Fatty acids C16-18 (even numbered), mono, di and tri esters with sucrose

Hydrolysis

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

hydrolysis

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

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

Qualifier:

according to guideline

Guideline:

other:

Version / remarks:

REACH Guidance on QSARs R.6

Principles of method if other than guideline:

- Software tool(s) used including version: EPI Suite v4.11
- Model(s) used: HYDROWIN v2.00
Full reference and details of the used formulas can be found in:
Mill, T., Haag, W., Penwell, P., Pettit, T. and Johnson, H. "Environmental Fate and Exposure Studies Development of a PC-SAR for Hydrolysis: Esters, Alkyl Halides and Epoxides". EPA Contract No. 68-02-4254: SRI International (1987).
- Model description: see field 'Justification for non-standard information', 'Attached justification' and 'any other information on material and methods'
- Justification of QSAR prediction: see field 'Justification for type of information', 'Attached justification' and/or 'overall remarks'

GLP compliance:

no

Estimation method (if used):

- Total Kb for pH > 8: 8.345E-002 L/mol sec
- Temperature for which rate constant was calculated: 25 °C
- Computer programme: HYDROWIN v2.00

Transformation products:

not specified

pH:

7

Temp.:

25 °C

DT50:

2.632 yr

pH:

8

Temp.:

25 °C

DT50:

96.126 d

For detailed information on the results please refer to the attached report. The results refer to the uncharged molecule.

Reference 2

Endpoint:

hydrolysis

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

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

Qualifier:

according to guideline

Guideline:

other:

Version / remarks:

REACH Guidance on QSARs R.6

Principles of method if other than guideline:

- Software tool(s) used including version: EPI Suite v4.11
- Model(s) used: HYDROWIN v2.00
Full reference and details of the used formulas can be found in:
Mill, T., Haag, W., Penwell, P., Pettit, T. and Johnson, H. "Environmental Fate and Exposure Studies Development of a PC-SAR for Hydrolysis: Esters, Alkyl Halides and Epoxides". EPA Contract No. 68-02-4254: SRI International (1987).
- Model description: see field 'Justification for non-standard information', 'Attached justification' and 'any other information on material and methods'
- Justification of QSAR prediction: see field 'Justification for type of information', 'Attached justification' and/or 'overall remarks'

GLP compliance:

no

Estimation method (if used):

- Total Kb for pH > 8: 2.141E-002 L/mol sec
- Temperature for which rate constant was calculated: 25 °C
- Computer programme: HYDROWIN v2.00

Transformation products:

not specified

pH:

7

Temp.:

25 °C

DT50:

1.026 yr

pH:

8

Temp.:

25 °C

DT50:

10.259 yr

For detailed information on the results please refer to the attached report. The results refer to the uncharged molecule.

Reference 3

Endpoint:

hydrolysis

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

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

Qualifier:

according to guideline

Guideline:

other:

Version / remarks:

REACH Guidance on QSARs R.6

Principles of method if other than guideline:

- Software tool(s) used including version: EPI Suite v4.11
- Model(s) used: HYDROWIN v2.00
Full reference and details of the used formulas can be found in:
Mill, T., Haag, W., Penwell, P., Pettit, T. and Johnson, H. "Environmental Fate and Exposure Studies Development of a PC-SAR for Hydrolysis: Esters, Alkyl Halides and Epoxides". EPA Contract No. 68-02-4254: SRI International (1987).
- Model description: see field 'Justification for non-standard information', 'Attached justification' and 'any other information on material and methods'
- Justification of QSAR prediction: see field 'Justification for type of information', 'Attached justification' and/or 'overall remarks'

GLP compliance:

no

Estimation method (if used):

- Total Kb for pH > 8: 6.204E-002 L/mol sec, 2.141E-002 L/mol sec
- Temperature for which rate constant was calculated: 25 °C
- Computer programme: HYDROWIN v2.00

Transformation products:

not specified

pH:

7

Temp.:

25 °C

DT50:

55.135 d

pH:

8

Temp.:

25 °C

DT50:

1.51 yr

For detailed information on the results please refer to the attached report. The results refer to the uncharged molecule.

Description of key information

Hydrolysis of the substance is not expected under environmental conditions.

Additional information

No experimental studies investigating the hydrolysis of the test item in water are available. QSAR calculations using HYDROWIN v2.00 indicated that the substance does not hydrolyze quickly in the environment. The calculations revealed a DT50 at pH7 (25 °C) of 55.14 days to > 1 year. Even though some fragments of the target substance are not available within the model (and substitutes were used instead) this result is in line with experimental determination of hydrolytic degradation under acidic acetic (pH 2, 3 and 4) conditions (Okumura et al., 2011). Okumura et al. investigated the hydrolytic behavior of sucrose monolaurate and sucrose monostearate. Since sucrose monostearate is one of the constituents of the target substance, this result can adequately be used for the assessment. The hydrolytic degradation was investigated in diluted hydrochloric acid at pH 2, 3 and 4 at 70 °C. At pH 2 significant hydrolysis of sucrose monostearate was recorded wheareas the hydrolytic degradation decreased significantly at pH 3. At pH 4 almost no hydrolytic degradation could be measured. A re-calculation from 70 °C to 25 °C indicated a lifetime of sucrose monostearate of approx. 12 years. Since the hydrolytic degradation significantly changed from the conditions at pH 2 to pH 4 it was assumed that sucrose monostearate is hydrolytically stable under neutral conditions. Even though the hydrolytic stability of higher esterified esters was not tested it was concluded by the authors of the study that hydrolysis is assumed to be much slower with higher esterification. Since the glycosidic bond is sterically more protected by the increased number of bulky di- and triesters the substance is assumed to have an even higher stability to hydrolytic degradation.
In conclusion, sucrose mono-, di- and triesters are assumed to be hydrolytically stable under environmental conditions.