Registration Dossier

Administrative data

Endpoint:
hydrolysis
Type of information:
calculation (if not (Q)SAR)
Remarks:
Migrated phrase: estimated by calculation
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Scientifically acceptable method

Data source

Referenceopen allclose all

Reference Type:
other: EPI Suite calculation (v4.11)
Title:
Unnamed
Year:
2018
Report date:
2018
Reference Type:
other: Estimation software
Title:
Estimation Programs Interface Suite for Microsoft Windows, v4.11
Author:
US EPA
Year:
2012
Bibliographic source:
United States Environmental Protection Agency, Washington, DC, USA

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Calculation of aqueous hydrolysis rate constant. Software used: SRC HYDROWIN v2.00
GLP compliance:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
1,4-butanediyl diacrylate
EC Number:
213-979-6
EC Name:
1,4-butanediyl diacrylate
Cas Number:
1070-70-8
Molecular formula:
C10H14O4
IUPAC Name:
1,4-butanediyl diacrylate

Study design

Estimation method (if used):
HYDROWIN v2.00 (chemical class: Ester)

Results and discussion

Transformation products:
no
Dissipation DT50 of parent compoundopen allclose all
pH:
8
Temp.:
25 °C
DT50:
1.191 yr
Type:
(pseudo-)first order (= half-life)
Remarks on result:
other: Kb half-life; The substance is (not) within the applicability domain of the model.
pH:
7
Temp.:
25 °C
DT50:
11.906 yr
Type:
(pseudo-)first order (= half-life)
Remarks on result:
other: Kb half-life; The substance is (not) within the applicability domain of the model.
Other kinetic parameters:
Kb hydrolysis at atom # 2: 9.224E-003 L/mol-sec
Kb hydrolysis at atom # 9: 9.224E-003 L/mol-sec

Total Kb for pH > 8 at 25 deg C : 1.845E-002 L/mol-sec

Applicant's summary and conclusion

Executive summary:

QPRF: HYDROWIN v2.00

 

1.

Substance

See “Test material identity”

2.

General information

 

2.1

Date of QPRF

16. Jan 2018

2.2

QPRF author and contact details

BASF SE, Dept. for Product Safety, Ludwigshafen, Germany

3.

Prediction

3.1

Endpoint
(OECD Principle 1)

Endpoint

Aqueous hydrolysis rate

Dependent variable

Hydrolytic half-life

3.2

Algorithm
(OECD Principle 2)

Model or submodel name

WSKOWWIN

Model version

v. 2.00

Reference to QMRF

Estimation of Aqueous Hydrolysis Rate Constants using HYDROWIN v2.00 (EPI Suite v4.11) (QMRF)

Predicted value (model result)

See “Results and discussion”

Input for prediction

Chemical structure via CAS number or SMILES

Descriptor values

- SMILES: structure of the compound as SMILES notation

Fragment values:

- Taft constant (sigma*)

- Steric factor (Es)

- Hammett constants (sigma-meta and sigma-para)

3.3

Applicability domain
(OECD principle 3)

Domains:

1) Chemical class

An equation for the estimation of the aqueous hydrolytic rate constant is available for the chemical class of the substance.

2) Fragments (On-Line HYDROWIN User’s Guide, Appendix E)

All fragments were identified.

3.4

The uncertainty of the prediction
(OECD principle 4)

According to REACH Guidance Document R.7a, (Nov. 2012), hydrolysis kinetics are usually determined experimentally. The guidance document also lists HYDROWIN as a means to estimate the hydrolytic half-life. The estimation is limited to only a few chemical classes. The model marks uncertainties of the estimate due to substitute values for missing fragments. As yet, the QSAR equations in HYDROWIN have not been rigorously tested with an external validation dataset. Currently, the number of chemicals with evaluated hydrolysis rates is relatively small in number, and the available data have been used to train the QSAR regressions. The training data set for esters has an acceptable size (n = 124). Equations for the other chemical classes were developed on very small databases (n = 7 to 20); therefore the reliability of estimations for members of other chemical classes than esters is low.

3.5

The chemical mechanisms according to the model underpinning the predicted result
(OECD principle 5)

Hydrolysis is a common degradation route in the environment, where reaction of a substance with water with a net exchange of the X group with an OH at the reaction centre such that RX + H2O →ROH + HX. Hydrolysis is often dependent upon pH as the reaction is commonly catalysed by hydrogen or hydroxide ions.

The model uses the principle of linear free energy relationships (LFER) to estimate the aqueous hydrolysis rate.

References

- US EPA (2012). On-Line HYDROWIN User’s Guide, Appendix E: Fragment Substituent Values Used by HYDROWIN.

- ECHA (2012). REACH Guidance Document R.7a, (Nov. 2012). 381 pp.

Identified fragments for the current substance: