ISO 17505:2025
(Main)Soil and waste characterization — Temperature dependent differentiation of total carbon (TOC400, ROC, TIC900)
Soil and waste characterization — Temperature dependent differentiation of total carbon (TOC400, ROC, TIC900)
This document specifies a method for the differentiated determination of the organic carbon content (TOC400) which is released at temperatures up to 400 °C, the residual oxidizable carbon (ROC) (including e.g. lignite (brown coal), hard coal, charcoal, black carbon, soot) and the inorganic carbon (TIC900) which is released at temperatures up to 900 °C. The basis of this method is the dry combustion or decomposition of carbon to CO2 in the presence of oxygen or non-oxygen conditions using temperatures ranging from 150 °C to 900 °C in dry solid samples of sediment, soil, soil with anthropogenic admixtures and solid waste (see Table 1) with carbon contents of more than 1 g per kg (0,1 % C) (per carbon type in the test portion). NOTE TIC900’ includes the TIC measured after acid addition e.g. by ISO 10694 or EN 15936. TOC400 is a fraction of TOC measured according to e.g. ISO 10694 or EN 15936.
Caractérisation des sols et des déchets — Différenciation en fonction de la température du carbone total (COT400, COR, CIT900)
General Information
Standards Content (Sample)
International
Standard
ISO 17505
First edition
Soil and waste characterization —
2025-06
Temperature dependent
differentiation of total carbon
(TOC , ROC, TIC )
400 900
Caractérisation des sols et des déchets — Différenciation en
fonction de la température du carbone total (COT , COR, CIT )
400 900
Reference number
© ISO 2025
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Interferences . 3
5.1 Interference due to carbides .3
5.2 Interference due to sulfur and nitrogen compounds .3
5.3 Interference due to carbonates .3
5.4 Peak not reaching the baseline .5
5.5 Difficulties in separating ROC peak and TIC peak .6
600 900A
5.6 Interferences due to premature releases and deflagrations .7
5.7 Interferences due to catalytic active substances in samples .7
6 Reagents . 7
6.1 General .7
6.2 Standards for system control .8
7 Apparatus . 8
8 Procedure . 9
8.1 General .9
8.2 Sample preparation and processing .9
8.3 Calibration .9
8.4 Measurement (oxidative method A) .9
8.5 Measurement (mixed oxidative/non-oxidative method B) .10
9 Evaluation .11
9.1 General .11
9.2 Control measurements . 13
10 Expression of results .13
11 Test report .13
Annex A (informative) Performance characteristics . 14
Annex B (informative) Cooling procedure for method B .21
Bibliography .22
iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
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This document was prepared by the European Committee for Standardization (CEN) (as EN 17505:2023)
and was adopted, without modifications other than those given below, by Technical Committee ISO/TC 190,
Soil quality, Subcommittee SC 3, Chemical and physical characterization under the fast-track procedure.
— EN ISO 10693 references have been changed to ISO 10693;
— EN 15936 has been added to the Bibliography;
— cross references in 6.2 have been corrected.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
Introduction
Carbon occurs in soils and materials similar to soil in a variety of compounds and forms. When determining
carbon in soils or soil-like materials, an overall determination of the different mass fractions is most
feasible. The summarized declaration of carbon is yet done by differentiating organic and inorganic carbon
(EN 15936, ISO 10694). In the proportion classified as “organic carbon”, a fraction of very stable highly
aromatic and highly condensed carbon compounds can be present, sometimes in significant mass fractions.
Since this black (pyrogenic) carbon is only very slowly decomposed and released, its environmental
relevance has to be differently evaluated than the proportions of organic carbon which are faster chemical-
biologically decomposed. The environmental relevance is estimated if e.g. the suitability of soils and soil-
like materials for disposal in landfill is assessed. For a differentiated assessment, a separate declaration
of the different mass fractions of organic, black (pyrogenic) and inorganic carbon is necessary. Using the
specified temperature-gradient method and utilizing the combustion characteristic(s), the carbon fractions
established according to this standard in soil and soil-like materials can be differentiated.
In respect of the hazard potential, the content of solely organically bonded carbon in solids determined with
the described method can be important for disposal and/or recycling.
The method has been validated with the materials listed in Table 1, see also Annex A.
Table 1 — Materials used for validation
Material type Materials used for validation
soils from natural material mineral soils
soil with anthropogenic admixtures (urban soils)
tailing material (tailings) tailing material from coal mining
sediment sediment
waste waste incineration ash
foundry sand
construction waste
v
International Standard ISO 17505:2025(en)
Soil and waste characterization — Temperature dependent
differentiation of total carbon (TOC , ROC, TIC )
400 900
1 Scope
This document specifies a method for the differentiated determination of the organic carbon content
(TOC ) which is released at temperatures up to 400 °C, the residual oxidizable carbon (ROC) (including
e.g. lignite (brown coal), hard coal, charcoal, black carbon, soot) and the inorganic carbon (TIC ) which is
released at temperatures up to 900 °C.
The basis of this method is the dry combustion or decomposition of carbon to CO in the presence of oxygen
or non-oxygen conditions using temperatures ranging from 150 °C to 900 °C in dry solid samples of sediment,
soil, soil with anthropogenic admixtures and solid waste (see Table 1) with carbon contents of more than 1 g
per kg (0,1 % C) (per carbon type in the test portion).
NOTE TIC includes the TIC measured after acid addition e.g. by ISO 10694 or EN 15936. TOC is a fraction of
900’ 400
TOC measured according to e.g. ISO 10694 or EN 15936.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
EN 16179, Sludge, treated biowaste and soil — Guidance for sample pretreatment
EN 15002, Characterization of waste — Preparation of test portions from the laboratory sample
ISO 11464, Soil quality — Pretreatment of samples for physico-chemical analysis
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
total organic carbon which is released up to 400 °C
TOC
quantity of carbon which is determined in the range
...
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