4-hydroxybutyl acrylate

Adsorption / desorption

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

adsorption / desorption: screening

Type of information:

(Q)SAR

Adequacy of study:

supporting 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: see 'Overall remarks, attachments'.
- QPRF: see 'Executive summary'.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Calculation using KOCWIN (v2.00) log Kow Method

GLP compliance:

no

Type of method:

other: QSAR estimation: KOCWIN v2.00: Koc estimate from log Kow

Specific details on test material used for the study:

- SMILES Code: O=C(OCCCCO)C=C

Test temperature:

25 °C

Computational methods:

log Kow used for estimation: 0.77 (user entered data).

Type:

Koc

Value:

7.481 L/kg

Temp.:

25 °C

Type:

log Koc

Value:

0.874 dimensionless

Temp.:

25 °C

Koc Estimate from Log Kow:

Log Kow (User entered )	0.77
Non-Corrected Log Koc (0.55313 logKow + 0.9251)	1.3510
Fragment Correction(s):
Aliphatic Alcohol (-C-OH)	-0.4114
Ester (-C-CO-O-C-) or (HCO-O-C)	-0.0656
Corrected Log Koc	0.8740
Estimated Koc	7.481 L/kg

Executive summary:

QPRF: KOCWIN v2.00 (using log Kow method) (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): Estimation using log Kow
		Predicted value (model result)	See “Results and discussion”
		Input for prediction	- Chemical structure via CAS number or SMILES - log Kow (for log Kow method; optional)
		Descriptor values	- Chemical structure - 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 (144.17 g/mol)
		2) log Kow (range of test data set: -2.11 to 8.12; On-Line KOCWIN User’s Guide, Appendices E & F)	Substance within range (0.77)
		3) 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)	Nonpolar compounds: n = 68; r^2=0.478, average dev. = 0.371 Polar compounds: n = 447, r²=0.855, std. dev.= 0.396, average dev. = 0.307
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. Estimation using log Kow: The model is based on the high correlation of log Kow and the adsorption potential.

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):

Training set: Molecular weights	Training set	Validation set
Minimum	32.04	73.14
Maximum	665.02	504.12
Average	224.4	277.8
Assessment of molecular weight	Molecular weight within range of training and validation set
Training set: Log Kow	Training set	Validation set
Minimum	-2.11	-5.98
Maximum	8.12	8.68
Assessment of log Kow	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 log Kow Regression Methodology	Occurrence		No. of instances of each bond found for the current substance
		(number of compounds	(max. per structure)
Aliphatic Alcohol (-C-OH)	-0.411443	21	1	1
Ester (-C-CO-O-C-) or (HCO-O-C)	-0.065594	50	2	1

Reference 2

Endpoint:

adsorption / desorption: screening

Type of information:

(Q)SAR

Adequacy of study:

supporting 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: see 'Overall remarks, attachments'.
- QPRF: see 'Executive summary'.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Calculation using KOCWIN (v2.00) Molecular Connectivity Index (MCI)

GLP compliance:

no

Type of method:

other: QSAR estimation: KOCWIN v2.00: Koc estimate from MCI

Specific details on test material used for the study:

- SMILES Code: O=C(OCCCCO)C=C

Test temperature:

25 °C

Type:

Koc

Value:

10 L/kg

Temp.:

25 °C

Type:

log Koc

Value:

1 dimensionless

Temp.:

25 °C

Koc Estimate from MCI:

First Order Molecular Connectivity Index	4.808
Non-Corrected Log Koc (0.5213 MCI + 0.60)	3.1062
Fragment Correction(s):
Aliphatic Alcohol (-C-OH)	-1.3179
Ester (-C-CO-O-C-) or (HCO-O-C)	-1.2970
Corrected Log Koc	0.4914
Over Correction Adjustment to Lower Limit Log Koc	1.000
Estimated Koc	10 L/kg

Executive summary:

QPRF: KOCWIN v2.00 (MCI methodology) (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 (144.17 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):  

Training set: Molecular weights	Training set	Validation set
Minimum	32.04	73.14
Maximum	665.02	504.12
Average	224.4	277.8
Assessment of molecular weight	Molecular weight 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		Occurrence		No. of instances of each bond found for the current substance
	(new model)	Remark	(number of compounds	(max. per structure)
Aliphatic Alcohol (-C-OH)	-1.317914	(a)	21	1	1
Ester (-C-CO-O-C-) or (HCO-O-C)	-1.296957	(a)	50	2	1

(a) Counted up to twice per structure, regardless of number of occurrences.

Description of key information

Testing is not required, as 4-hydroxybutyl acrylate is readily biodegradable. Furthermore, the test substance has a low potential for adsorption based on its measured log Pow of 0.77. For 4-hydroxybutyl acrylate Koc values were calculated to be 10 L/kg (log Koc = 1.0) and 7.481 L/kg (log Koc = 0.8740) when based on the MCI method and the log Kow method, respectively. Based on a log Koc of <3 adsorption to solid soil phase is not expected.

Key value for chemical safety assessment

Koc at 20 °C:

10

Additional information

QSAR-disclaimer:

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 4-hydroxybutyl acrylate (Q)SAR results were used for adsorption / desorption. 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.

[LogKoc: 1.0]