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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Adsorption / desorption

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Administrative data

Link to relevant study record(s)

adsorption / desorption: screening
Type of information:
Adequacy of study:
key study
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification
Justification for type of information:
QMRF and QPRF are attached.
Principles of method if other than guideline:
Calculation based on KOCWIN v2.00, Estimation Programs Interface Suite™ for Microsoft® Windows v 4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.
GLP compliance:
Type of method:
other: calculation
Test temperature:
25 °C
Key result
1 398
25 °C
Remarks on result:
other: MCI method; The substance is within the applicability domain of the model.
Key result
log Koc
25 °C
Remarks on result:
other: MCI method; the substance is within the applicability domain of the model.

KOCWIN Program (v2.00) Results:



CHEM  : Phosphoric acid, tris(2-methylpropyl) ester

MOL FOR: C12 H27 O4 P1

MOL WT : 266.32

--------------------------- KOCWIN v2.00 Results ---------------------------


Koc Estimate from MCI:


First Order Molecular Connectivity Index ........... : 7.750

Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 4.6396

Fragment Correction(s):

*  OrganoPhosphorus [P=O], aliphatic ..... : -1.4940

Corrected Log Koc .................................. : 3.1457


Estimated Koc: 1398 L/kg 

Description of key information

Adsorption of Triisobutyl phosphate to soil/sediment is expected.

Key value for chemical safety assessment

Koc at 20 °C:
1 398

Additional information

No studies investigating the adsorption/desorption behaviour of Triisobutyl phosphate (CAS 126-71-6) are available. Using KOCWIN Program (v2.00), a log Koc value of 3.14 was calculated based on the molecular conductivity index (MCI). The result of the QSAR calculation is considered appropriate as the substance is within the applicability domain of the QSAR model. Based on this information adsorption of triisobutyl phosphate to solid soil is expected.