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Hydrolysis

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Endpoint:
hydrolysis
Type of information:
(Q)SAR
Adequacy of study:
weight of evidence
Study period:
2013
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:
1. SOFTWARE: EPI Suite, EPA's Office of Pollution Prevention Toxics and Syracuse Research Corporation (SRC)

2. MODEL (incl. version number): HYDROWIN V2.00

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL: C(=O)(CCCCCCCC=CCC(CCCCCC)OS(=O)(=O)O[Na])OCC(COC(=O)CCCCCCCC=CCC(O)CCCCCC)OC(=O)CCCCCCCC=CCC(O)CCCCCC

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL: The moel is included in the EPI Suite software which the QSAR toolbox refers to. The model is presented in the On-line User's Guide with some limits, due to the fact that: the QSAR equations in the model have not been rigorously tested with an external validation dataset; that 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. Notwithstanding this, it is understood that the model can provide a weight-of-evidence for the hydrolysis endpoint in the case of sulfated oils.

5. APPLICABILITY DOMAIN: Currently there is no universally accepted definition of model domain. The model domain is based on a large number of fragments that includes esters, alkyl chains with double bonds and hydroxyl groups. However, the precise fatty acid chains of the representative molecules of sulfated oils are not included. Therefore, the model applies the correction factor for the use of "substitutes" for prediction purposes. The substitutes, chosen by the model, do not include doble bonds and hydroxyl groups that can be present in certain sulfated oils and the alkyl chains are shorter than the ones of fatty acids typically present in this kind of molecules. Notwithstanding this, it is considered that still the representative molecules of sulfated oils fall within the applicability domain; actually, the double bonds, hydroxyl groups and sulfate groups are not so close to the ester groups ("farther" than the end of the substitute chain), and their polarity should not affect so much the hydrolysis of the ester groups; further, the steric factor seems not to be influenced very much by the chain length of the substitute (please, see section below, "Any other information on material and methods incl. tables").

6. ADEQUACY OF THE RESULT: Considered the above, there is some uncertainty as to the accuracy of the hydrolysis prediction using this model; however, the results are used in a weight-of evidence approach to provide a magnitude order for the hydrolysis constants rates for sulfated oils. Likely, the prediction underestimates the half-life against hydrolysis,
Guideline:
other: ECHA Guidance on information requirements and chemical safety assessment - Chapter R.06: QSARs and grouping of chemicals - May2008
Principles of method if other than guideline:
The Aqueous Hydrolysis Rate Program (HYDROWIN) is a QSAR module in EPI Suite that estimates aqueous hydrolysis rate constants and half-lives of multiple classes of organic compounds, including esters, based on the method described by 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.  Menlo Park, CA: SRI International (1987).
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 acid- and base-catalyzed rate constants are used to calculate hydrolysis half-lives and selected pHs.
GLP compliance:
no
Specific details on test material used for the study:
SMILES notation: HN(H)(H)OS(=O)(=O)OC(CCC=CCC=CCC=CCC=CCC=CCCC(=O)OCC(COC(=O)CCCCCCCC=CCCCCCCCCCC)OC(=O)CCCC=CCC=CCC=CCC=CCC=CCC)CC
Transformation products:
no
Remarks:
See Details on hydrolysis and appearance of transformation product(s).
Details on hydrolysis and appearance of transformation product(s):
Given the complexity of the substance it is quite difficut to identify all the possible transformation products by means of reference substance(s).
In general, the hydrolysis of ester functional groups thsat link glycerol to fatty acids (partially sulfated) gives rise to free fatty acids, partially sulfated. and mono- and di-glycerides, partially sulfated.
pH:
7
Temp.:
25 °C
DT50:
ca. 1.2 yr
pH:
8
Temp.:
25 °C
DT50:
ca. 42 d
Other kinetic parameters:
Total Kb for pH > 8 at 25 deg C : 1.893E-001  L/mol-sec

SMILES : HN(H)(H)OS(=O)(=O)OC(CCC=CCC=CCC=CCC=CCC=CCCC(=O)OCC(COC(=O)CCCCCCCC=

        CCCCCCCCCCC)OC(=O)CCCC=CCC=CCC=CCC=CCC=CCC)CC

CHEM   : Oils, fish, sulfated, ammonium salts

MOL FOR: C65 H106 N1 O10 S1

MOL WT : 1093.63

--------------------------- 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: -CH2-CH2-CH=CH2    

                                    ** R2: -CH2-CH2-O-CH3      

Kb hydrolysis at atom # 29:  1.059E-001  L/mol-sec

ESTER:  R1-C(=O)-O-R2                ** R1: n-Octyl-            

                                    ** R2: -CH2-CH2-O-CH3      

Kb hydrolysis at atom # 36:  6.204E-002  L/mol-sec

ESTER:  R1-C(=O)-O-R2                ** R1: n-Octyl-            

                                    ** R2: iso-Propyl-        

Kb hydrolysis at atom # 58:  2.141E-002  L/mol-sec

Total Kb for pH > 8 at 25 deg C :  1.893E-001  L/mol-sec

Kb Half-Life at pH 8:      42.376 days  

Kb Half-Life at pH 7:       1.160  years

Validity criteria fulfilled:
yes
Conclusions:
In aqueous media the molecule is predicted to be hydrolysed with half-lives of approximately 1.2 year at pH 7 and 42 days at pH 8.
Executive summary:

The stability of a representative molecule of sulfated oils (castor oil, sulfated, sodium salt) against hydrolysis was calculated using the software HYDROWIN v2.00.

A base-catalysed second-order hydrolysis rate constant of 1.893E-001 L/(mol-sec) at 25 deg C was estimated using a structure estimation method.

This corresponds to half-lives of approximately 1.2 year at pH 7 and 42 days at pH 8.

Endpoint:
hydrolysis
Type of information:
(Q)SAR
Adequacy of study:
weight of evidence
Study period:
2013
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:
1. SOFTWARE: EPI Suite, EPA's Office of Pollution Prevention Toxics and Syracuse Research Corporation (SRC)

2. MODEL (incl. version number): HYDROWIN V2.00

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL: C(=O)(CCCCCCCC=CCC(CCCCCC)OS(=O)(=O)O[Na])OCC(COC(=O)CCCCCCCC=CCC(O)CCCCCC)OC(=O)CCCCCCCC=CCC(O)CCCCCC

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL: The moel is included in the EPI Suite software which the QSAR toolbox refers to. The model is presented in the On-line User's Guide with some limits, due to the fact that: the QSAR equations in the model have not been rigorously tested with an external validation dataset; that 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. Notwithstanding this, it is understood that the model can provide a weight-of-evidence for the hydrolysis endpoint in the case of sulfated oils.

5. APPLICABILITY DOMAIN: Currently there is no universally accepted definition of model domain. The model domain is based on a large number of fragments that includes esters, alkyl chains with double bonds and hydroxyl groups. However, the precise fatty acid chains of the representative molecules of sulfated oils are not included. Therefore, the model applies the correction factor for the use of "substitutes" for prediction purposes. The substitutes, chosen by the model, do not include doble bonds and hydroxyl groups that can be present in certain sulfated oils and the alkyl chains are shorter than the ones of fatty acids typically present in this kind of molecules. Notwithstanding this, it is considered that still the representative molecules of sulfated oils fall within the applicability domain; actually, the double bonds, hydroxyl groups and sulfate groups are not so close to the ester groups ("farther" than the end of the substitute chain), and their polarity should not affect so much the hydrolysis of the ester groups; further, the steric factor seems not to be influenced very much by the chain length of the substitute (please, see section below, "Any other information on material and methods incl. tables").

6. ADEQUACY OF THE RESULT: Considered the above, there is some uncertainty as to the accuracy of the hydrolysis prediction using this model; however, the results are used in a weight-of evidence approach to provide a magnitude order for the hydrolysis constants rates for sulfated oils. Likely, the prediction underestimates the half-life against hydrolysis,
Guideline:
other: ECHA Guidance on information requirements and chemical safety assessment - Chapter R.06: QSARs and grouping of chemicals - May2008
Principles of method if other than guideline:
The Aqueous Hydrolysis Rate Program (HYDROWIN) is a QSAR module in EPI Suite that estimates aqueous hydrolysis rate constants and half-lives of multiple classes of organic compounds, including esters, based on the method described by 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.  Menlo Park, CA: SRI International (1987).
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 acid- and base-catalyzed rate constants are used to calculate hydrolysis half-lives and selected pHs.
GLP compliance:
no
Specific details on test material used for the study:
SMILES notation: C(=O)(CCC=CCC=CCC=CCC=CCC=CCCC(CC)OS(=O)(=O)O[Na])OCC(COC(=O)CCCCCCCC=CCCCCCCCCCC)OC(=O)CCCC=CCC=CCC=CCC=CCC=CCC
Transformation products:
no
Remarks:
See Details on hydrolysis and appearance of transformation product(s).
Details on hydrolysis and appearance of transformation product(s):
Given the complexity of the substance it is quite difficut to identify all the possible transformation products by means of reference substance(s).
In general, the hydrolysis of ester functional groups thsat link glycerol to fatty acids (partially sulfated) gives rise to free fatty acids, partially sulfated. and mono- and di-glycerides, partially sulfated.
pH:
7
Temp.:
25 °C
DT50:
ca. 1.2 yr
pH:
8
Temp.:
25 °C
DT50:
ca. 42 d
Other kinetic parameters:
Total Kb for pH > 8 at 25 deg C : 1.893E-001  L/mol-sec

SMILES : O=C(CCC=CCC=CCC=CCC=CCC=CCCC(CC)OS(=O)(=O)O[Na])OCC(COC(=O)CCCCCCCC=C

        CCCCCCCCCC)OC(=O)CCCC=CCC=CCC=CCC=CCC=CCC

CHEM   : Oils, fish, sulfated, sodium salts

MOL FOR: C65 H103 O10 S1 Na1

MOL WT : 1099.59

--------------------------- 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: -CH2-CH2-CH=CH2    

                                    ** R2: -CH2-CH2-O-CH3      

Kb hydrolysis at atom #  2:  1.059E-001  L/mol-sec

ESTER:  R1-C(=O)-O-R2                ** R1: n-Octyl-            

                                    ** R2: -CH2-CH2-O-CH3      

Kb hydrolysis at atom # 35:  6.204E-002  L/mol-sec

ESTER:  R1-C(=O)-O-R2                ** R1: n-Octyl-            

                                    ** R2: iso-Propyl-        

Kb hydrolysis at atom # 57:  2.141E-002  L/mol-sec

Total Kb for pH > 8 at 25 deg C :  1.893E-001  L/mol-sec

Kb Half-Life at pH 8:      42.376 days  

Kb Half-Life at pH 7:       1.160  years

Validity criteria fulfilled:
yes
Conclusions:
In aqueous media the molecule is predicted to be hydrolysed with half-lives of approximately 1.2 year at pH 7 and 42 days at pH 8.
Executive summary:

The stability of a representative molecule of sulfated oils (castor oil, sulfated, sodium salt) against hydrolysis was calculated using the software HYDROWIN v2.00.

A base-catalysed second-order hydrolysis rate constant of 1.893E-001 L/(mol-sec) at 25 deg C was estimated using a structure estimation method.

This corresponds to half-lives of approximately 1.2 year at pH 7 and 42 days at pH 8.

Endpoint:
hydrolysis
Type of information:
(Q)SAR
Adequacy of study:
weight of evidence
Study period:
2013
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:
1. SOFTWARE: EPI Suite, EPA's Office of Pollution Prevention Toxics and Syracuse Research Corporation (SRC)

2. MODEL (incl. version number): HYDROWIN V2.00

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL: C(=O)(CCCCCCCC=CCC(CCCCCC)OS(=O)(=O)O[Na])OCC(COC(=O)CCCCCCCC=CCC(O)CCCCCC)OC(=O)CCCCCCCC=CCC(O)CCCCCC

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL: The moel is included in the EPI Suite software which the QSAR toolbox refers to. The model is presented in the On-line User's Guide with some limits, due to the fact that: the QSAR equations in the model have not been rigorously tested with an external validation dataset; that 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. Notwithstanding this, it is understood that the model can provide a weight-of-evidence for the hydrolysis endpoint in the case of sulfated oils.

5. APPLICABILITY DOMAIN: Currently there is no universally accepted definition of model domain. The model domain is based on a large number of fragments that includes esters, alkyl chains with double bonds and hydroxyl groups. However, the precise fatty acid chains of the representative molecules of sulfated oils are not included. Therefore, the model applies the correction factor for the use of "substitutes" for prediction purposes. The substitutes, chosen by the model, do not include doble bonds and hydroxyl groups that can be present in certain sulfated oils and the alkyl chains are shorter than the ones of fatty acids typically present in this kind of molecules. Notwithstanding this, it is considered that still the representative molecules of sulfated oils fall within the applicability domain; actually, the double bonds, hydroxyl groups and sulfate groups are not so close to the ester groups ("farther" than the end of the substitute chain), and their polarity should not affect so much the hydrolysis of the ester groups; further, the steric factor seems not to be influenced very much by the chain length of the substitute (please, see section below, "Any other information on material and methods incl. tables").

6. ADEQUACY OF THE RESULT: Considered the above, there is some uncertainty as to the accuracy of the hydrolysis prediction using this model; however, the results are used in a weight-of evidence approach to provide a magnitude order for the hydrolysis constants rates for sulfated oils. Likely, the prediction underestimates the half-life against hydrolysis,
Guideline:
other: ECHA Guidance on information requirements and chemical safety assessment - Chapter R.06: QSARs and grouping of chemicals - May2008
Principles of method if other than guideline:
The Aqueous Hydrolysis Rate Program (HYDROWIN) is a QSAR module in EPI Suite that estimates aqueous hydrolysis rate constants and half-lives of multiple classes of organic compounds, including esters, based on the method described by 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.  Menlo Park, CA: SRI International (1987).
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 acid- and base-catalyzed rate constants are used to calculate hydrolysis half-lives and selected pHs.
GLP compliance:
no
Specific details on test material used for the study:
SMILES notation: HN(H)(H)OS(=O)(=O)OC(CCCCCCCC(=O)OCC(COC(=O)CCCCCCCC=CCCCCCCCC)OC(=O)CCCCCCCC=CCCCCCCCC)CCCCCCCCC
Transformation products:
no
Remarks:
See Details on hydrolysis and appearance of transformation product(s).
Details on hydrolysis and appearance of transformation product(s):
Given the complexity of the substance it is quite difficut to identify all the possible transformation products by means of reference substance(s).
In general, the hydrolysis of ester functional groups thsat link glycerol to fatty acids (partially sulfated) gives rise to free fatty acids, partially sulfated. and mono- and di-glycerides, partially sulfated.
pH:
7
Temp.:
25 °C
DT50:
ca. 1 yr
pH:
8
Temp.:
25 °C
DT50:
ca. 36.5 d
Other kinetic parameters:
Total Kb for pH > 8 at 25 deg C : 2.199E-001 L/mol-sec

SMILES : HN(H)(H)OS(=O)(=O)OC(CCCCCCCC(=O)OCC(COC(=O)CCCCCCCC=CCCCCCCCC)OC(=O)

        CCCCCCCC=CCCCCCCCC)CCCCCCCCC

CHEM   : Oils, vegetable, sulfated, ammonium salts

MOL FOR: C57 H108 N1 O10 S1

MOL WT : 999.56

--------------------------- 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-Heptyl-          

                                    ** R2: -CH2-CH2-O-CH3      

Kb hydrolysis at atom # 18:  1.365E-001  L/mol-sec

ESTER:  R1-C(=O)-O-R2                ** R1: n-Octyl-            

                                    ** R2: -CH2-CH2-O-CH3      

Kb hydrolysis at atom # 25:  6.204E-002  L/mol-sec

ESTER:  R1-C(=O)-O-R2                ** R1: n-Octyl-            

                                    ** R2: iso-Propyl-        

Kb hydrolysis at atom # 45:  2.141E-002  L/mol-sec

Total Kb for pH > 8 at 25 deg C :  2.199E-001  L/mol-sec

Kb Half-Life at pH 8:      36.473 days  

Kb Half-Life at pH 7:       0.999  years  

Validity criteria fulfilled:
yes
Conclusions:
In aqueous media the molecule is predicted to be hydrolysed with half-lives of approximately 1 year at pH 7 and 36 days at pH 8.
Executive summary:

The stability of a representative molecule of sulfated oils (castor oil, sulfated, sodium salt) against hydrolysis was calculated using the software HYDROWIN v2.00.

A base-catalysed second-order hydrolysis rate constant of 2.199E-001 L/(mol-sec) at 25 deg C was estimated using a structure estimation method.

This corresponds to half-lives of approximately 1 year at pH 7 and 36 days at pH 8.

Endpoint:
hydrolysis
Type of information:
(Q)SAR
Adequacy of study:
weight of evidence
Study period:
2013
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:
1. SOFTWARE: EPI Suite, EPA's Office of Pollution Prevention Toxics and Syracuse Research Corporation (SRC)

2. MODEL (incl. version number): HYDROWIN V2.00

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL: C(=O)(CCCCCCCC=CCC(CCCCCC)OS(=O)(=O)O[Na])OCC(COC(=O)CCCCCCCC=CCC(O)CCCCCC)OC(=O)CCCCCCCC=CCC(O)CCCCCC

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL: The moel is included in the EPI Suite software which the QSAR toolbox refers to. The model is presented in the On-line User's Guide with some limits, due to the fact that: the QSAR equations in the model have not been rigorously tested with an external validation dataset; that 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. Notwithstanding this, it is understood that the model can provide a weight-of-evidence for the hydrolysis endpoint in the case of sulfated oils.

5. APPLICABILITY DOMAIN: Currently there is no universally accepted definition of model domain. The model domain is based on a large number of fragments that includes esters, alkyl chains with double bonds and hydroxyl groups. However, the precise fatty acid chains of the representative molecules of sulfated oils are not included. Therefore, the model applies the correction factor for the use of "substitutes" for prediction purposes. The substitutes, chosen by the model, do not include doble bonds and hydroxyl groups that can be present in certain sulfated oils and the alkyl chains are shorter than the ones of fatty acids typically present in this kind of molecules. Notwithstanding this, it is considered that still the representative molecules of sulfated oils fall within the applicability domain; actually, the double bonds, hydroxyl groups and sulfate groups are not so close to the ester groups ("farther" than the end of the substitute chain), and their polarity should not affect so much the hydrolysis of the ester groups; further, the steric factor seems not to be influenced very much by the chain length of the substitute (please, see section below, "Any other information on material and methods incl. tables").

6. ADEQUACY OF THE RESULT: Considered the above, there is some uncertainty as to the accuracy of the hydrolysis prediction using this model; however, the results are used in a weight-of evidence approach to provide a magnitude order for the hydrolysis constants rates for sulfated oils. Likely, the prediction underestimates the half-life against hydrolysis,
Guideline:
other: ECHA Guidance on information requirements and chemical safety assessment - Chapter R.06: QSARs and grouping of chemicals - May2008
Principles of method if other than guideline:
The Aqueous Hydrolysis Rate Program (HYDROWIN) is a QSAR module in EPI Suite that estimates aqueous hydrolysis rate constants and half-lives of multiple classes of organic compounds, including esters, based on the method described by 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.  Menlo Park, CA: SRI International (1987).
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 acid- and base-catalyzed rate constants are used to calculate hydrolysis half-lives and selected pHs.
GLP compliance:
no
Specific details on test material used for the study:
SMILES notation: C(=O)(CCCCCCCC=CCCCCCCCC)OC(COC(=O)CCCCCCCC=CCCCCCCCC)COC(=O)CCCCCCCC(CCCCCCCCC)OS(=O)(=O)O[Na]
Transformation products:
no
Remarks:
See Details on hydrolysis and appearance of transformation product(s).
Details on hydrolysis and appearance of transformation product(s):
Given the complexity of the substance it is quite difficut to identify all the possible transformation products by means of reference substance(s).
In general, the hydrolysis of ester functional groups thsat link glycerol to fatty acids (partially sulfated) gives rise to free fatty acids, partially sulfated. and mono- and di-glycerides, partially sulfated.
pH:
7
Temp.:
25 °C
DT50:
ca. 1 yr
pH:
8
Temp.:
25 °C
DT50:
ca. 36.5 d
Other kinetic parameters:
Total Kb for pH > 8 at 25 deg C : 2.199E-001 L/mol-sec

SMILES : HN(H)(H)OS(=O)(=O)OC(CCCCCCCC(=O)OCC(COC(=O)CCCCCCCC=CCCCCCCCC)OC(=O)

        CCCCCCCC=CCCCCCCCC)CCCCCCCCC

CHEM   : Oils, vegetable, sulfated, ammonium salts

MOL FOR: C57 H108 N1 O10 S1

MOL WT : 999.56

--------------------------- 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-Heptyl-          

                                    ** R2: -CH2-CH2-O-CH3      

Kb hydrolysis at atom # 18:  1.365E-001  L/mol-sec

ESTER:  R1-C(=O)-O-R2                ** R1: n-Octyl-            

                                    ** R2: -CH2-CH2-O-CH3      

Kb hydrolysis at atom # 25:  6.204E-002  L/mol-sec

ESTER:  R1-C(=O)-O-R2                ** R1: n-Octyl-            

                                    ** R2: iso-Propyl-        

Kb hydrolysis at atom # 45:  2.141E-002  L/mol-sec

Total Kb for pH > 8 at 25 deg C :  2.199E-001  L/mol-sec

Kb Half-Life at pH 8:      36.473 days  

Kb Half-Life at pH 7:       0.999  years  

Validity criteria fulfilled:
yes
Conclusions:
In aqueous media the molecule is predicted to be hydrolysed with half-lives of approximately 1 year at pH 7 and 36 days at pH 8.
Executive summary:

The stability of a representative molecule of sulfated oils (castor oil, sulfated, sodium salt) against hydrolysis was calculated using the software HYDROWIN v2.00.

A base-catalysed second-order hydrolysis rate constant of 2.199E-001 L/(mol-sec) at 25 deg C was estimated using a structure estimation method.

This corresponds to half-lives of approximately 1 year at pH 7 and 36 days at pH 8.

Endpoint:
hydrolysis
Type of information:
(Q)SAR
Adequacy of study:
weight of evidence
Study period:
2013
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:
1. SOFTWARE: EPI Suite, EPA's Office of Pollution Prevention Toxics and Syracuse Research Corporation (SRC)

2. MODEL (incl. version number): HYDROWIN V2.00

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL: C(=O)(CCCCCCCC=CCC(CCCCCC)OS(=O)(=O)O[Na])OCC(COC(=O)CCCCCCCC=CCC(O)CCCCCC)OC(=O)CCCCCCCC=CCC(O)CCCCCC

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL: The moel is included in the EPI Suite software which the QSAR toolbox refers to. The model is presented in the On-line User's Guide with some limits, due to the fact that: the QSAR equations in the model have not been rigorously tested with an external validation dataset; that 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. Notwithstanding this, it is understood that the model can provide a weight-of-evidence for the hydrolysis endpoint in the case of sulfated oils.

5. APPLICABILITY DOMAIN: Currently there is no universally accepted definition of model domain. The model domain is based on a large number of fragments that includes esters, alkyl chains with double bonds and hydroxyl groups. However, the precise fatty acid chains of the representative molecules of sulfated oils are not included. Therefore, the model applies the correction factor for the use of "substitutes" for prediction purposes. The substitutes, chosen by the model, do not include doble bonds and hydroxyl groups that can be present in certain sulfated oils and the alkyl chains are shorter than the ones of fatty acids typically present in this kind of molecules. Notwithstanding this, it is considered that still the representative molecules of sulfated oils fall within the applicability domain; actually, the double bonds, hydroxyl groups and sulfate groups are not so close to the ester groups ("farther" than the end of the substitute chain), and their polarity should not affect so much the hydrolysis of the ester groups; further, the steric factor seems not to be influenced very much by the chain length of the substitute (please, see section below, "Any other information on material and methods incl. tables").

6. ADEQUACY OF THE RESULT: Considered the above, there is some uncertainty as to the accuracy of the hydrolysis prediction using this model; however, the results are used in a weight-of evidence approach to provide a magnitude order for the hydrolysis constants rates for sulfated oils. Likely, the prediction underestimates the half-life against hydrolysis,
Guideline:
other: ECHA Guidance on information requirements and chemical safety assessment - Chapter R.06: QSARs and grouping of chemicals - May2008
Principles of method if other than guideline:
The Aqueous Hydrolysis Rate Program (HYDROWIN) is a QSAR module in EPI Suite that estimates aqueous hydrolysis rate constants and half-lives of multiple classes of organic compounds, including esters, based on the method described by 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.  Menlo Park, CA: SRI International (1987).
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 acid- and base-catalyzed rate constants are used to calculate hydrolysis half-lives and selected pHs.
GLP compliance:
no
Specific details on test material used for the study:
SMILES notation: HN(H)(H)OS(=O)(=O)OC(CC=CCCCCCCCC(=O)OCC(COC(=O)CCCCCCCC=CCC(O)CCCCCC)OC(=O)CCCCCCCC=CCC(O)CCCCCC)CCCCCC
Transformation products:
no
Remarks:
See Details on hydrolysis and appearance of transformation product(s)
Details on hydrolysis and appearance of transformation product(s):
Given the complexity of the substance it is quite difficut to identify all the possible transformation products by means of reference substance(s).
In general, the hydrolysis of ester functional groups thsat link glycerol to fatty acids (partially sulfated) gives rise to free fatty acids, partially sulfated. and mono- and di-glycerides, partially sulfated.
pH:
7
Temp.:
25 °C
DT50:
ca. 1.5 yr
pH:
8
Temp.:
25 °C
DT50:
ca. 55 d
Other kinetic parameters:
Total Kb for pH > 8 at 25 deg C : 1.455E-001 L/mol-sec

SMILES : HN(H)(H)OS(=O)(=O)OC(CC=CCCCCCCCC(=O)OCC(COC(=O)CCCCCCCC=CCC(O)CCCCCC

        )OC(=O)CCCCCCCC=CCC(O)CCCCCC)CCCCCC

CHEM   : Castor oil, sulfated, ammonium salt

MOL FOR: C57 H106 N1 O12 S1

MOL WT : 1029.54

--------------------------- 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-CH2-O-CH3      

Kb hydrolysis at atom # 21:  6.204E-002  L/mol-sec

ESTER:  R1-C(=O)-O-R2                ** R1: n-Octyl-            

                                    ** R2: -CH2-CH2-O-CH3      

Kb hydrolysis at atom # 28:  6.204E-002  L/mol-sec

ESTER:  R1-C(=O)-O-R2                ** R1: n-Octyl-            

                                    ** R2: iso-Propyl-        

Kb hydrolysis at atom # 49:  2.141E-002  L/mol-sec

Total Kb for pH > 8 at 25 deg C :  1.455E-001  L/mol-sec

Kb Half-Life at pH 8:      55.135 days  

Kb Half-Life at pH 7:       1.510  years  

Validity criteria fulfilled:
yes
Conclusions:
In aqueous media the molecule is predicted to be hydrolysed with half-lives of approximately 1.5 years at pH 7 and 55 days at pH 8.
Executive summary:

The stability of a representative molecule of sulfated oils (castor oil, sulfated, sodium salt) against hydrolysis was calculated using the software HYDROWIN v2.00.

A base-catalysed second-order hydrolysis rate constant of 1.455E-001 L/(mol-sec) at 25 deg C was estimated using a structure estimation method.

This corresponds to half-lives of approximately 1.5 years at pH 7 and 55 days at pH 8.

Endpoint:
hydrolysis
Type of information:
(Q)SAR
Adequacy of study:
weight of evidence
Study period:
2013
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:
1. SOFTWARE: EPI Suite, EPA's Office of Pollution Prevention Toxics and Syracuse Research Corporation (SRC)

2. MODEL (incl. version number): HYDROWIN V2.00

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL: C(=O)(CCCCCCCC=CCC(CCCCCC)OS(=O)(=O)O[Na])OCC(COC(=O)CCCCCCCC=CCC(O)CCCCCC)OC(=O)CCCCCCCC=CCC(O)CCCCCC

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL: The moel is included in the EPI Suite software which the QSAR toolbox refers to. The model is presented in the On-line User's Guide with some limits, due to the fact that: the QSAR equations in the model have not been rigorously tested with an external validation dataset; that 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. Notwithstanding this, it is understood that the model can provide a weight-of-evidence for the hydrolysis endpoint in the case of sulfated oils.

5. APPLICABILITY DOMAIN: Currently there is no universally accepted definition of model domain. The model domain is based on a large number of fragments that includes esters, alkyl chains with double bonds and hydroxyl groups. However, the precise fatty acid chains of the representative molecules of sulfated oils are not included. Therefore, the model applies the correction factor for the use of "substitutes" for prediction purposes. The substitutes, chosen by the model, do not include doble bonds and hydroxyl groups that can be present in certain sulfated oils and the alkyl chains are shorter than the ones of fatty acids typically present in this kind of molecules. Notwithstanding this, it is considered that still the representative molecules of sulfated oils fall within the applicability domain; actually, the double bonds, hydroxyl groups and sulfate groups are not so close to the ester groups ("farther" than the end of the substitute chain), and their polarity should not affect so much the hydrolysis of the ester groups; further, the steric factor seems not to be influenced very much by the chain length of the substitute (please, see section below, "Any other information on material and methods incl. tables").

6. ADEQUACY OF THE RESULT: Considered the above, there is some uncertainty as to the accuracy of the hydrolysis prediction using this model; however, the results are used in a weight-of evidence approach to provide a magnitude order for the hydrolysis constants rates for sulfated oils. Likely, the prediction underestimates the half-life against hydrolysis,
Guideline:
other: ECHA Guidance on information requirements and chemical safety assessment - Chapter R.06: QSARs and grouping of chemicals - May2008
Principles of method if other than guideline:
The Aqueous Hydrolysis Rate Program (HYDROWIN) is a QSAR module in EPI Suite that estimates aqueous hydrolysis rate constants and half-lives of multiple classes of organic compounds, including esters, based on the method described by 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.  Menlo Park, CA: SRI International (1987).
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 acid- and base-catalyzed rate constants are used to calculate hydrolysis half-lives and selected pHs.
GLP compliance:
no
Specific details on test material used for the study:
SMILES notation: C(=O)(CCCCCCCC=CCC(CCCCCC)OS(=O)(=O)O[Na])OCC(COC(=O)CCCCCCCC=CCC(O)CCCCCC)OC(=O)CCCCCCCC=CCC(O)CCCCCC
Transformation products:
no
Remarks:
See Details on hydrolysis and appearance of transformation product(s)
Details on hydrolysis and appearance of transformation product(s):
Given the complexity of the substance it is quite difficut to identify all the possible transformation products by means of reference substance(s).
In general, the hydrolysis of ester functional groups thsat link glycerol to fatty acids (partially sulfated) gives rise to free fatty acids, partially sulfated. and mono- and di-glycerides, partially sulfated.
pH:
7
Temp.:
25 °C
DT50:
ca. 1.5 yr
pH:
8
Temp.:
25 °C
DT50:
ca. 55 d
Other kinetic parameters:
Total Kb for pH > 8 at 25 deg C : 1.455E-001 L/mol-sec

SMILES : O=C(CCCCCCCC=CCC(CCCCCC)OS(=O)(=O)O[Na])OCC(COC(=O)CCCCCCCC=CCC(O)CCC

        CCC)OC(=O)CCCCCCCC=CCC(O)CCCCCC

CHEM   : Castor oil, sulfated, sodium salt

MOL FOR: C57 H103 O12 S1 Na1

MOL WT : 1035.50

--------------------------- 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: n-Octyl-            

                                    ** R2: -CH2-CH2-O-CH3      

Kb hydrolysis at atom #  2:  6.204E-002  L/mol-sec

ESTER:  R1-C(=O)-O-R2               ** R1: n-Octyl-            

                                    ** R2: -CH2-CH2-O-CH3      

Kb hydrolysis at atom # 31:  6.204E-002  L/mol-sec

ESTER:  R1-C(=O)-O-R2               ** R1: n-Octyl-            

                                    ** R2: iso-Propyl-        

Kb hydrolysis at atom # 52:  2.141E-002  L/mol-sec

Total Kb for pH > 8 at 25 deg C :  1.455E-001  L/mol-sec

Kb Half-Life at pH 8:      55.135 days  

Kb Half-Life at pH 7:       1.510  years  

Validity criteria fulfilled:
yes
Conclusions:
In aqueous media the molecule is predicted to be hydrolysed with half-lives of approximately 1.5 years at pH 7 and 55 days at pH 8.
Executive summary:

The stability of a representative molecule of sulfated oils (castor oil, sulfated, sodium salt) against hydrolysis was calculated using the software HYDROWIN v2.00.

A base-catalysed second-order hydrolysis rate constant of 1.455E-001 L/(mol-sec) at 25 deg C was estimated using a structure estimation method.

This corresponds to half-lives of approximately 1.5 years at pH 7 and 55 days at pH 8.

Description of key information

Half-lives of 42 days at pH8 and 1.2 years at pH 7 are predicted.

Key value for chemical safety assessment

Half-life for hydrolysis:
1.2 yr
at the temperature of:
25 °C

Additional information

The rate of hydrolysis of the representative molecules of sulfated oils in aqueous media has been estimated using HYDROWIN V2.00 from EPI Suite.

Half-lives of 1 to 1.5 years (average 1.2 years) at pH7 and 36 to 55 days (average 44 days) at pH 8 are predicted.