Reaction products of tetrabromophthalic anhydride with 2,2'-oxydiethanol and methyloxirane

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Type of information:

calculation (if not (Q)SAR)

Remarks:

Migrated phrase: estimated by calculation

Adequacy of study:

key study

Study period:

February 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

1. SOFTWARE : Episuit Hydrowin

2. MODEL (incl. version number) 2.2

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL: CAS: 77098-07-8
Model used:
SMILES : O=C(c1c(c(c(c(c1C(=O)OCCOCCO)Br)Br)Br)Br)OCC(C)O
CHEM : 1,2-Benzenedicarboxylic acid, 3,4,5,6-tetrabromo-, mixed esters with
diethylene glycol and propylene glycol
MOL FOR: C15 H16 Br4 O7
MOL WT : 627.91

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
[Explain how the model fulfils the OECD principles for (Q)SAR model validation. Consider attaching the QMRF or providing a link]
- Defined endpoint: ester hydrolysis is well validated in Hyrowin
- Unambiguous algorithm: yes
- Defined domain of applicability:
The following accuracy statistics are available for the Training Set QSARs from Mill et al. (1987):
The ester equation regression has the following statistics:
  number = 124
  correlation coef (r) = 0.982
correlation coef (r2) = 0.965
- Appropriate measures of goodness-of-fit and robustness and predictivity:
The ester equation regression has the following statistics:
  number = 124
  correlation coef (r) = 0.982
correlation coef (r2) = 0.965
- Mechanistic interpretation:
the main functional groups of the substance subject to hydrolysis are the ester groups. This is correcly identified by the moidel.
5. APPLICABILITY DOMAIN
- Structural and mechanistic domains:
Currently there is no universally accepted definition of model domain.  However, users may wish to consider the possibility that aqueous hydrolysis estimates are less accurate for compounds that have a functional group(s) or other structural features not represented in the training set (see also Section 8.4. below).
Esters are designated by the formula:
R1 - C(=O) - O - R2
In the training set, the R2 substituent is an alkyl carbon or an aromatic carbon.  T
- Similarity with analogues in the training set: The substance falls within the applicability domain of the training set.

6. ADEQUACY OF THE RESULT
[Explain how the prediction fits the purpose of classification and labelling and/or risk assessment]: All main components contain similar ester groups and therefore this result is relevant for the assessment.

Data source

Reference

Reference Type:

other: software program

Title:

Estimation Programs Interface (EPI) Suite™ v3.20 for Microsoft® Windows

Author:

Anonymous

Year:

2010

Bibliographic source:

U.S. Environmental Protection Agency, Washington, DC, U.S.A. http://www.epa.gov/opptintr/exposure/pubs/episuite.htm

Report date:

2018

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

EPI Suite v4.11

GLP compliance:

no

Test material

Test material information

1

Reference substance name:

Reaction products of 3,4,5,6-tetrabromobenzene-1,2-dicarboxylate with 2,2'-oxy-diethanol and 2-epoxypropane

EC Number:

616-436-5

Cas Number:

77098-07-8

Molecular formula:

Ester product of C8 H2 Br4 O4 with C4 H10 O3 and C3 H8 O2 and condensation products, thereof.

IUPAC Name:

Reaction products of 3,4,5,6-tetrabromobenzene-1,2-dicarboxylate with 2,2'-oxy-diethanol and 2-epoxypropane

Test material form:

not specified

Details on test material:

Modelling performed with CAS for complete substance, but only mono-ring substance with one ethylene-glycol unit and one propyleneglycol unit modelled. The ester bond is however common to all consituents and is essentially the same. However, limited solubility of the higher molecular weight constituents can limit hyrolysis in practice.

Radiolabelling:

no

Study design

Analytical monitoring:

no

Estimation method (if used):

EPI Suite v4.1 HYDROWIN v2.2

Results and discussion

Transformation products:

yes

Identity of transformation products

No.:

#1

Reference

Reference substance name:

Unnamed

IUPAC name:

2,2'-oxydiethanol

Inventory number:

InventoryMultipleMappingImpl [inventoryEntryValue=EC 203-872-2]

CAS number:

111-46-6

Identity:

Diethylene glycol

Identity:

Diethylenglykol

Molecular formula:

C4H10O3

Molecular weight:

106.12

SMILES notation:

O(CCO)CCO

InChl:

1S/C4H10O3/c5-1-3-7-4-2-6/h5-6H,1-4H2

Details on hydrolysis and appearance of transformation product(s):

- Pathways for transformation: Hydrolyis of the este bond and formation of 1,2-Benzenedicarboxylic acid, 3,4,5,6-
tetrabromo-, diethyleneglycol and propyleneglycol is the most plausible hydrolysis pathway. Ester hydrolyis is typically fastest in alkaline media,
- Other:

Dissipation DT50 of parent compound

Dissipation DT50 of parent compound 1

Key result

pH:

8

Temp.:

25 °C

Hydrolysis rate constant:

ca. 5.89 s-1

DT50:

ca. 1.363 d

Type:

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

Dissipation DT50 of parent compound 2

Key result

pH:

7

Temp.:

25 °C

DT50:

ca. 13.69 d

Type:

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

Other kinetic parameters:

pH > 8 and 25 deg. C
Kb 1 for the first ester group : 4.32 Lmol-1s-1 (ethyelenglycol ester)
Kb 2 for the second ester group: 1.57 Lmol-1s-1 (propylene glycol ester)
Kb total: 5.89 Lmol-1s-1
Half lives relate to complete hydrolysis of both ester groups.

Any other information on results incl. tables

Pathways for transformation: Hydrolyis of the este bond and formation of 1,2-Benzenedicarboxylic acid, 3,4,5,6-

tetrabromo-, diethyleneglycol and propyleneglycol is the most plausible hydrolysis pathway. Ester hydrolyis is typically fastest in alkaline media,

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Based on QSAR results on ester hydrolysis of the one ring component, a hydrolysis is likely to occur on all ester groups contained in the various components in a similar manner, provided the solubility is sufficient. Hydrolysis constants for the ethyleneglycol ester bond were predicted to be 4.32 Lmol-1s-1 and for the propyleneglycol ester bond 1.57 Lmol-1s-1 at pH > 8 and 25 deg. C.
The hysrolysis constant for the complete hydrolysis was predicted to be 5.89 Lmol-1s-1 at pH> 8 and 25 deg. C.
The half-live for complete hydrolysis of both ester bonds were 1.363 d a.t pH > 8 and 13.69 d at pH 7, both at 25 deg. C

Executive summary:

Based on QSAR results on ester hydrolysis of the one ring component, a hydrolysis is likely to occur on all ester groups contained in the various components in a similar manner, provided the solubility is sufficient. Hydrolysis constants for the ethyleneglycol ester bond were predicted to be  4.32 Lmol-1s-1 and for the propyleneglycol ester bond 1.57 Lmol-1s-1 at   pH > 8 and 25 deg. C.

The hydrolysis constant for the complete hydrolysis was predicted to  be 5.89  Lmol-1s-1 at pH> 8 and 25 deg. C.

The half-live for complete hydrolysis of both ester bonds were 1.363 d a.t pH > 8 and 13.69 d at pH 7, both at 25 deg. C