Oligomerisation products of 2,2'-[(1-methylethylidene)bis(4,1-phenyleneoxymethylene)]bisoxirane with acrylic acid and lauric acid

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

2020

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

QSAR prediction from a well-known and acknowledged tool. See below under ‘attached background
material section’ for detailed results including domain evaluation.

Qualifier:

according to guideline

Guideline:

other: REACH guidance on QSARs: Chapter R.6. QSARs and grouping of chemicals

Principles of method if other than guideline:

Since the test substance is a UVCB, the aqueous hydrolysis rate constant values were estimated for the individual substances representative of the major components. The estimated base-catalysed rate constants are used to calculate hydrolysis half-lives at selected pHs.

Estimation method (if used):

HYDROWIN estimates acid- and base-catalyzed rate constants; with the the exception of phosphorus esters, it does NOT estimate neutral hydrolysis rate constants.  The estimated base-catalysed rate constants are used to calculate hydrolysis half-lives and selected pHs.

Since the test substance can be classified as an ester, HYDROWIN program estimated a base-catalyzed rate constant for individual constituents.

The following equation was used in the model:

log Kb  =  0.92Es{R1} + 0.31Es{R2} + 2.16 sigma*{R1} + 2.30 sigma*{R2} + 2.10 sigmaX{R1} + 1.25 sigmaX{R2} + 2.67

where Es is the steric factor at the designated position, sigma* is the Taft constant at the designated position, and sigmaX is the Hammett constant at the designated position.

The ester equation regression had the following statistics (Mill et al, 1987):

  number = 124

  correlation coeff (r) = 0.982

  correlation coeff (r2) = 0.965

HYDROWIN estimates a half-life based upon the total base- or acid-catalyzed rate constant.  When a compound contains more than one hydrolyzable group, individually estimated rate constants are summed to yield the total rate constant.  The half-life for base-catalyzed rate constants is calculated at pH 8 from the following equation:

 Half-life  =  0.6931 / (Kb)(1.0E-6)

where 1.0E-6 (or 0.000001) is the OH- concentration in water at pH 8.  A half-life at pH 7 is also reported.  The half-life for acid-catalysed rate constants is calculated at pH 7 where both the OH- and H+ concentrations are 1.0E-7.


Reference:

Mill, T., Haag, W., Penwell, P., Pettit, T. and Johnson, H.  1987.  Environmental Fate and Exposure Studies Development of a PC-SAR for Hydrolysis: Esters, Alkyl Halides and Epoxides.  EPA Contract No. 68-02-4254.  Menlo Park, CA: SRI International.

Transformation products:

not specified

pH:

8

Temp.:

25 °C

DT50:

> 74.38 - <= 328.76 d

Type:

(pseudo-)first order (= half-life)

pH:

7

Temp.:

25 °C

DT50:

> 2.036 - <= 9.001 yr

Type:

(pseudo-)first order (= half-life)

Details on results:

Identity, SMILES and representative structures of the major constituents of the substance are given below. These are used as inputs for the modelling.

SMILES : c1(C(C)(C)c2ccc(OCC(O)COC(=O)C=C)cc2)ccc(OCC(O)CO)cc1
CHEM : Mono-functionalised BADGE with acrylic acid
MOL FOR: C24 H30 O7
MOL WT : 430.50
--------------------------- HYDROWIN v2.00 Results ---------------------------
NOTE: Fragment(s) on this compound are NOT available from the fragment
library. Substitute(s) have been used!!! Substitute R1, R2, R3,
or R4 fragments are marked with double astericks "**".

ESTER: R1-C(=O)-O-R2 R1: -CH=CH2
** R2: -CH2-CH3
Kb hydrolysis at atom # 15: 2.440E-002 L/mol-sec

Total Kb for pH > 8 at 25 deg C : 2.440E-002 L/mol-sec
Kb Half-Life at pH 8: 328.762 days
Kb Half-Life at pH 7: 9.001 years


SMILES : c1(C(C)(C)c2ccc(OCC(O)COc3ccc(C(C)(C)c4ccc(OCC(O)COC(=O)CCCCCCCCCCC)c
c4)cc3)cc2)ccc(OCC(O)CO)cc1
CHEM : Mono-functionalised BADGE with lauric acid
MOL FOR: C51 H70 O10
MOL WT : 843.12
--------------------------- HYDROWIN v2.00 Results ---------------------------
NOTE: Fragment(s) on this compound are NOT available from the fragment
library. Substitute(s) have been used!!! Substitute R1, R2, R3,
or R4 fragments are marked with double astericks "**".

ESTER: R1-C(=O)-O-R2 ** R1: n-Octyl-
** R2: -CH2-CH3
Kb hydrolysis at atom # 32: 2.848E-002 L/mol-sec
Total Kb for pH > 8 at 25 deg C : 2.848E-002 L/mol-sec
Kb Half-Life at pH 8: 281.632 days
Kb Half-Life at pH 7: 7.711 years



SMILES : c1(C(C)(C)c2ccc(OCC(O)COC(=O)C=C)cc2)ccc(OCC(O)COC(=O)C=C)cc1
CHEM : Di-functionalised BADGE with acrylic acid
MOL FOR: C27 H32 O8
MOL WT : 484.55
--------------------------- HYDROWIN v2.00 Results ---------------------------
NOTE: Fragment(s) on this compound are NOT available from the fragment
library. Substitute(s) have been used!!! Substitute R1, R2, R3,
or R4 fragments are marked with double astericks "**".

ESTER: R1-C(=O)-O-R2 R1: -CH=CH2
** R2: -CH2-CH3
Kb hydrolysis at atom # 15: 2.440E-002 L/mol-sec

ESTER: R1-C(=O)-O-R2 R1: -CH=CH2
** R2: -CH2-CH3
Kb hydrolysis at atom # 30: 2.440E-002 L/mol-sec

Total Kb for pH > 8 at 25 deg C : 4.880E-002 L/mol-sec
Kb Half-Life at pH 8: 164.381 days
Kb Half-Life at pH 7: 4.501 years



 
SMILES : c1(C(C)(C)c2ccc(OCC(O)COC(=O)C=C)cc2)ccc(OCC(O)COC(=O)CCCCCCCCCCC)cc1
CHEM : Di-functionalised BADGE with lauric acid and acrylic acid
MOL FOR: C36 H52 O8
MOL WT : 612.81
--------------------------- HYDROWIN v2.00 Results ---------------------------
NOTE: Fragment(s) on this compound are NOT available from the fragment
library. Substitute(s) have been used!!! Substitute R1, R2, R3,
or R4 fragments are marked with double astericks "**".

ESTER: R1-C(=O)-O-R2 R1: -CH=CH2
** R2: -CH2-CH3
Kb hydrolysis at atom # 15: 2.440E-002 L/mol-sec

ESTER: R1-C(=O)-O-R2 ** R1: n-Octyl-
** R2: -CH2-CH3
Kb hydrolysis at atom # 30: 2.848E-002 L/mol-sec

Total Kb for pH > 8 at 25 deg C : 5.288E-002 L/mol-sec
Kb Half-Life at pH 8: 151.689 days
Kb Half-Life at pH 7: 4.153 years



SMILES : c1(C(C)(C)c2ccc(OCC(O)COC(=O)C=C)cc2)ccc(OCC(COC(=O)CCCCCCCCCCC)OC(=O
)CCCCCCCCCCC)cc1
CHEM : Tri-functionalised BADGE with mixed functional groups with lauric acid and acrylic acid
MOL FOR: C48 H74 O9
MOL WT : 795.12
--------------------------- HYDROWIN v2.00 Results ---------------------------
NOTE: Fragment(s) on this compound are NOT available from the fragment
library. Substitute(s) have been used!!! Substitute R1, R2, R3,
or R4 fragments are marked with double astericks "**".

ESTER: R1-C(=O)-O-R2 R1: -CH=CH2
** R2: -CH2-CH3
Kb hydrolysis at atom # 15: 2.440E-002 L/mol-sec

ESTER: R1-C(=O)-O-R2 ** R1: n-Octyl-
** R2: -CH2-CH2-O-CH3
Kb hydrolysis at atom # 29: 6.204E-002 L/mol-sec

ESTER: R1-C(=O)-O-R2 ** R1: n-Octyl-
** R2: iso-Propyl-
Kb hydrolysis at atom # 43: 2.141E-002 L/mol-sec

Total Kb for pH > 8 at 25 deg C : 1.079E-001 L/mol-sec
Kb Half-Life at pH 8: 74.378 days
Kb Half-Life at pH 7: 2.036 years


SMILES : c1(C(C)(C)c2c(OCC(O)COC(=O)C=C)ccc(C(C)(C)c3ccc(OCC(O)COC(=O)C=C)cc3)
c2)ccc(OCC(O)COC(=O)C=C)cc1
CHEM : Tri-functionalised BADGE with acrylic acid
MOL FOR: C42 H50 O12
MOL WT : 746.86
--------------------------- HYDROWIN v2.00 Results ---------------------------
NOTE: Fragment(s) on this compound are NOT available from the fragment
library. Substitute(s) have been used!!! Substitute R1, R2, R3,
or R4 fragments are marked with double astericks "**".

ESTER: R1-C(=O)-O-R2 R1: -CH=CH2
** R2: -CH2-CH3
Kb hydrolysis at atom # 13: 2.440E-002 L/mol-sec

ESTER: R1-C(=O)-O-R2 R1: -CH=CH2
** R2: -CH2-CH3
Kb hydrolysis at atom # 33: 2.440E-002 L/mol-sec

ESTER: R1-C(=O)-O-R2 R1: -CH=CH2
** R2: -CH2-CH3
Kb hydrolysis at atom # 49: 2.440E-002 L/mol-sec

Total Kb for pH > 8 at 25 deg C : 7.320E-002 L/mol-sec
Kb Half-Life at pH 8: 109.587 days
Kb Half-Life at pH 7: 3.000 years

Validity criteria fulfilled:

not applicable

Conclusions:

The half-life values for the constituents of test substance were from 74.38 to 328.76 days at pH 7 and from 2.036 to 9.001 year at pH 7 at 25 degree Celsius. This indicates that the test substance is considered to be persistent at environmentally relevant pHs.

Executive summary:

The hydrolysis rate constants and half-life values of the test substance was estimated using the HYDROWIN v2.0 program (EPI SuiteTM v4.11). Since the test substance is a UVCB with similar constituents varying mainly in carbon chain lengths, the half-life values were estimated for the individual components at pH 7 and pH 8. SMILES codes were used as the input parameter for the BCF value estimation for the individual constituents. The half-life values for the constituents of test substance were from 74.38 to 328.76 days at pH 7 and from 2.036 to 9.001 year at pH 7 at 25 degree Celsius. This indicates that the test substance is considered to be persistent at environmentally relevant pHs (US EPA, 2020).

Key value for chemical safety assessment

Half-life for hydrolysis:

74.38 d

at the temperature of:

25 °C

Additional information

The hydrolysis rate constants and half-life values of the test substance was estimated using the HYDROWIN v2.0 program (EPI SuiteTM v4.11). Since the test substance is a UVCB with similar constituents varying mainly in carbon chain lengths, the half-life values were estimated for the individual components at pH 7 and pH 8. SMILES codes were used as the input parameter for the BCF value estimation for the individual constituents. The half-life values for the constituents of test substance were from 74.38 to 328.76 days at pH 7 and from 2.036 to 9.001 year at pH 7 at 25 degree Celsius. This indicates that the test substance is considered to be persistent at environmentally relevant pHs (US EPA, 2020).