

For gas samples, 1 liter is sufficient for testing if the gas collected is not diluted. If the sample is diluted, send five liters of gas. The gas sample should be collected according to the ASTM D7459 standard.

For solid samples like RDF, SRF, tires, waste, and sludge, a minimum of 5 grams is sufficient (25 grams max).

Gas samples should be sent in a gas bag. Solid samples can be placed in any container that can be sealed tightly.

Please send your samples to Beta Analytic’s London office at this address:

Beta Analytic Limited
London BioScience Innovation Centre
2 Royal College Street
London NW10NH
United Kingdom

If you are in Japan, please send your samples to our Japanese agent in Nagoya at the address below. If you are in China, send your samples to our Beijing facility. For other Asian countries, send samples directly to the U.S. headquarters.


Japan Representative:
Chikyu Kagaku Kenkyusho Corp.
1-608 Ueda-Honmachi
Nagoya 468-0007

China Representative:

Beta Analytic Inc.
5/F South Block Tower C, Raycom InfoTech Park
No.2 KeXueYuan South Road, Haidian District,
Beijing 100190

U.S. Headquarters:
Beta Analytic Inc.
4985 SW 74 Court
Miami, Florida 33155

Please send your samples to Beta Analytic’s Miami lab.

Beta Analytic Inc.
4985 SW 74 Court
Miami, Florida 33155


Neutral carbon, renewable carbon, and green carbon all refer to carbon from biomass. They are also synonymous to biocarbon or biomass carbon. Fossil carbon, on the other hand, refers to carbon from fossil sources. Thus, carbon from burning plants would be called neutral carbon whereas carbon from burning coal or petroleum coke would be called fossil carbon.