Diisononyl adipate

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

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:

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.
For details see QMRF and QPRF inserted in "Overall remarks" and executive summary", respectively.

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:

no

Type of method:

other: calculation

Media:

soil

Test temperature:

25 °C

Key result

Type:

log Koc

Value:

5.15

Temp.:

25 °C

Remarks on result:

other: The substance is within the applicability domain of the model.

Type:

Koc

Value:

140 800

Temp.:

25 °C

Remarks on result:

other: The substance is within the applicability domain of the model.

Koc Estimate from MCI:

---------------------

First Order Molecular Connectivity Index ........... : 13.702

Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 7.7426

Fragment Correction(s):

2  Ester (-C-CO-O-C-) or (HCO-O-C) ...... : -2.5939

Corrected Log Koc .................................. : 5.1487

 

Estimated Koc: 1.408e+005 L/kg  <===========

Executive summary:

QPRF: KOCWIN v2.00 (18 Nov. 2013)

 

1.	Substance	See “Test material identity”
2.	General information
2.1	Date of QPRF	See “Data Source (Reference)”
2.2	QPRF author and contact details	See “Data Source (Reference)”
3.	Prediction
3.1	Endpoint (OECD Principle 1)	Endpoint	Adsorption to solid phase of soils etc.
		Dependent variable	Organic carbon normalised adsorption coefficient (Koc)
3.2	Algorithm (OECD Principle 2)	Model or submodel name	KOCWIN
		Model version	v. 2.00
		Reference to QMRF	QMRF: Estimation of Soil Adsorption Coefficient using KOCWIN v2.00 (EPI Suite v4.11): MCI methodology
		Predicted value (model result)	See “Results and discussion”
		Input for prediction	- Chemical structure via CAS number or SMILES
		Descriptor values	- MCI (first order molecular connectivity index) - Correction factors
3.3	Applicability domain (OECD principle 3)	Domains:
		1) Molecular weight (range of test data set: 32.04 to 665.02 g/mol; On-Line KOCWIN User’s Guide, Ch. 6.2.4 Domain)	Substance within range (398.63 g/mol)
		2) Correction factors: Number of instances of the identified correction factor does not exceed the maximum number as listed in Appendix D (On-Line KOCWIN User’s Guide)	fulfilled.
3.4	The uncertainty of the prediction (OECD principle 4)	Statistical accuracy for training dataset: n = 516, r² = 0.916, std. dev. = 0.330, average dev. = 0.263
3.5	The chemical mechanisms according to the model underpinning the predicted result (OECD principle 5)	Adsorption is caused by temporary (reversible) or permanent bonding between the substance and a surface (e.g. due to van der Waals interactions, hydrogen bonding to hydroxyl groups, ionic interactions, covalent bonding, etc.). The organic carbon normalized adsorption coefficient (Koc) is the ratio of a substance concentration sorbed in the organic matter component of soil or sediment to that in the aqueous phase at equilibrium. MCI methodology: The first-order molecular connectivity index is a measure to describe a variety of properties of chemicals. According to Sabljic (1984; cited in Meylan et al., 1992), the soil sorption potential is highly correlated with the first order MCI. Therefore, it has been used to derive the adsorption coefficient.

 

References

- US EPA (2012). On-Line KOCWIN User’s Guide.

- Meylan, W., P.H. Howard and R.S. Boethling. 1992. Molecular topology/fragment contribution method for predicting soil sorption coefficients. Environ. Sci. Technol. 26: 1560-1567.

 

 

Assessment of estimation domain (molecular weight, fragments, correction factors):

 

Model:	KOCWIN v2.00	MCI & Log Kow method
Substance:	DINA
CAS-#:	33703-08-1
SMILES:	O=C(OCCCCCCCCC)CCCCC(=O)OCCCCCCCCC
Molecular weight (g/mol):	398,63
Log Kow (experimental data):	924	Reference:	EPISUITE - KOWWIN data base match
	Molecular weight (g/mol)				log Kow
	Minimum	Maximum	Average		Minimum	Maximum
Training set	32,04	665,02	224,4		-2,11	8,12
Validation set	73,14	504,12	277,8		-5,98	8,68
Assessment of molecular weight	Molecular weight within range of training and validation set.
Assessment of log Kow (only relevant for log Kow method)	Log Kow outside of range of training and validation set. Therefore, the estimate may be less accurate.
Appendix D. MCI & Log Kow Correction Factors for 447 Compound Training Set
Correction Factor Descriptor	Coefficient for Molecular Connectivity Index (MCI) Regression Methodology		Coefficient for log Kow Regression Methodology	Occurrence		No. of instances of each bond found for the current substance
	(new model)	Remark		(number of compounds	(max per structure)
Ester (-C-CO-O-C-) or (HCO-O-C)	-1,296957	(a)	-0,065594	50	2	2
						.

Description of key information

Adsorption of Diisononyl adipate to solid soil is expected.

Key value for chemical safety assessment

Koc at 20 °C:

140 800

Additional information

No studies investigating the adsorption/desorption behaviour of Diisononyl adipate (CAS 33703-08-1) are available. Using KOCWIN Program (v2.00), a log Koc value of 5.15 was calculated based on the molecular conductivity index (MCI). The result of the QSAR calculation is considered appropriate since Diisononyl adipate falls within the applicability domain of the QSAR model. Based on this information adsorption of Diisononyl adipate to solid soil is expected.