Bis(methylcyclohexyl) phthalate

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:

QMRF and QPRF are presented in "overall remarks" and "executive summary", respectively.

Principles of method if other than guideline:

Calculation based on KOCWIN v2.00 estimation using first-order Molecular Connectivity Index (MCI), 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: QSAR calculation

Specific details on test material used for the study:

- Name of test material (as cited in study report): 1,2-Benzenedicarboxylic acid, bis(methylcyclohexyl) ester
- Molecular formula (if other than submission substance): C22H30O4
- Molecular weight (if other than submission substance): 358.48
- Smiles notation (if other than submission substance): C1CC(C)CCC1OC(=O)c2ccccc2C(=O)OC3CCC(C)CC3
- Analytical purity: not applicable

Test temperature:

25 °C

Key result

Type:

Koc

Value:

34 290

Temp.:

25 °C

Remarks on result:

other:

Remarks:

The substance is within the applicability domain of the model.

Key result

Type:

log Koc

Value:

4.54

Temp.:

25 °C

Remarks on result:

other:

Remarks:

The substance is within the applicability domain of the model.

KOCWIN Program (v2.00) Results:

==============================

SMILES : C1CC(C)CCC1OC(=O)c2ccccc2C(=O)OC3CCC(C)CC3

CHEM  : 1,2-Benzenedicarboxylic acid, bis(methylcyclohexyl) ester

MOL FOR: C22 H30 O4

MOL WT : 358.48

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

 

Koc Estimate from MCI:

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

First Order Molecular Connectivity Index ........... : 12.525

Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 7.1290

Fragment Correction(s):

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

Corrected Log Koc .................................. : 4.5351

 

Estimated Koc: 3.429e+004 L/kg  <===========

Executive summary:

QPRF: KOCWIN v2.00 (16 Jan 2017)

 

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)	Substancewithin range (358.48 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:	1,2-Benzenedicarboxylic acid, bis(methylcyclohexyl) ester
CAS-#:	27987-25-3
SMILES:	C1CC(C)CCC1OC(=O)c2ccccc2C(=O)OC3CCC(C)CC3
Molecular weight (g/mol):	358,48
Log Kow (experimental data):	7,04	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 within range of training and validation set.
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 to solid soil phase is expected (log Koc = 4.54, KOCWIN v2.00).

Key value for chemical safety assessment

Koc at 20 °C:

4.54

Additional information

No experimental study investigating the adsorption potential of Bis(methylcyclohexyl) phthalate (CAS 27987-25-3) is available. In Article 13 of Regulation (EC) No 1907/2006, it is laid down that information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI (of the same Regulation) are met. According to Annex XI of Regulation (EC) No 1907/2006 (Q)SAR results can be used if (1) the scientific validity of the (Q)SAR model has been established, (2) the substance falls within the applicability domain of the (Q)SAR model, (3) the results are adequate for the purpose of classification and labeling and/or risk assessment and (4) adequate and reliable documentation of the applied method is provided. For the assessment of Bis(methylcyclohexyl) phthalate (Q)SAR results were used. The criteria listed in Annex XI of Regulation (EC) No 1907/2006 are considered to be adequately fulfilled and therefore the endpoint(s) sufficiently covered and suitable for risk assessment. Hence, further experimental studies assessing the adsorption potential of Hydrocarbons, C11-C13 (odd numbered), n-alkanes, <2% aromatics are not considered to be needed.

 

[LogKoc: 34290.0]