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Adsorption / desorption

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adsorption / desorption: screening
Type of information:
Adequacy of study:
key study
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Calculation of the log Koc to determine the potential for adsorption/desorption of chemicals is acceptable provided that a recognised and scientifically robust methos is used. The TGD includes a method for calculating a log Koc QSAR using the log Kow. This approach is considered to be acceptable with restrictions.
Justification for type of information:
A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.
Reason / purpose for cross-reference:
read-across: supporting information
Principles of method if other than guideline:
Calculated from Log Kow 4 and the TGD calculation of Koc = 0.81.Log Kow + 0.1.
GLP compliance:
Not applicable
Type of method:
other: QSAR
other: Not applicable
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
Not reported
Test temperature:
Not reported
Details on study design: HPLC method:
Not reported
Details on sampling:
Not reported
Details on matrix:
Not reported
Details on test conditions:
Not reported
Computational methods:
Not reported
Key result
2 187.76
Remarks on result:
other: Temperature and pH not specified
Key result
log Koc
Remarks on result:
other: Temperature and pH
Details on results (HPLC method):
Not reported
Adsorption and desorption constants:
Not reported
Recovery of test material:
Not reported
Concentration of test substance at end of adsorption equilibration period:
Not reported
Concentration of test substance at end of desorption equilibration period:
Not reported
Details on results (Batch equilibrium method):
Not reported
Not reported
Validity criteria fulfilled:
not applicable
Not applicable for QSARs
N-hexane has a log Koc of 3.34.
Executive summary:

The Koc of N-hexane was calculated from Log Kow 4 using the TGD calculation of Koc = 0.81 . Log Kow + 0.1. The log koc of n-hexane is 3.34 and Koc of 2187.76. This calculation is considered reliable for assessment for the adsorption of hexane.

Description of key information

Adsorption / Desorption:

There is no data available for Methylcyclopentane. Based on a category-approach data are read-across to n-Hexane.


The log Koc of n-hexane was calculated to be 3.34.


Key value for chemical safety assessment

Koc at 20 °C:
2 187.76

Additional information

There is no data available for Methylcyclopentane. Data are read-across to structural analogue n-Hexane.

As the log Kow of methylcycopentane is >3 based on read across data, the adsorption/desorption endpoint cannot be waived. However, ECHA's Guidance on Information Requirements and Chemical Safety Assessment R7a Endpoint Specific Guidance (2008) indicates that before commissioning a new study alternative sources of data (e.g. QSAR) on the adsorption/desorption potential of a chemical should be used. The log Koc of n-hexane was calculated to be 3.34. This has been read across to methylcyclopentane.

[LogKoc: 3.34]