Oligomerisation products of alpha-pinene and beta-pinene

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Study period:

2018-04-10

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:

iSafeRat® High-Accuracy-Quantitative Structure-Activity Relationship (HA-QSAR) based on a holistic approach for predicting physicochemical and ecotoxicological endpoints: Water solubility.

1. SOFTWARE
iSafeRat® toolbox – in Silico Algorithms For Environmental Risk And Toxicity version 2.2

2. MODEL (incl. version number)
iSafeRat® holistic HA-QSAR v1.8

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
logKOW of the constituents predicted using the iSafeRat® Log KOW module with the molecular structure (SMILES code) as the input (see attached QPRF).

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See attached QMRF

5. APPLICABILITY DOMAIN
See attached QPRF

6. ADEQUACY OF THE RESULT
See attached QPRF

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

yes

Remarks:

QSAR model

Principles of method if other than guideline:

The purpose of the in silico study was to determine the water solubility of test item in pure water at 25°C. The determination was performed using a regression method in which validated log KOW values are plotted against the log of sub-cooled liquid water solubility from studies of high quality. These have been carried out using one of the methods recommended in the OECD guideline 105 or an adaptation of these.

GLP compliance:

no

Type of method:

other: QSAR

Specific details on test material used for the study:

Not relevant.

Key result

Water solubility:

1.73 µg/L

Conc. based on:

test mat.

Temp.:

25 °C

pH:

7

Remarks on result:

other: 95%CL: 1.58-1.90 µg/L

Details on results:

The log KOW used as the descriptor for this prediction does not fall within the descriptor domain of the model between a log KOW of 1.25 to 7.41. Therefore the prediction is considered as an extrapolation.
See QPRF for details.

Conclusions:

The water solubility of the test item was predicted as 1.73 µg/L at 25°C. 95% confidence interval (α = 0.05): 1.58 – 1.90 µg/L.

Executive summary:

A Quantitative Structure-Property Relationship (QSPR) model was used to calculate the water solubility of the test item, dimers of alpha-pinene. This QSPR model has been validated as a QSAR model to be compliant with the OECD recommendations for QSAR modeling (OECD, 2004) and predicts the endpoint value which would be expected when testing the substance under experimental conditions in a laboratory following the Guideline for Testing of Chemicals No. 105, "Water Solubility". The criterion predicted was the solubility in water in mol.L^-1, converted to mg.L^-1.

The purpose of the in silico study was to determine the water solubility of the test item in pure water at 25°C. The determination was performed using a regression method in which validated log K_OW values are plotted against the log of sub-cooled liquid water solubility from studies of high quality. These have been carried out using one of the methods recommended in OECD guideline 105 or an adaptation of these.

The test item falls within the applicability domain of the model except for the descriptor. Due to the high log K_OW value, the prediction for water solubility is considered as an extrapolation. However the predicted is still considered as reliable since the other validity criteria are satisfied. The water solubility of the test item was predicted as 1.73 µg/L at 25°C. 95% confidence interval (α = 0.05): 1.58 – 1.90 µg/L.

Reference 2

Endpoint:

water solubility

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Study period:

2018-04-10

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:

iSafeRat® High-Accuracy-Quantitative Structure-Activity Relationship (HA-QSAR) based on a holistic approach for predicting physicochemical and ecotoxicological endpoints: Water solubility.

1. SOFTWARE
iSafeRat® toolbox – in Silico Algorithms For Environmental Risk And Toxicity version 2.2

2. MODEL (incl. version number)
iSafeRat® holistic HA-QSAR v1.8

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
logKOW of the constituents predicted using the iSafeRat® Log KOW module with the molecular structure (SMILES code) as the input (see attached QPRF).

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See attached QMRF

5. APPLICABILITY DOMAIN
See attached QPRF

6. ADEQUACY OF THE RESULT
See attached QPRF

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

yes

Remarks:

QSAR model

Principles of method if other than guideline:

The purpose of the in silico study was to determine the water solubility of test item in pure water at 25°C. The determination was performed using a regression method in which validated log KOW values are plotted against the log of sub-cooled liquid water solubility from studies of high quality. These have been carried out using one of the methods recommended in the OECD guideline 105 or an adaptation of these.

GLP compliance:

no

Type of method:

other: QSAR

Specific details on test material used for the study:

Not relevant.

Key result

Water solubility:

1.73 µg/L

Conc. based on:

test mat.

Temp.:

25 °C

pH:

7

Remarks on result:

other: 95%CL: 1.58-1.90 µg/L

Details on results:

The log Kow used as the descriptor for this prediction does not fall within the descriptor domain of the model between a log KOW of 1.25 to 7.41. Therefore the prediction is considered as an extrapolation.
See QPRF for details.

Conclusions:

The water solubility of the test item was predicted as 1.73 µg/L at 25°C. 95% confidence interval (α = 0.05): 1.58 – 1.90 µg/L.

Executive summary:

A Quantitative Structure-Property Relationship (QSPR) model was used to calculate the water solubility of the test item, dimers of beta-pinene. This QSPR model has been validated as a QSAR model to be compliant with the OECD recommendations for QSAR modeling (OECD, 2004) and predicts the endpoint value which would be expected when testing the substance under experimental conditions in a laboratory following the Guideline for Testing of Chemicals No. 105, "Water Solubility". The criterion predicted was the solubility in water in mol.L^-1, converted to mg.L^-1.

The purpose of the in silico study was to determine the water solubility of test item in pure water at 25°C. The determination was performed using a regression method in which validated log K_OW values are plotted against the log of sub-cooled liquid water solubility from studies of high quality. These have been carried out using one of the methods recommended in the OECD guideline 105 or an adaptation of these.

The test item falls within the applicability domain of the model except for the descriptor. Due to the high log K_OW value, the prediction for water solubility is considered as an extrapolation. However the predicted is still considered as reliable since the other validity criteria are satisfied. The water solubility of the test item was predicted as 1.73 µg/L at 25°C. 95% confidence interval (α = 0.05): 1.58 – 1.90 µg/L.

Reference 3

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

12 December 2017 - 29 December 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The determination of water solubility was performed using the slow stirring method adapted from OECD Guideline No 123. This study was considered as reliable without restrictions because it was conducted under GLP.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

other: adapted from OECD Guideline 123

Deviations:

no

Principles of method if other than guideline:

In a stirring vessel maintained at 20 +/- 0.5°C, ultra-pure water containing the test item poured into the top of the vessel was slow stirred. The stirring rate was adjusted in order to form a minimal vortex. The aim of this method was to prevent the formation of emulsions when saturating water. Emulsions can be formed with the shake flask method and lead to a solubility overestimation. The water solubility was given by the mass concentration of the substance in water when a plateau is reached as a function of time. Three experiments were performed in the same conditions.

GLP compliance:

yes (incl. QA statement)

Remarks:

2017-01-10

Type of method:

other: slow-stirring method

Key result

Water solubility:

< 5 µg/L

Temp.:

20 °C

pH:

4.5

Remarks on result:

other: Based on three determinations. Corresponding to the analytical method limit quantification.

Main test:

The following table presents the concentrations obtained during the main test for the three vessels:

Sampling date  Vessel 1  Vessel 2  Vessel 3  12/12/17        Beginning of the slow-stirring  20/12/17 10h00  < 5 µg/L  < 5 µg/L  < 5 µg/L  20/12/17 15h00  < 5 µg/L  < 5 µg/L  < 5 µg/L  21/12/17 08h30  < 5 µg/L  < 5 µg/L  < 5 µg/L  21/12/17 14h30  < 5 µg/L  < 5 µg/L  < 5 µg/L  22/12/17 08h00  < 5 µg/L  < 5 µg/L  < 5 µg/L  22/12/17 13h15  < 5 µg/L  < 5 µg/L  < 5 µg/L  26/12/17 09h00  < 5 µg/L  < 5 µg/L  < 5 µg/L  26/12/17 14h20  < 5 µg/L  < 5 µg/L  < 5 µg/L (sample taken at 14h15)

The systems were let to equilibrate up to 14 days but no tests item was detected in the samples. All the samples concentrations were lower than 5

µg/L, which corresponds to the limit of quantification of the analytical method.

The pH values in the systems were measured at the beginning and at the end of the experiments. The pH values were:

- 4.71 for the ultrapure water used for the systems preparation

-  4.58 in vessel 1, 4.36 in vessel 2 and 4.46 in vessel 3 at the end of the experiment.

The pH controlled with the indicator strips for each specimen were 4.5 for all the samples taken from the three vessels.

The temperature variations were included in the range 20°C - 20.3°C.

 

Conclusions:

Based on three determinations with the slow-stirring method the TERPENIC OLIGOMERS solubility in water at 20°C +/- 0.5°C was: < 5 µg/L (corresponding to the analytical method limit of quantification).

Executive summary:

A study was performed to assess the water solubility of the test item TERPENIC OLIGOMERS by the slow stirring method.

Three determinations in ultrapure water were carried out. 1.5 mL of the test item were carefully poured at the top of 600 mL of water thermostated at 20 + 0.5°C. The systems were allowed to equilibrate one week before starting the sampling and up to 14 days. The test item concentrations were monitored by GC-MS after liquid-liquid extraction of the samples with hexane.

The TERPENIC OLIGOMERS solubility in water at 20°C +/- 0.5°C based on three determinations with the slow-stirring method was:

< 5 µg/L (corresponding to the analytical method limit of quantification).

Description of key information

Water solubility of substance Terpenic Oligomers has been determined using a weight-of-evidence approach on data of two of its major constituents: dimer alpha-pinene and dimer beta-pinene.

Water solubilities of dimers were obtained by QSAR using as descriptor the experimental log Kow of Terpenic Oligomers.

The QSAR results were also confirmed by an experimental study conducted on TERPENIC OLIGOMERS at 20°C +/- 0.5°C, where the water solubility was < 5 µg/L (corresponding to the analytical method limit of quantification).

Key value for chemical safety assessment

Water solubility:

1.73 µg/L

at the temperature of:

25 °C

Additional information

Water solubilities of alpha-pinene dimers and beta-pinene dimers are predicted as 1.73 µg/L at 25°C [95% confidence interval (α = 0.05) = 1.58 – 1.90 µg/L].

Also, a study was performed to measure the water solubility of TERPENIC OLIGOMERS with the slow-stirring method according to a method adapted from OECD guideline 123. As the results were obtained under GLP without deviation, they were considered as valid and reliable without restriction.