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Hydrolysis

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Endpoint:
hydrolysis
Data waiving:
study technically not feasible
Justification for data waiving:
the study does not need to be conducted because the substance is highly insoluble in water
Justification for type of information:
JUSTIFICATION FOR DATA WAIVING (see supporting expert statement)
The feasibility of a hydrolysis study with the test item was assessed based on the performed tests, i.e. water solubility and analytics. As a consequence of the very low water solubility of the test item a solubility test was performed using different solvents to determine the appropriate solvent for the preparation of the stock solution and the sample solution. In a second step, the analytical behaviour of the test item was investigated in order to obtain an analytical method for the analysis of the sample solution with an appropriate sensitivity considering the potential amount of the test item in the aqueous test solution.
The results of the experiments indicated that reproducible analytical results could only be obtained in absence of water. This could be traced back either to the very low solubility or to the stability of the test item in water.
A study to investigate the hydrolytic properties of the test item cannot be performed. Regarding the estimated water solubility of  1.171*10exp(-8) mg/L (at 25°C) no analytical method with the appropriate sensitivity is available or could be developed. Moreover, it can be assumed that only a negligible portion of the test item will enter the aquatic environment as soluble substance and hence the impact on the aquatic environment was considered to be of low extent.
Hence, it can be concluded that hydrolysis testing is neither technically feasible nor required.
Reason / purpose for cross-reference:
data waiving: supporting information
Reason / purpose for cross-reference:
data waiving: supporting information
Endpoint:
hydrolysis
Type of information:
other: Expert Statement supported by experimental results
Adequacy of study:
supporting study
Study period:
until 2016-11-14
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Expert statement supported well-documented experimental results
Reason / purpose for cross-reference:
data waiving: supporting information
Remarks:
Waiver for which the present entry serves as supporting information
Qualifier:
according to guideline
Guideline:
OECD Guideline 111 (Hydrolysis as a Function of pH)
Version / remarks:
Expert Statement displaying why a study according to OECD 111 cannot be performed
Deviations:
not applicable
GLP compliance:
not specified
Specific details on test material used for the study:
STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: At 4°C ± 4°C , in the dark
- Safety Precautions: Routine safety and hygienic procedures
Radiolabelling:
no
Analytical monitoring:
yes
Validity criteria fulfilled:
not applicable
Conclusions:
Solubility and analytical investigations were performed in a scientifically reasonable and well documented manner in order to assess the possibility / feasibility to perform a hydrolysis study according to OECD 111 as stipulated under REACH for registrations > 10 tpa. The results of the experiments indicated that reproducible analytical results could only be obtained in absence of water. This could be traced back either to the very low solubility or to the stability of the test item in water.
A study to investigate the hydrolytic properties of the test item cannot be performed. Regarding the estimated water solubility of 1.171*10-8 mg/L (at 25°C) no analytical method with the appropriate sensitivity is available or could be developed. Moreover, it can be assumed that only a negligible portion of the test item will enter the aquatic environment as soluble substance and hence the impact on the aquatic environment was considered to be of low extent.
Hence, it can be concluded that hydrolysis testing is neither technically feasible nor required.
Executive summary:

The feasibility of a hydrolysis study with the test item was assessed based on the performed tests. As a consequence of the very low water solubility of the test item a solubility test was performed using different solvents to determine the appropriate solvent for the preparation of the stock solution and the sample solution. In a second step, the analytical behaviour of the test item was investigated in order to obtain an analytical method for the analysis of the sample solution with an appropriate sensitivity considering the potential amount of the test item in the aqueous test solution.

The results of the experiments indicated that reproducible analytical results could only be obtained in absence of water. This could be traced back either to the very low solubility or to the stability of the test item in water.

A study to investigate the hydrolytic properties of the test item cannot be performed. Regarding the estimated water solubility of  1.171*10-8 mg/L (at 25°C) no analytical method with the appropriate sensitivity is available or could be developed. Moreover, it can be assumed that only a negligible portion of the test item will enter the aquatic environment as soluble substance and hence the impact on the aquatic environment was considered to be of low extent.

Hence, it can be concluded that hydrolysis testing is neither technically feasible nor required.

Endpoint:
hydrolysis
Type of information:
experimental study
Adequacy of study:
other information
Study period:
2015-02-18 - 2015-03-09
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Reason / purpose for cross-reference:
read-across source
Remarks:
Waiver for which the present entry serves as supporting information
Qualifier:
no guideline available
Principles of method if other than guideline:
In preparation for a hydrolysis study to be conducted under GLP, a solvent screening to find accceptable solvent conditions was conducted. Method: NMR measurement
GLP compliance:
not specified
Remarks:
Available Information: QM-system: DIN EN ISO/IEC 17025 / DAkkS Deutsche Akkreditierungsstelle
Radiolabelling:
no
Analytical monitoring:
yes
Details on sampling:
See "any other information on materials and methods"
Buffers:
none
Details on test conditions:
See "any other information on materials and methods"
Positive controls:
no
Negative controls:
no
Preliminary study:
Result
In our experiments no suitable solvent system for studying the hydrolysis by in-situ NMR was found. Even at very low concentrations such as 0.033% (w/w) a precipitate was formed. Furthermore the sensitivity of the 31P-NMR measurement is not high enough to observe any resonances.
Our result is in good agreement with the statement in the product data sheet of the customer in which the product is described as insoluble in water.
Validity criteria fulfilled:
not applicable
Conclusions:
The present screening study was conducted in order to find acceptable solvent conditions in preparation for a hydrolysis study to be conducted under GLP. The study was well designed and sufficiently documented, so the results can be considered as sufficiently reliable to assess the feasibility of a hydrolysis study. No suitable solvent system for studying the hydrolysis by in-situ NMR was found. Even at very low concentrations such as 0.033% (w/w) a precipitate was formed. Furthermore the sensitivity of the 31P-NMR measurement is not high enough to observe any resonances. Hence, a hydrolysis study is not considered to be technically feasible.
Executive summary:

In preparation for a hydrolysis study to be conducted under GLP, a solvent screening to find acceptable solvent conditions was conducted. No suitable solvent system for monitoring the hydrolysis of 4,8-dicyclohexyl-6-hydroxy-2,10-dimethyl-12H-dibenzo[d,g][1,3,2]dioxaphosphocin was found. A hydrolysis study is not considered to be technically feasible.

Description of key information

Hydrolysis testing is neither technically feasible nor required. A study to investigate the hydrolytic properties of the test item cannot be performed. Regarding the estimated water solubility of  1.171*10exp(-8) mg/L (at 25°C) no analytical method with the appropriate sensitivity is available or could be developed. Moreover, it can be assumed that only a negligible portion of the test item will enter the aquatic environment as soluble substance and hence the impact on the aquatic environment was considered to be of low extent. Also, no suitable solvent for hydrolysis study (in situ NMR) of 4,8-dicyclohexyl-6-hydroxy-2,10-dimethyl-12H-dibenzo[d,g][1,3,2]dioxaphosphocin was found.

Key value for chemical safety assessment

Additional information