Silicon dioxide

Solubility in organic solvents / fat solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

solubility in organic solvents / fat solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

03.11.2017 - 10.11.2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 105 resp. EU A.6

Deviations:

yes

Remarks:

the pH value in ethanol solutions was not determined

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Designation in Test Facility: 17061303G
Date of Receipt: 13. Jun. 2017
Condition at Receipt: room temperature, in proper conditions
Name: Sylodent VP 5
Batch no.: 1503257003
Appearance: white powder
Composition: >99.8 % SiO2
CAS No.: 7631-86-9
EINECS-No.: 231-545-4
Molecular formula: SiO2
Molecular weight: 60.08 g/mol
Purity: >99.8 %
Homogeneity: homogeneous
Production date: 18. Jan. 2016
Expiry date: Aug. 2018
Storage: 20 ± 5 °C

Key result

Medium:

ethanol

Solubility:

< 0.49 mg/L

Temp.:

20 °C

Details on results:

The concentration of the test item Sylodent VP 5 in ethanol using ICP-OES was calculated based on the LOQ of Silicon (227 μg/L) and the Silicon content in the test item as:
< 0.49 mg/L at 20.0 ± 0.5 °C

< 0.49 mg/L at 20.0 ± 0.5 °C

< 0.49 * 10^-3 kg/m³ (SI units).

Conclusions:

The concentration of the test item Sylodent VP 5 in ethanol using ICP-OES was calculated based on the LOQ of Silicon (227 μg/L) and the Silicon content in the test item as:
< 0.49 mg/L at 20.0 ± 0.5 °C

Executive summary:

The solubility of the test item Sylodent VP 5 in ethanol was determined by measurement of the Silicon concentration in the filtrated test solutions using two different methods, ICPOES and photometry.

The preliminary test which is described in the guideline was not performed. After consultation with the sponsor the flask method was used.

In the main test, 50 g/L test item in water were used for the test. Six individual flasks (flasks 1A - 1C and 2 – 4) were prepared. Five vessels (blank, flasks 1C (for the sampling point 72 h) and 2 – 4) were set onto the shaking apparatus immediately. After 24 ± 2 hours, flask 1B (for the sampling point 48 h) and after further 24 ± 2 hours, flask 1A (for the

sampling point 24 h) were set on the shaker and all flasks were shaken for further 24 ± 2 hours at room temperature (20.0 ± 0.5 °C). Then, flasks 1A - 1C were taken from the shaker, samples were taken, membrane filtrated and analysed for Silicon via ICP-OES on day 3 (flasks 1A, 1B, 1C). As the measured value lay below the LOQ of Si (< 227 μg/L Si) the test was prolonged and the flasks 1A – 1C were measured getting the values for days 4 – 7. The test was finished on day 7 as the measured value lay below the LOQ, too.

Therefore, on the same day 7, flasks 2 – 4 were sampled and analysed for Silicon in the same fashion.

No Tyndall effect (i.e. a laser beam was not scattered when transmitted through the liquid) could be observed indicating that no colloidal dispersed particles were present.

The concentration of the test item Sylodent VP 5 using photometry was calculated based on the LOQ of Silicon (500 μg/L) and the Silicon content in the test item as < 1.07 mg/L.

The concentration of the test item Sylodent VP 5 in ethanol using ICP-OES was calculated based on the LOQ of Silicon (227 μg/L) and the Silicon content in the test item as:

< 0.49 mg/L at 20.0 ± 0.5 °C

< 0.49 * 10^-3 kg/m³ (SI units).

Reference 2

Endpoint:

solubility in organic solvents / fat solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

03.11.2017 - 10.11.2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 105 resp. EU A.6

Deviations:

yes

Remarks:

the pH value in ethanol solutions was not determined

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Designation in Test Facility: 17061303G
Date of Receipt: 13. Jun. 2017
Condition at Receipt: room temperature, in proper conditions
Name: Sylodent VP 5
Batch no.: 1503257003
Appearance: white powder
Composition: >99.8 % SiO2
CAS No.: 7631-86-9
EINECS-No.: 231-545-4
Molecular formula: SiO2
Molecular weight: 60.08 g/mol
Purity: >99.8 %
Homogeneity: homogeneous
Production date: 18. Jan. 2016
Expiry date: Aug. 2018
Storage: 20 ± 5 °C

Key result

Medium:

ethanol

Solubility:

< 0.49 mg/L

Temp.:

20 °C

Details on results:

The concentration of the test item Sylodent VP 5 in ethanol using ICP-OES was calculated based on the LOQ of Silicon (227 μg/L) and the Silicon content in the test item as:
< 0.49 mg/L at 20.0 ± 0.5 °C

< 0.49 mg/L at 20.0 ± 0.5 °C

< 0.49 * 10^-3 kg/m³ (SI units).

Conclusions:

The concentration of the test item Sylodent VP 5 in ethanol using ICP-OES was calculated based on the LOQ of Silicon (227 μg/L) and the Silicon content in the test item as:
< 0.49 mg/L at 20.0 ± 0.5 °C

Executive summary:

The solubility of the test item Sylodent VP 5 in ethanol was determined by measurement of the Silicon concentration in the filtrated test solutions using two different methods, ICPOES and photometry.

The preliminary test which is described in the guideline was not performed. After consultation with the sponsor the flask method was used.

In the main test, 50 g/L test item in water were used for the test. Six individual flasks (flasks 1A - 1C and 2 – 4) were prepared. Five vessels (blank, flasks 1C (for the sampling point 72 h) and 2 – 4) were set onto the shaking apparatus immediately. After 24 ± 2 hours, flask 1B (for the sampling point 48 h) and after further 24 ± 2 hours, flask 1A (for the

sampling point 24 h) were set on the shaker and all flasks were shaken for further 24 ± 2 hours at room temperature (20.0 ± 0.5 °C). Then, flasks 1A - 1C were taken from the shaker, samples were taken, membrane filtrated and analysed for Silicon via ICP-OES on day 3 (flasks 1A, 1B, 1C). As the measured value lay below the LOQ of Si (< 227 μg/L Si) the test was prolonged and the flasks 1A – 1C were measured getting the values for days 4 – 7. The test was finished on day 7 as the measured value lay below the LOQ, too.

Therefore, on the same day 7, flasks 2 – 4 were sampled and analysed for Silicon in the same fashion.

No Tyndall effect (i.e. a laser beam was not scattered when transmitted through the liquid) could be observed indicating that no colloidal dispersed particles were present.

The concentration of the test item Sylodent VP 5 using photometry was calculated based on the LOQ of Silicon (500 μg/L) and the Silicon content in the test item as < 1.07 mg/L.

The concentration of the test item Sylodent VP 5 in ethanol using ICP-OES was calculated based on the LOQ of Silicon (227 μg/L) and the Silicon content in the test item as:

< 0.49 mg/L at 20.0 ± 0.5 °C

< 0.49 * 10^-3 kg/m³ (SI units).