Naphtha (petroleum), steam-cracked, C8-10 aromatic hydrocarbon fraction, alkylated and oligomerised

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study based on accepted scientific standards

Reason / purpose for cross-reference:

reference to same study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Principles of method if other than guideline:

- Principle of test: due to the UVCB characteristic of the test substance with variable solubilities depending on loading, water-accommodated fraction (WAF) were prepared. Water solubility was determined with a loading of 100 mg/L.
- Parameters analysed / observed: Total Organic Carbon (TOC) was analysed in order to quantify the test material. There is no specific analytical method availble for the determination of the complex UVCB test substance.

GLP compliance:

no

Type of method:

flask method

Specific details on test material used for the study:

- Name of test material (as cited in study report): Novares L 100; CAS-no. 71302-83-5 (Hydrocarbons, C9- unsaturated, polymerized)
- Composition of test material, percentage of components: see Section 1.2 Composition
- Lot/batch No.: 24106
- Stability under test conditions: no measured data; based on chemical structure assumed to be stable
- Storage condition of test material: room temperature, exclusion of light

Key result

Water solubility:

1.39 other: mg TOC/L (initial average, n = 3, time 0)

Conc. based on:

test mat.

Loading of aqueous phase:

100 mg/L

Incubation duration:

24 h

Temp.:

20 °C

pH:

ca. 8

Remarks on result:

other: aqueous concentration was determined after filtration of the aqueous phase

Key result

Water solubility:

1.12 other: mg TOC/L (average after storage, n = 3, time 48 h)

Conc. based on:

test mat.

Loading of aqueous phase:

100 mg/L

Incubation duration:

24 h

Temp.:

20 °C

pH:

ca. 8

Remarks on result:

other: aqueous concentration was determined after filtration of the aqueous phase

Details on results:

Solubility data relate to loading of 100 mg TS/L:
Single values (time 0): 1.37, 1.40, 1.39 mg C/L
Single values (time 48 h): 1.09, 1.15, 1.11 mg C/L
Control 0.0 mg C/L
Limit of Quantification: 0.01 mg/L

Conclusions:

The test item L 100 (technical product of the UVCB substance 'Naphtha (petroleum), steam-cracked, C8-10 aromatic hydrocarbon fraction, alkylated and oligomerised') showed a low aqueous solubility. After stirring an amount of 100 mg/L of the test item for 24 hours in a closed vessel, concentration in the aqueous phase (water accommodated fraction) was only 1.39 mg (TOC)/L. Due to the complex composition of the test substance, the aqueous concentration was measured as Total Organic Carbon.

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Principles of method if other than guideline:

- Principle of test: due to the UVCB characteristic of the test substance with variable solubilities depending on loading, water-accommodated fraction (WAF) were prepared. Water solubility was determined with a loading of 100 mg/L.
- Parameters analysed / observed: Total Organic Carbon (TOC) was analysed in order to quantify the test material. There is no specific analytical method availble for the determination of the complex UVCB test substance.

GLP compliance:

no

Type of method:

flask method

Specific details on test material used for the study:

- Name of test material (as cited in study report): Novares L 800; CAS-no. 71302-83-5 (Hydrocarbons, C9- unsaturated, polymerized)
- Composition of test material, percentage of components: see Section 1.2 Composition
- Stability under test conditions: no measured data; based on chemical structure assumed to be stable
- Storage condition of test material: room temperature, exclusion of light

Key result

Water solubility:

0.62 other: mg TOC/L (initial average, n = 3, time 0)

Conc. based on:

test mat.

Loading of aqueous phase:

100 mg/L

Incubation duration:

24 h

Temp.:

20 °C

pH:

ca. 8

Remarks on result:

other: aqueous concentration was determined after filtration of the aqueous phase

Key result

Water solubility:

0.3 other: mg TOC/L (average after storage, n = 3, time 48 h)

Conc. based on:

test mat.

Loading of aqueous phase:

100 mg/L

Incubation duration:

24 h

Temp.:

20 °C

pH:

ca. 8

Remarks on result:

other: aqueous concentration was determined after filtration of the aqueous phase

Details on results:

Solubility data relate to loading of 100 mg TS/L:
Single values (time 0): 0.61, 0.63, 0.62 mg C/L
Single values (time 48 h): 0.33, 0.30, 0.27 mg C/L
Control 0.0 mg C/L
Limit of Quantification: 0.01 mg/L

Conclusions:

The test item L 800 (technical product of the UVCB substance 'Naphtha (petroleum), steam-cracked, C8-10 aromatic hydrocarbon fraction, alkylated and oligomerised') showed a very low aqueous solubility. After stirring an amount of 100 mg/L of the test item for 24 hours in a closed vessel, concentration in the aqueous phase (water accommodated fraction) was only 0.62 mg (TOC)/L. Due to the complex composition of the test substance, the aqueous concentration was measured as Total Organic Carbon.

Reference 3

Endpoint:

water solubility

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

1. SOFTWARE
US EPA (2012 ). Estimation Programs Interface Suite™ (EPI Suite) for Microsoft® Windows, v 4.11. United States Environmental Protection Agency, Washington, DC, USA.

2. MODEL (incl. version number)
Model WATERNT, version 1.01

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
CAS 3910-35-8: c(c(ccc1)C(C2)(C)C)(c1)C2(c(cccc3)c3)C (ECHA's Reference Substance SMILES notation "CC1(C)CC(C)(c2ccccc2)c3ccccc13" results in the same structure)
CAS 6362-80-7: c(cccc1)(c1)C(CC(c(cccc2)c2)=C)(C)C (ECHA's Reference Substance SMILES notation "CC(C)(CC(=C)c1ccccc1)c2ccccc2" results in the same structure)
CAS 6258-73-7: c(cccc1)(c1)C(C=C(c(cccc2)c2)C)(C)C (ECHAs Reference Substance SMILES notation "CC(C)(C=C(C)c1ccccc1)c2ccccc2" results in the same structure)

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
- Defined endpoint: yes, water solubility at 25 °C
- Unambiguous algorithm: yes
- Defined domain of applicability: see under Attached justification

5. APPLICABILITY DOMAIN
- Descriptor domain: specified by molecular fragments
- Similarity with analogues in the training set: yes, substances with similar fragments (aromatic, aliphatic, olefinic)
- Other considerations: for more detailed information see under Attached justification

6. ADEQUACY OF THE RESULT
Result of the prediction is used as information for the dimeric constituents (dimers of C8-10 aromatic fraction) of the registration substance 'Naphtha (petroleum), steam-cracked, C8-10 aromatic hydrocarbon fraction, alkylated and oligomerised' and as weight of evidence information on the water solubility of the substance.

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Software tool(s) used including version: US EPA (2012 ). Estimation Programs Interface Suite™ (EPI Suite) for Microsoft® Windows, v 4.11. United States Environmental Protection Agency, Washington, DC, USA.
- Model(s) used: Model WATERNT, version 1.01
- Model description: see field 'Justification for non-standard information' and 'Attached justification'
- Justification of QSAR prediction: see field 'Justification for type of information' and 'Attached justification'
The water solubility of three different compounds was calculated that are constituents of the dimeric component of 'Naphtha (petroleum), steam-cracked, C8-10 aromatic hydrocarbon fraction, alkylated and oligomerised'. In addition, the water solubility of these substances was also estimated using the program WSKOWWIN, that is also included in US EPA EPI Suite.

Type of method:

other: calculation method (fragments)

Key result

Water solubility:

0.034 mg/L

Conc. based on:

test mat.

Temp.:

25 °C

Remarks on result:

other: substance 1,1,3-trimethyl-3-phenylindan (CAS no. 3910-35-8), calculated value (program WATERNT)

Remarks:

calculated value (program WSKOWWIN): 0.2503 mg/L

Key result

Water solubility:

0.038 mg/L

Conc. based on:

test mat.

Temp.:

25 °C

Remarks on result:

other: substance 1,1'-(1,1-dimethyl-3-methylene-1,3-propanediyl)bisbenzene (CAS no. 6362-80-7), calculated value (program WATERNT)

Remarks:

calculated value (program WSKOWWIN): 0.0772 mg/L

Key result

Water solubility:

0.082 mg/L

Conc. based on:

test mat.

Temp.:

25 °C

Remarks on result:

other: substance 1,1'-(1,3,3-trimethylprop-1-ene-1,3-diyl)dibenzene (CAS no. 6258-72-7), calculated value (program WATERNT)

Remarks:

calculated value (program WSKOWWIN): 0.0901 mg/L

Conclusions:

The estimated values for water solubility of the three constituents of the dimeric component of the substance 'Naphtha (petroleum), steam-cracked, C8-10 aromatic hydrocarbon fraction, alkylated and oligomerised' range from ca. 0.0339 to ca. 0.0820 mg/L (program WATERNT). With the program WSKOWWIN, water solubilities between 0.2503 and 0.0901 mg/L were estimated. These values are clearly below 1 mg/L. The results of the program WATERNT are closer together (0.0339 to 0.0820 mg/L, overall below 0.1 mg/L) compared to the results of the program WSKOWWIN (0.2509 to 0.0772 mg/L). The water solubility of the indan derivative (0.2503 mg/L) is distinctly higher than the water solubility of the 2-ene (0.0901 mg/L) and the 1-ene (0.0772 mg/L) olefinic derivative. WATERNT results increase systematically from the indan over the 1-ene and 2-ene olefinic derivative, while results of the WSKOWWIN program follow in the order of the calculated log Kow values (indan derivative < 2-ene olefinic derivative < 1-ene olefinic derivative).

Reference 4

Endpoint:

water solubility

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

1. SOFTWARE
US EPA (2012 ). Estimation Programs Interface Suite™ (EPI Suite) for Microsoft® Windows, v 4.11. United States Environmental Protection Agency, Washington, DC, USA.

2. MODEL (incl. version number)
Model WATERNT, version 1.01

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
CAS 41906-71-2: c(c(ccc1)C(C2)(CC(c(cccc3)c3)(C)C)C)(c1)C2(c(cccc4)c4)C (ECHA's Reference Substance SMILES notation "CC(C)(CC1(C)CC(C)(c2ccccc2)c3ccccc13)c4ccccc4" results in the same structure)
CAS 62604-62-0: c(cccc1)(c1)C(CC(c(cccc2)c2)(CC(c(cccc3)c3)=C)C)(C)C (ECHA's Reference Substance SMILES notation "CC(C)(CC(C)(CC(=C)c1ccccc1)c2ccccc2)c3ccccc3" results in the same structure)
CAS 19303-34-5: c(cccc1)(c1)C(C=C(c(cccc2)c2)C)(CC(c(cccc3)c3)(C)C)C (ECHAs Reference Substance SMILES notation "CC(C)(CC(C)(C=C(C)c1ccccc1)c2ccccc2)c3ccccc3" results in the same structure)

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
- Defined endpoint: yes, water solubility at 25 °C
- Unambiguous algorithm: yes
- Defined domain of applicability: see under Attached justification

5. APPLICABILITY DOMAIN
- Descriptor domain: specified by molecular fragments
- Similarity with analogues in the training set: yes, substances with similar fragments (aromatic, aliphatic, olefinic)
- Other considerations: for more detailed information see under Attached justification

6. ADEQUACY OF THE RESULT
Result of the prediction is used as information for the trimeric constituents (trimers of C8-10 aromatic fraction) of the registration substance 'Naphtha (petroleum), steam-cracked, C8-10 aromatic hydrocarbon fraction, alkylated and oligomerised' and as weight of evidence information on the water solubility of the substance.

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Software tool(s) used including version: US EPA (2012 ). Estimation Programs Interface Suite™ (EPI Suite) for Microsoft® Windows, v 4.11. United States Environmental Protection Agency, Washington, DC, USA.
- Model(s) used: Model WATERNT, version 1.01
- Model description: see field 'Justification for non-standard information' and 'Attached justification'
- Justification of QSAR prediction: see field 'Justification for type of information' and 'Attached justification'
The water solubility of three different compounds was calculated that are constituents of the trimeric component of 'Naphtha (petroleum), steam-cracked, C8-10 aromatic hydrocarbon fraction, alkylated and oligomerised'. In addition, the water solubility of these substances was also estimated using the program WSKOWWIN, that is also included in US EPA EPI Suite.

Type of method:

other: calculation method (fragments)

Key result

Water solubility:

0.011 µg/L

Conc. based on:

test mat.

Temp.:

25 °C

Remarks on result:

other: substance 1,3-dimethyl-1-(2-methyl-2-phenylpropyl)-3-phenylindan (CAS no. 41906-71-2), calculated value (program WATERNT)

Remarks:

calculated value (program WSKOWWIN): 0.1248 µg/L

Key result

Water solubility:

0.013 µg/L

Conc. based on:

test mat.

Temp.:

25 °C

Remarks on result:

other: substance 1,1',1''-(1,1,3-Trimethyl-5-methylenepentane-1,3,5-triyl)tribenzene (CAS no. 62604-62-0), calculated value (program WATERNT)

Remarks:

calculated value (program WSKOWWIN): 0.03814 µg/L

Key result

Water solubility:

0.027 µg/L

Conc. based on:

test mat.

Temp.:

25 °C

Remarks on result:

other: substance 1,1',1''-(1,3,5,5-tetramethylpent-1-ene-1,3,5-triyl)tribenzene (CAS no. 19303-34-5), calculated value (program WATERNT)

Remarks:

calculated value (program WSKOWWIN): 0.04451 µg/L

Conclusions:

The estimated values for water solubility of the three constituents of the trimeric component of the substance 'Naphtha (petroleum), steam-cracked, C8-10 aromatic hydrocarbon fraction, alkylated and oligomerised' (NAF-AO) range from ca. 0.0113 to ca. 0.0273 µg/L (program WATERNT). With the program WSKOWWIN, water solubilities between 0.1248 and 0.0381 µg/L were estimated. These values are in the range of ng/L and clearly below 1 µg/L. The results of the program WATERNT are closer together (0.0113 to 0.0273 µg/L, overall below ca. 30 ng/L) compared to the results of the program WSKOWWIN (0.0381 to 0.125 µg/L). WATERNT results increase systematically from the indan over the 1-ene to the 2-ene olefinic derivative, while results of the WSKOWWIN program follow in the order of the calculated log Kow values (indan derivative < 2-ene olefinic derivative < 1-ene olefinic derivative).
Altogether, the water solubilities of the trimeric constituents of NAF-AO are estimated to be very low (below 50 ng/L except one value).

Description of key information

Due to the nature of the substance ‘Naphtha (petroleum), steam-cracked, C8-10 aromatic hydrocarbon fraction, alkylated and oligomerised’ (NAF-AO) (see Chapter 1) that is produced as different technical products, there is a small range of water solubilities. The water solubility of two different products (Novares L 100 and Novares L 800) was determined to be ca. 1.4 mg TOC/L and ca. 0.6 mg TOC/L, respectively.

Estimates of water solubility by (Q)SAR calculations for constituent of the dimeric and the trimeric component of NAF-AO resulted in values between 0.0339 to 0.0820 mg/L for the dimeric constituents and between 0.0113 to ca. 0.0273 µg/L for the trimeric constituents.

Estimated aqueous solubilities for individual constituents are much lower than the solubility experimentally determined for the UVCB substance as such.

Key value for chemical safety assessment

Water solubility:

1 mg/L

at the temperature of:

20 °C

Additional information

The water solubility of NAF-AO was determined in a study according to OECD TG 105 for two different product types of NAF-AO. Due to the complex composition of the UVCB substance, no specific analytical method for the analysis of the complete substance is available. Instead, the parameter Total Organic Carbon (TOC) was analysed. As the amount of solute in an aqueous solution is dependent on the loading of the solution, water accommodated fractions (WAF) were prepared. At a loading of 100 mg test material/L, the concentration of NAF-AO (measured as TOC) was 1.39 mg TOC/L for the technical product Novares L 100 and 0.62 mg TOC/L for the technical product Novares L 800.

The substance NAF-AO is composed of dimers, trimers, and higher (n ≥ 4) oligomers of the monomeric C8-10 aromatic hydrocarbon fraction. Due to differences in their size and structure, the water solubility of dimeric, trimeric, and oligomeric constituents will be quite different and can span several orders of magnitude.

In order to obtain information on individual constituents of NAF-AO, water solubilities of three dimeric and three trimeric constituents of NAF-AO were estimated by (Q)SAR calculation. Water solubility was estimated using two program components of the program US EPA EPI Suite (WATERNT vers. 1.01 and WSKOWWIN/WSKOW ver. 1.42). Results of the program WATERNT ranged from 0.039 to 0.082 mg/L for the dimers and from 0.0127 µg/L to 0.0273 µg/L for the trimers. With the program WSKOWWIN slightly higher result were obtained (dimers from 0.0772 mg/L to 0.2503 mg/L; trimers from 0.0381 µg/L to 0.1218 µg/L).

Obviously, water solubilities of individual neat constituents of NAF-AO are estimated to be much lower than the water solubility that was determined for the substance NAF-AO as such. This is considered to be caused by the complex composition of the material. The many substances included in the process of dissolution seem to increase the water solubility of the total material compared to single compound.

Estimated water solubilities of dimeric and trimeric constituents of NAF-AO differ by about three orders of magnitude. Water solubility of oligomers will be even lower. It can be assumed that the water solubility of technical products with a higher portion of trimers and higher oligomers will be reduced compared to products with less trimers and oligomers (see water solubility of Novares L 100 and Novares L 800).

For the chemical safety assessment, a key value for water solubility of the substance NAF-AO has to be specified. This key value will be based on experimentally determined data. The arithmetic mean of the two studies with Novares L 100 and Novares L 800 is used as key value (1.0 mg/L).

This is considered to be an upper limit. The water solubility of products with a higher portion of trimers and oligomers than Novares L 100 and Novares L 800 will very likely have a lower water solubility.