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Water solubility

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Endpoint:
transformation / dissolution of metals and inorganic metal compounds
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Jan. 8 - Feb. 14, 2019 (experimental phase)
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Series on Testing and Assessment No. 29 (23-Jul-2001): Guidance document on transformation/dissolution of metals and metal compounds in aqueous media
Version / remarks:
2001
GLP compliance:
yes (incl. certificate)
Type of method:
flask method
Specific details on test material used for the study:
Name High Surface Precipitated SiO2
Batch no. F7SCF01
Appearance white powder
Composition SiO2; Na2SO4
CAS No. 7631-86-9 (112926-00-8)
EC-No. 231-545-4
Key result
Type of test:
full transformation/dissolution test - metals and sparingly soluble metal compounds
Mean dissolved conc.:
990.5 µg/L
Element analysed:
Si
Loading of aqueous phase:
1 000 µg/L
Incubation duration:
28 d
Test conditions:
20.6 - 21.9 °C, ph 8.5
Remarks on result:
other: mean value of days 4 – 28

The determined values of the dissolution test are presented in attached table 3.2-a together with the measured concentrations in each flask plotted versus time.

No linear dependency of measured concentrations on time was observed. On day 4, the plateau was considered as reached as the difference between the measured concentrations on day 4 and day 28 was lower than 15 %. As no linear dependency of measured concentrations on time was observed, the first order model was used for the determination of kinetic. The linear dependency of “ln (A / (A – Ct))” on time was observed after 2 h – 1 d only. The first order constant “k” was calculated as 1.64 1/d (mean value of the flasks 3 – 5) with the RSD of 8.7%

The conditions RSD < 10 % (within-vessel) and < 20 % (between-vessel) were fulfilled at each sampling point in all flasks. Therefore, the mean value from the flasks 3 – 5 (1 mg/L nominal load, mean value of days 4 – 28) was stated as the result of the study: 990.5 µg/L Test Item at 20.6 – 21.9 °C.

The test item was completely dissolved in pH 8.5 buffer solution (99 % dissolved part of the nominal load 1000 µg/L).

Conclusions:
990.5 µg/L (c. 99%) of the test Item were dissolved in pH 8.5 buffer solution at 20.6 – 21.9 °C (1 mg/L nominal load, mean value of days 4 – 28).
Executive summary:

This study was performed in order to determine the transformation and/or dissolution of High Surface Precipitated SiO2 via measurement of Silicon (Si) per ICP-OES in aqueous media.

Endpoint:
transformation / dissolution of metals and inorganic metal compounds
Type of information:
experimental study
Adequacy of study:
key study
Study period:
March 14, 2019 (experimental phase)
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Series on Testing and Assessment No. 29 (23-Jul-2001): Guidance document on transformation/dissolution of metals and metal compounds in aqueous media
Version / remarks:
2001
GLP compliance:
yes (incl. certificate)
Type of method:
flask method
Specific details on test material used for the study:
nano particular colloidal silica dispersed in water
CAS No. 7631-86-9
EC-No. 231-545-4
pH 8.5 – 9.2 in dispersion
Key result
Type of test:
full transformation/dissolution test - metals and sparingly soluble metal compounds
Mean dissolved conc.:
557.8 µg/L
Element analysed:
Si
Loading of aqueous phase:
1 000 µg/L
Incubation duration:
28 d
Test conditions:
21 - 22 °C, ph 8.5
Remarks on result:
other: mean value of days 7 – 28

The determined values of the dissolution test are presented in attached table 3.2-a together with the measured concentrations in each flask plotted versus time.

No linear dependency of measured concentrations on time was observed. On day 4, the plateau was considered as reached as the difference between the measured concentrations on day 4 and day 28 was lower than 15 %. As no linear dependency of measured concentrations on time was observed, the first order model was used for the determination of kinetic. The linear dependency of “ln (A / (A – Ct))” on time was observed after 2 h – 1 d only. The first order constant “k” was calculated as 1.64 1/d (mean value of the flasks 3 – 5) with the RSD of 8.7%

The conditions RSD < 10 % (within-vessel) and < 20 % (between-vessel) were fulfilled at each sampling point in all flasks. Therefore, the mean value from the flasks 3 – 5 (1 mg/L nominal load, mean value of days 4 – 28) was stated as the result of the study: 990.5 µg/L Test Item at 20.6 – 21.9 °C.

The test item was completely dissolved in pH 8.5 buffer solution (99 % dissolved part of the nominal load 1000 µg/L).

Conclusions:
990.5 µg/L (c. 99%) of the test Item were dissolved in pH 8.5 buffer solution at 20.6 – 21.9 °C (1 mg/L nominal load, mean value of days 4 – 28).
Executive summary:

This study was performed in order to determine the transformation and/or dissolution of High Surface Precipitated SiO2 via measurement of Silicon (Si) per ICP-OES in aqueous media.

Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
26.09.2016-04.10.2016
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
Qualifier:
equivalent or similar to
Guideline:
EU Method A.6 (Water Solubility)
GLP compliance:
yes (incl. certificate)
Type of method:
flask method
Specific details on test material used for the study:
Name: AEROSIL® OX 50 (UB 862812)
Batch no.: 155111045
Appearance: white powder
Composition: Silicon dioxide, chemically prepared
CAS No.: 112945-52-5
EINECS-No.: 231-545-4
Molecular formula: SiO2
Molecular weight: 60.1 g/mol
Purity: > 99.8% (ISO 3262-20)
Homogeneity: homogeneous
Production date: 10. Nov. 2015
Expiry date: 09. Nov. 2017
Specific surface area: 44 m2/g
Storage: Room Temperature (20 ± 5°C)
Key result
Water solubility:
>= 111.7 - <= 124 mg/L
Conc. based on:
test mat.
Incubation duration:
>= 1 - <= 8 d
Temp.:
20 °C
pH:
5
Details on results:
At the plateau, the concentration of the test item AEROSIL® OX 50 (UB 862812) using
ICP-OES was calculated based on the measured Silicon concentrations in flasks 1A-C
(mean, 6 – 8 d) and 2 – 4 and the Silicon content in the test item as 111.7 ± 1.7 mg/L.
Additionally, the concentration of Silicon in the filtrated solutions (flasks 1C and flasks 2 –
4) was determined using photometry for comparison of the results with the first measurement
via ICP-OES. The mean concentration of the test item AEROSIL® OX 50 (UB
862812) in the four replicates was 124.0 ± 1.7 mg/L.
The determination of the solubility of the test item in water using two different methods
(ICP-OES and photometry) showed similar results. The solubility of the test item was stated
as
117.9 ± 6.7 mg/L at 20.0 ± 0.5 °C
(mean value of two methods ± standard deviation of eight individual values (six vessels),
nominal concentration 50 g/L)

117.9 ± 6.7 mg/L at 20.0 ± 0.5 °C

= 1.179 ± 0.067 * 10-1 kg/m3 (SI units)

Conclusions:
The determination of the solubility of the test item in water using two different methods
(ICP-OES and photometry) showed similar results. The water solubility of the test item was
stated as 117.9 ± 6.7 mg/L (mean value of two methods).
Executive summary:

The solubility of the test item AEROSIL® OX 50 (UB 862812) in water was determined by

measurement of the Silicon concentration in the filtrated test solutions using two different

methods, ICP-OES and photometry. Potentially available undissolved particles in the filtrated

test item solutions were measured using Tyndall device.

The solubility of the test item was provided by the sponsor to be > 10 mg/L and therefore

the preliminary test described in the guideline was not performed. Following the guideline,

the flask method was used for the determination of the solubility of the test item in water.

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). Because of an upward tendency in the three values on day 3 the

test was prolonged. Due to a difference of less than 15 % in the concentrations on days 7

and 8 and no upward tendency in the last three values, the test was finished.

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.

All measurements using Tyndall device lay below LOD of the method (< 2 mg/L particle

concentration).

At the plateau, the concentration of the test item AEROSIL® OX 50 (UB 862812) using

ICP-OES was calculated based on the measured Silicon concentrations in flasks 1A-C

(mean, 6 – 8 d) and 2 – 4 and the Silicon content in the test item as 111.7 ± 1.7 mg/L.

Additionally, the concentration of Silicon in the filtrated solutions (flasks 1C and flasks 2 –

4) was determined using photometry for comparison of the results with the first measurement

via ICP-OES. The mean concentration of the test item AEROSIL® OX 50 (UB

862812) in the four replicates was 124.0 ± 1.7 mg/L.

The determination of the solubility of the test item in water using two different methods

(ICP-OES and photometry) showed similar results. The solubility of the test item was stated

as

117.9 ± 6.7 mg/L at 20.0 ± 0.5 °C

= 1.179 ± 0.067 * 10-1 kg/m3 (SI units)

(mean value of two methods ± standard deviation of eight individual values (six vessels),

nominal concentration 50 g/L)

Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
12.01.2016-11.02.2016
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
Qualifier:
equivalent or similar to
Guideline:
EU Method A.6 (Water Solubility)
GLP compliance:
yes (incl. certificate)
Type of method:
flask method
Specific details on test material used for the study:
Name: AEROSIL® 200 Pharma
Lot nos.: 155070414 (15121707G), 155101214 (15121708G), 155120414 (15121709G), 155120514 (15121710G), 155120614 (15121711G)
Appearance: white powder
Composition: Silicon dioxide, chemically prepared
Purity 99.0-100.5% (acc. Ph.Eur., USP/NF; JP)
Homogeneity: homogeneous
Expiry dates: 03. Jul. 2017 (15121707G) 11. Oct. 2017 (15121708G), 03. Dec. 2017 (15121709G), 04. Dec. 2017 (15121710G), 05. Dec. 2017 (15121711G)
Specific surface area: 202 m2/g (15121707G), 210 m2/g (15121708G), 203 m2/g (15121709G), 208 m2/g (15121710G), 206 m2/g (15121711G)
Storage: Room Temperature (20 ± 5°C)
CAS No. 112945-52-5
Molecular formula: SiO2
Molecular weight: 60 g/mol
Key result
Water solubility:
>= 193.5 - <= 209.3 mg/L
Conc. based on:
test mat.
Incubation duration:
>= 1 - <= 4 d
Temp.:
20 °C
pH:
>= 5 - <= 6
Details on results:
The determination of the solubility of the test items in water using two different methods
(ICP-OES and photometry) showed similar results. The total mean of the water solubility of the test items was
stated as 201.6 ± 5.3 mg/L (total mean value of two methods and five lots).
Conclusions:
The determination of the solubility of the test items in water using two different methods
(ICP-OES and photometry) showed similar results. The total mean of the water solubility of the test items was
stated as 201.6 ± 5.3 mg/L (mean value of two methods).
Executive summary:

The solubility of AEROSIL® 200 Pharma (5 lots) in water was determined by

measurement of the Silicon concentrations in filtrated test solutions with the nominal concentration

50 g/L. The content of Silicon in the test item was calculated from the molecular

formula as 46.75 %.

Two different analytical methods were used for the determination of Silicon in the test item

solutions. The measurements from the flasks 1A-C and 2 – 4 were used in the calculation

of the mean. Potentially available undissolved particles in the filtrated test item solutions

were measured using Tyndall device.

Using ICP-OES, the water solubility of the test item lay in the range of 193.5 – 209.3 mg/L

(all lots). Additionally, the concentration of Silicon in the filtrated solutions (flasks 1C, 2 – 4)

was determined via photometry. The concentration of the test item was calculated based

on the measured Silicon concentrations and the Silicon content in the test item (46.75 %)

and lay in the range of 195.3 – 208.1 mg/L (five lots).

Mean of all lots was stated as 201.6 ± 5.3 mg/L (relative standard deviation 2.6 %).

Therefore, determination of the solubility of the test item in water using two different methods

(ICP-OES and photometry) showed similar results for each lot.

The filtrated solutions of the test items 15121707G, 15121708G and 15121709G were

measured via Tyndall device after storage of the solutions for approx. 3 weeks in the

fridge. The other samples (15121710G and 15121711G) were stored at room temperature

and filtrated before measurement. All measurements using Tyndall device lay below the

LOD of the method (< 3 mg/L particle concentration).

No observations arousing doubts concerning the accuracy of the results and the validity of

the study were made.

Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
08.03.2018 - 18.05.2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
Qualifier:
equivalent or similar to
Guideline:
EU Method A.6 (Water Solubility)
GLP compliance:
yes (incl. certificate)
Type of method:
flask method
Specific details on test material used for the study:
Designation in Test Facility: 17121903G
Date of Receipt: 20. Dec. 2017
Condition at Receipt: room temperature, in proper conditions

Name: CAB-O-SIL® high BET Untreated Fumed Silica
Batch no.: 4418650A-1
Other Designation: 17122001M
Appearance: white powder
Composition: 100% synthetic amorphous silica
CAS No.: 112945-52-5 (pyrogenic); 7631-86-9 (generic)
EINECS-No.: 231-545-4
Molecular formula: SiO2
Molecular weight: 60.074 g/mol
Homogeneity: homogeneous
Production date: 19. Sep. 2017
Expiry date: Shelflife is 24 months from production date
Storage: Room Temperature (20 ± 5°C); Keep away from humidity;
Keep away from volatile chemicals
Key result
Water solubility:
>= 225.8 - <= 239.4 mg/L
Conc. based on:
test mat.
Incubation duration:
> 1 - < 3 d
Temp.:
20 °C
pH:
>= 6 - <= 7
Remarks on result:
other: Main Test 1
Key result
Water solubility:
>= 216 - <= 237 mg/L
Conc. based on:
test mat.
Incubation duration:
>= 1 - <= 3 d
Temp.:
20 °C
pH:
4.08 - 4.18
Remarks on result:
other: Main Test 2
Details on results:
The determination of the solubility of the test item in water using two different methods (ICP-OES and photometry) showed similar results.
The solubility of the test item in the main test 1 was stated as:
232.6 ± 6.8 mg/L at 20.0 °C
= 232.6 ± 6.8 * 10-3 kg/m3 (SI units).
The solubility of the test item in the main test 2 was stated as:
226.5 ± 10.5 mg/L at 20.0 ± 0.5 °C
= 226.5 ± 10.5 * 10-3 kg/m3 (SI units).
The recovery rate of the test item in the main test 2 in comparison to the main test 1 was
97.4 %.

232.6 ± 6.8 mg/L at 20.0 °C

= 232.6 ± 6.8 * 10-3 kg/m3 (SI units).

226.5 ± 10.5 mg/L at 20.0 ± 0.5 °C

= 226.5 ± 10.5 * 10-3 kg/m3 (SI units).

Conclusions:
The determination of the solubility of the test item in water using two different methods (ICP-OES and photometry) showed similar results.
The solubility of the test item in the main test 1 was stated as:
232.6 ± 6.8 mg/L at 20.0 °C
= 232.6 ± 6.8 * 10-3 kg/m3 (SI units).
The solubility of the test item in the main test 2 was stated as:
226.5 ± 10.5 mg/L at 20.0 ± 0.5 °C
= 226.5 ± 10.5 * 10-3 kg/m3 (SI units).
The recovery rate of the test item in the main test 2 in comparison to the main test 1 was
97.4 %.
Executive summary:

The solubility of the test item CAB-O-SIL® high BET Untreated Fumed Silica in water was

determined by measurement of the Silicon concentration in the filtrated test solutions using

two different methods, ICP-OES and photometry. Potentially available undissolved particles

in the filtrated test item solutions were measured using Tyndall device. The concentration

of the test item was calculated from the silicon content of 46.75 % (100 % purity of the

test item).

The preliminary test which is described in the guideline was not performed as the solubility

of the test item was performed analogous to all silica samples. Therefore, the flask method

was used.

The main test was performed two times (in March and May 2018) for characterization purposes

(request by sponsor).

In both main tests, 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. Then, flasks 1A - 1C were taken from the shaker, tempered at

20.0 ± 0.5 °C, samples were taken, membrane filtrated and analysed for Silicon via ICPOES

on day 3 (flasks 1A, 1B, 1C). Due to a difference of less than 15 % in the concentrations

on days 2 and 3 and no upward tendency, both tests were finished on day 3. Therefore,

on the same day 3, 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.

All measurements using Tyndall device lay below LOD of the method (< 3 mg/L particle

concentration).

The solubility of the test item in the main test 1 was stated as:

232.6 ± 6.8 mg/L at 20.0 °C

= 232.6 ± 6.8 * 10-3 kg/m3 (SI units).

The solubility of the test item in the main test 2 was stated as:

226.5 ± 10.5 mg/L at 20.0 ± 0.5 °C

= 226.5 ± 10.5 * 10-3 kg/m3 (SI units).

The recovery rate of the test item in the main test 2 in comparison to the main test 1 was

97.4 %.

Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Jan. 28 - Feb. 8, 2019 (experimental phase)
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
Version / remarks:
1995
Deviations:
no
Qualifier:
according to
Guideline:
EU Method A.6 (Water Solubility)
Version / remarks:
2014
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of method:
flask method
Specific details on test material used for the study:
DAVISIL XWP1500A
Key result
Water solubility:
>= 82 - <= 90.4 mg/L
Loading of aqueous phase:
50 g/L
Incubation duration:
11 d
Temp.:
20 °C
pH:
>= 6 - <= 7.26
Details on results:
At the plateau, the concentration of the test item DAVISIL XWP1500A 90-130μ using ICP-OES was calculated based on the measured Silicon concentrations in flasks 1A-C (8 – 11 d) and 2 – 4 and the Silicon content in the test item was determined as 83.5 ± 1.0 mg/L.
Additionally, on day 11, the concentration of Silicon in the filtrated solutions (flasks 1C and flasks 2 – 4) was determined using photometry for comparison of the results with the first measurement via ICP-OES. The mean concentration of the test item DAVISIL XWP1500A 90-130μ in the four replicates was 90.9 ± 5.0 mg/L.
The determination of the solubility of the test item in water using two different methods (ICP-OES and photometry) showed similar results. The solubility of the test item was stated as 87.2 ± 5.2 mg/L at 20.0 ± 0.5 °C = 8.72 ± 0.52* 10^-2 kg/m3 (SI units) (mean value of two methods ± standard deviation of eight individual values (six vessels), nominal concentration 50 g/L).
Conclusions:
The determination of the solubility of the test item in water using two different methods (ICP-OES and photometry) showed similar results. The water solubility of the test item was stated as 87.2 ± 5.2 mg/L (mean value of two methods).
Executive summary:

The solubility of DAVISIL XWP1500A 90-130μ in water was determined by measurement of the Silicon concentrations in filtrated test solutions with the nominal concentration 50 g/L.

Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
26.09.2017-29.09.2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
Qualifier:
equivalent or similar to
Guideline:
EU Method A.6 (Water Solubility)
GLP compliance:
yes (incl. certificate)
Type of method:
flask method
Specific details on test material used for the study:
Designation in Test Facility: 17071805G
Date of Receipt: 18. Jul. 2017
Condition at Receipt: Room temperature, in proper conditions
Name: WACKER HDK® T30
Batch no.: VK78834
Appearance: white powder
Composition: pure silica
CAS No.: 112945-52-5
Molecular formula: SiO2
Purity: 99.8%
Homogeneity: homogeneous
Expiry date: at least end of 2018
Specific surface area: 290 m2/g
Storage: Room Temperature (20 ± 5°C), keep away from humidity
Key result
Water solubility:
>= 217.1 - <= 228.5 mg/L
Conc. based on:
test mat.
Incubation duration:
>= 1 - <= 3 d
Temp.:
20.5 °C
pH:
>= 3.58 - <= 6
Details on results:
The determination of the solubility of the test item in water using two different methods
(ICP-OES and photometry) showed very similar results. The solubility of the test item was
stated as 222.8 ± 5.7 mg/L at 20.5 °C

222.8 ± 5.7 mg/L at 20.5 °C

= 2.228 ± 0.057* 10-1 kg/m3 (SI units)

Conclusions:
The determination of the solubility of the test item in water using two different methods
(ICP-OES and photometry) showed very similar results. The water solubility of the test
item was stated as 222.8 ± 5.7mg/L (mean value of two methods).
Executive summary:

The solubility of the test item WACKER HDK® T30 in water was determined by measurement

of the Silicon concentration in the filtrated test solutions using two different methods,

ICP-OES and photometry. Potentially available undissolved particles in the filtrated test

item solutions were measured using Tyndall device.

The solubility of the test item was provided by the sponsor to be > 10 mg/L and therefore

the preliminary test described in the guideline was not performed. Following the guideline,

the flask method was used for the determination of the solubility of the test item in water.

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). Due to a difference of less than 15 % in the concentrations on

days 2 and 3 and no upward tendency in the three values, the test was finished on day 3.

Therefore, on the same day 3, 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.

All measurements using Tyndall device lay below LOD of the method (< 3 mg/L particle

concentration).

At the plateau, the concentration of the test item WACKER HDK® T30 using ICP-OES was

calculated based on the measured Silicon concentrations in flasks 1A-C and 2 – 4 and the

Silicon content in the test item as 220.2 ± 7.7 mg/L.

Additionally, on day 3, the concentration of Silicon in the filtrated solutions (flasks 1C and

flasks 2 – 4) was determined using photometry for comparison of the results with the first

measurement via ICP-OES. The mean concentration of the test item WACKER HDK® T30

in the four replicates was 225.4 ± 0.2 mg/L.

The determination of the solubility of the test item in water using two different methods

(ICP-OES and photometry) showed very similar results. The solubility of the test item was

stated as

222.8 ± 5.7 mg/L at 20.5 °C

= 2.228 ± 0.057* 10-1 kg/m3 (SI units)

(mean value of two methods ± standard deviation of eight individual values (six vessels),

nominal concentration 50 g/L)

Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
05.12.2014 - 23.03.2015
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
Qualifier:
equivalent or similar to
Guideline:
EU Method A.6 (Water Solubility)
GLP compliance:
yes (incl. certificate)
Type of method:
flask method
Specific details on test material used for the study:
Designation in Test Facility: 14111307G
Date of Receipt: 13. Nov. 2014
Condition at Receipt: room temperature, in proper conditions
Name: Perkasil SM 660
Batch no.: 1403257006
Appearance: white powder
Composition: 95-100% SiO2
CAS No.: 7631-86-9
EINECS-No.: 231-545-4
Molecular formula: SiO2
Molecular weight: 60.08 g/mol
Purity: ≥ 95%
Homogeneity: homogeneous
Vapour pressure: 0 hPa at 20 °C
Stability: stable
Solubility: slightly soluble >10 mg/L
Production date: Mar. 2014
Expiry date: Dec. 2018
Storage: not stated
BET surface area: 182 m2/g
Key result
Water solubility:
>= 102.5 - <= 113.7 mg/L
Conc. based on:
test mat.
Incubation duration:
> 1 - < 3 d
Temp.:
20 °C
pH:
>= 6 - <= 6.93
Details on results:
The determination of the solubility of the test item in water using two different methods (ICP-OES and photometry) showed similar results. The solubility of the test item was stated as
108.1 ± 5.6 mg/L at 20.0 ± 0.5 °C
(mean value of two methods ± standard deviation of eight individual values (six vessels), nominal concentration 50 g/L)

108.1 ± 5.6 mg/L at 20.0 ± 0.5 °C

= 1.081 ± 0.056 * 10-1 kg/m3 (SI units)

Conclusions:
The determination of the solubility of the test item in water using two different methods (ICP-OES and photometry) showed similar results. The solubility of the test item was stated as
108.1 ± 5.6 mg/L at 20.0 ± 0.5 °C
(mean value of two methods ± standard deviation of eight individual values (six vessels), nominal concentration 50 g/L)
Executive summary:

The solubility of the test item Perkasil SM 660 in water was determined by measurement

of the Silicon concentration in the filtrated test solutions using two different methods, ICPOES

and photometry. Potentially available undissolved particles in the filtrated test item

solutions were measured using Tyndall device.

The solubility of the test item was provided by the sponsor to be > 10 mg/L and therefore

the preliminary study described in the guideline was not performed. Following the guideline,

the flask method was used for the determination of the solubility of the test item in

water.

In the main study, after consultation with the sponsor, 50 g/L test item in water were used

for the test. Six individual flasks (flasks 1A - 1C and 2 – 4) were prepared. Four vessels

(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). Because of a difference of less than 15

% in the concentrations on days 2 and 3 and no upward tendency, the test was finished on

day 3. Therefore, on the same day 3, 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.

For the determination of the filtrated test solutions using Tyndall device three flasks 5 – 7

were prepared with the nominal concentration 50 g/L and the flasks were shaken for 72 ±

2 h. All measurements using Tyndall device lay below LOQ of the method (< 4 mg/L particle

concentration).

At the plateau, the concentration of the test item Perkasil SM 660 using ICP-OES was calculated

based on the measured Silicon concentrations in flasks 1A-C and 2 – 4 and the

Silicon content in the test item as 113.3 ± 0.5 mg/L.

Additionally, on day 3, the concentration of Silicon in the filtrated solutions (flasks 1C and

flasks 2 – 4) was determined using photometry for comparison of the results with the first

measurement via ICP-OES. The mean concentration of the test item Perkasil SM 660 in

the four replicates was 102.9 ± 1.2 mg/L.

Therefore, the determination of the solubility of the test item in water using two different

methods (ICP-OES and photometry) showed similar results. The solubility of the test item

was stated as

108.1 ± 5.6 mg/L at 20.0 ± 0.5 °C

= 1.081 ± 0.056 * 10-1 kg/m3 (SI units)

(mean value of two methods ± standard deviation of eight individual values (six vessels),

nominal concentration 50 g/L)

Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
19.01.2016-16.02.2016
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
Qualifier:
equivalent or similar to
Guideline:
EU Method A.6 (Water Solubility)
GLP compliance:
yes (incl. certificate)
Type of method:
flask method
Specific details on test material used for the study:
Designation in Test Facility: 15121713G, 15121714G, 15121715G, 15121716G, 15121717G
Date of Receipt: 17. Dec. 2015
Condition at Receipt: room temperature, in proper conditions
Name: SIPERNAT® 22 S ex WES, Germany
Batch nos.: 195111223 (15121713G), 195120323 (15121714G), 195120523 (15121715G), 195120623 (15121716G), 195120823 (15121717G)
Appearance: white powder
Composition: Silicon dioxide, chemically prepared
Purity: ≥ 97 % (foll. ISO 3262-19)
Homogeneity: homogeneous
Expiry date: 11. Nov. 2017 (15121713G), 02. Dec. 2017 (15121714G), 04. Dec. 2017 (15121715G), 05. Dec. 2017 (15121716G), 07. Dec. 2017 (15121717G)
Specific surface area: 187 m2/g (15121713G), 185 m2/g (15121714G), 184 m2/g (15121715G), 188 m2/g (15121716G), 190 m2/g (15121717G)
Storage: Room temperature: 20 ± 5 °C, keep away from humidity
CAS No.: 112926-00-8, 7631-86-9
Molecular formula: SiO2
Molecular weight: 60 g/mol
Key result
Water solubility:
>= 111 - <= 112.8 mg/L
Conc. based on:
test mat.
Incubation duration:
>= 1 - <= 3 d
Temp.:
20 °C
pH:
>= 5 - <= 6
Details on results:
The determination of the solubility of five batches of the test item in water using two different
methods (ICP-OES and photometry) showed very similar results for each batch. The total mean value of the solubility of the test items was
stated as111.9 ± 0.9 mg/L at 20.0 °C
Conclusions:
The determination of the solubility of five batches of the test item in water using two different methods (ICP-OES and photometry) showed very similar results for each batch. The total mean value of the solubility of the test items was stated as111.9 ± 0.9 mg/L at 20.0 °C
Executive summary:

The solubility of the test item SIPERNAT® 22 S ex WES, Germany (five batches) in water

was determined by measurement of the Silicon concentration in the filtrated test solutions

using two different methods, ICP-OES and photometry. The concentration of the test item

was calculated based on the measured Silicon concentrations and the Silicon content in

the test item (45.35 %). Potentially available undissolved particles in the filtrated test item

solutions were measured using Tyndall device.

The solubility of the test item was provided by the sponsor to be > 10 mg/L and therefore

the preliminary test described in the guideline was not performed. Following the guideline,

the flask method was used for the determination of the solubility of the test item in water.

In the main test, after consultation with the sponsor, 50 g/L test item in water were used for

the test. Six individual flasks (flasks 1A - 1C and 2 – 4) were prepared with the same nominal

load. For each batch the same procedure was performed. 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). Because of a difference of less than

15 % in the concentrations on days 2 and 3 and no upward tendency, the test was finished

on day 3. The final measurement was performed as determination from flasks 2 – 4 in the

same fashion.

Additionally, the test solutions from the flasks 1C and 2 – 4 were measured using photometry

on day 3. The solutions from the flasks 2 – 4 were examined for colloidal particles by

testing the solution using Tyndall device. All measurements using Tyndall device lay below

LOD of the method (< 3 mg/L particle concentration).

The determination of the solubility of five batches of the test item in water using two different

methods (ICP-OES and photometry) showed very similar results for each batch. The total mean value of the solubility of the test items was

stated as111.9 ± 0.9 mg/L at 20.0 °C

Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
26.11.2012 - 30.11.2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
Qualifier:
equivalent or similar to
Guideline:
EU Method A.6 (Water Solubility)
GLP compliance:
yes (incl. certificate)
Type of method:
flask method
Specific details on test material used for the study:
Designation in Test Facility: 12101103G
Date of Receipt: 11. Oct. 2012
Condition at Receipt: room temperature, in proper conditions
Name: Sylodent VP5
Batch no.: 1208257029
Appearance: white powder
Composition: SiO2 synthetic amorph
CAS No.: 7631-86-9
EINECS-No.: 231-545-4
Molecular formula: SiO2
Molecular weight: not stated
Purity: ≥ 95% SiO2
Homogeneity: homogeneous material
Solubility: H2O: 01-1 g/L; EtOH; acetone; CH3CN; DMSO: not stated
Production date: 08. Aug. 2012
Expiry date: 08. Aug. 2014
Storage: room temperature
Stability: H2O: 96 h; EtOH; acetone; CH3CN; DMSO: not stated
Key result
Water solubility:
>= 102.3 - <= 114.3 mg/L
Conc. based on:
test mat.
Incubation duration:
> 1 - < 3 d
Temp.:
20 °C
pH:
>= 6 - <= 6.58
Details on results:
The determination of the solubility of the test item in water using two different methods (AAS and photometry) showed identical results. Allmeasurements were used for calculation of water solubility of the test item. The solubility of the test item was stated as
108.3 ± 6.0 mg/L at 20.0 ± 0.3 °C
(mean value of two methods ± standard deviation of nine individual measurements (five vessels), nominal concentration 50 g/L)

108.3 ± 6.0 mg/L at 20.0 ± 0.3 °C

= 1.083 ± 0.060 * 10-1 kg/m3 (SI units)

Conclusions:
The determination of the solubility of the test item in water using two different methods (AAS and photometry) showed identical results. Allmeasurements were used for calculation of water solubility of the test item. The solubility of the test item was stated as
108.3 ± 6.0 mg/L at 20.0 ± 0.3 °C
(mean value of two methods ± standard deviation of nine individual measurements (five vessels), nominal concentration 50 g/L)
Executive summary:

The solubility of the test item Sylodent VP5 in water was determined by measuring of Silicium concentration in the filtrated test solutions using two different methods, AAS

and photometry.

The solubility of the test item was provided by the sponsor to be > 10 mg/L and therefore the preliminary study described in the guideline was not performed. According to the guideline, the flask method was used for the determination of the solubility of the test item in water.

In the main study, 50 g/L test item in water were used for the test. Six individual flasks (flasks 1A - 1C and 2 – 4) were prepared. Four vessels (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 and stored at 20.0 ± 0.5 °C. Samples were taken, membrane filtrated and analysed for Silicium via AAS. No difference above 15 % and no rising tendency in the Silicium concentration of the solutions were determined between sampling dates 2 and 3, indicating that the maximum concentration of the test item had been reached. Therefore, on the same day 3, flasks 2 – 4 were sampled and analysed for Silicium 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.

At the plateau, the concentration of the test item Sylodent VP5 was calculated based on the measured Silicium concentrations in flasks 1B-C and 2 – 4 and the Silicium

content in the test item as 104.1 ± 4.6 mg/L. Additionally, on day 3, the concentration of Silicium in the filtrated solutions (flasks 1C and flasks 2 – 4) was determined using photometry for comparison of the results with the first measurement via AAS. The mean concentration of the test item Sylodent VP5 in the four replicates was 113.5 ± 1.0 mg/L.

Therefore, the determination of the solubility of the test item in water using two different methods (AAS and photometry) showed identical results. The solubility of the test item was stated as

The determination of the solubility of the test item in water using two different methods (AAS and photometry) showed identical results. Allmeasurements were used for calculation of water solubility of the test item. The solubility of the test item was stated as

108.3 ± 6.0 mg/L at 20.0 ± 0.3 °C

= 1.083 ± 0.060 * 10-1kg/m3 (SI units)

(mean value of two methods ± standard deviation of nine individual measurements (five vessels), nominal concentration 50 g/L)

Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
24.11.2014 - 24.03.2015
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
Qualifier:
equivalent or similar to
Guideline:
EU Method A.6 (Water Solubility)
GLP compliance:
yes (incl. certificate)
Type of method:
flask method
Specific details on test material used for the study:
Designation in Test Facility: 14111305G
Date of Receipt: 13. Nov. 2014
Condition at Receipt: room temperature, in proper conditions
Name: Syloid 244 FP
Batch no.: 1000222580
Appearance: white powder
Composition: 95-100% SiO2
CAS No.: 7631-86-9
EINECS-No.: 231-545-4
Molecular formula: SiO2
Molecular weight: 60.08 g/mol
Purity: ≥ 95%
Homogeneity: homogeneous
Vapour pressure: 0 hPa at 20 °C
Stability: stable
Solubility: slightly soluble >10 mg/L
Production date: Mar. 2012
Expiry date: Dec. 2018
Storage: not stated
BET surface area: 349 m2/g
Key result
Water solubility:
>= 95.4 - <= 100.8 mg/L
Conc. based on:
test mat.
Incubation duration:
> 1 - < 4 d
Temp.:
20 °C
pH:
>= 1.16 - <= 7.62
Details on results:
The determination of the solubility of the test item in water using two different methods (ICP-OES and photometry) showed similar results. The solubility of the test item was stated as
98.1 ± 2.7 mg/L at 20.0 ± 0.5 °C
(mean value of two methods ± standard deviation of ten individual values (five vessels), nominal concentration 50 g/L)

98.1 ± 2.7 mg/L at 20.0 ± 0.5 °C

= 0.981 ± 0.027 * 10-1 kg/m3 (SI units)

Conclusions:
The determination of the solubility of the test item in water using two different methods (ICP-OES and photometry) showed similar results. The solubility of the test item was stated as
98.1 ± 2.7 mg/L at 20.0 ± 0.5 °C
(mean value of two methods ± standard deviation of ten individual values (five vessels), nominal concentration 50 g/L)
Executive summary:

The solubility of the test item Syloid 244 FP in water was determined by measurement of

the Silicon concentration in the filtrated test solutions using two different methods, ICPOES

and photometry. Potentially available undissolved particles in the filtrated test item

solutions were measured using Tyndall device.

The solubility of the test item was provided by the sponsor to be > 10 mg/L and therefore

the preliminary study described in the guideline was not performed. Following the guideline,

the flask method was used for the determination of the solubility of the test item in

water.

In the main study, 50 g/L test item in water were used for the test. Six individual flasks

(flasks 1A - 1C and 2 – 4) were prepared. Four vessels (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). Due to the upward tendency in the flasks 1A – C, the flask 1C was

additionally measured on the following day 4. Because of a difference of less than 15 % in

the concentrations on days 3 and 4 and no upward tendency, the test was finished on day

4. Therefore, on the same day 4, 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.

For the determination of the filtrated test solutions using Tyndall device three flasks 5 – 7

were prepared with the nominal concentration 50 g/L and the flasks were shaken for 96 ±

2 h. All measurements using Tyndall device lay below LOQ of the method (< 4 mg/L particle

concentration).

At the plateau, the concentration of the test item Syloid 244 FP using ICP-OES was calculated

based on the measured Silicon concentrations in flasks 1B-C and 2 – 4 and the Silicon

content in the test item as 96.4 ± 1.0 mg/L. The measurement from the flask 1A was

not used in the calculation of the mean, as equilibration was not reached on day 1.

Additionally, on day 4, the concentration of Silicon in the filtrated solutions (flasks 1C and

flasks 2 – 4) was determined using photometry for comparison of the results with the first

measurement via ICP-OES. The mean concentration of the test item Syloid 244 FP in the

four replicates was 100.6 ± 2.4 mg/L.

Therefore, the determination of the solubility of the test item in water using two different

methods (ICP-OES and photometry) showed similar results. The solubility of the test item

was stated as

98.1 ± 2.7 mg/L at 20.0 ± 0.5 °C

= 0.981 ± 0.027 * 10-1 kg/m3 (SI units)

(mean value of two methods ± standard deviation of ten individual values (five vessels),

nominal concentration 50 g/L)

Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
05.12.2014 - 20.03.2015
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
Qualifier:
equivalent or similar to
Guideline:
EU Method A.6 (Water Solubility)
GLP compliance:
yes (incl. certificate)
Type of method:
flask method
Specific details on test material used for the study:
Designation in Test Facility: 14111306G
Date of Receipt: 13. Nov. 2014
Condition at Receipt: room temperature, in proper conditions
Name: Syloid 74 C
Batch no.: 1000240283
Appearance: white powder
Composition: 95-100% SiO2
CAS No.: 7631-86-9
EINECS-No.: 231-545-4
Molecular formula: SiO2
Molecular weight: 60.08 g/mol
Purity: ≥ 95%
Homogeneity: homogeneous
Vapour pressure: 0 hPa at 20 °C
Stability: stable
Solubility: slightly soluble >10 mg/L
Production date: Mar. 2013
Expiry date: Dec. 2018
Storage: not stated
BET surface area: 377 m2/g
Key result
Water solubility:
>= 102.4 - <= 109.6 mg/L
Conc. based on:
test mat.
Incubation duration:
> 1 - < 3 d
Temp.:
20 °C
pH:
>= 6 - <= 6.97
Details on results:
The determination of the solubility of the test item in water using two different methods (ICP-OES and photometry) showed similar results. The solubility of the test item was stated as
106.0 ± 3.6 mg/L at 20.0 ± 0.5 °C
(mean value of two methods ± standard deviation of eight individual values (five vessels), nominal concentration 50 g/L)

106.0 ± 3.6 mg/L at 20.0 ± 0.5 °C

= 1.06 ± 0.036 * 10-1 kg/m3 (SI units)

Conclusions:
The determination of the solubility of the test item in water using two different methods (ICP-OES and photometry) showed similar results. The solubility of the test item was stated as
106.0 ± 3.6 mg/L at 20.0 ± 0.5 °C
(mean value of two methods ± standard deviation of eight individual values (five vessels), nominal concentration 50 g/L)
Executive summary:

The solubility of the test item Syloid 74 C in water was determined by measurement of the Silicon concentration in the filtrated test solutions using two different methods, ICP-OES and photometry. Potentially available undissolved particles in the filtrated test item solutions were measured using Tyndall device.

The solubility of the test item was provided by the sponsor to be > 10 mg/L and therefore the preliminary study described in the guideline was not performed. Following the guideline, the flask method was used for the determination of the solubility of the test item in water.

In the main study, after consultation with the sponsor, 50 g/L test item in water were used for the test. Six individual flasks (flasks 1A - 1C and 2 – 4) were prepared. Four vessels (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). Because of a difference of less than 15 % in the concentrations on days 2 and 3 and no upward tendency, the test was finished on day 3. Therefore, on the same day 3, 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.

For the determination of the filtrated test solutions using Tyndall device three flasks 5 – 7 were prepared with the nominal concentration 50 g/L and the flasks were shaken for 72 ± 2 h. All measurements using Tyndall device lay below LOQ of the method (< 4 mg/L particle concentration).

At the plateau, the concentration of the test item Syloid 74 C using ICP-OES was calculated based on the measured Silicon concentrations in flasks 1B-C and 2 – 4 and the Silicon content in the test item as 103.0 ± 0.5 mg/L. The measurement from the flask 1A was stated as outlier and was not used in the calculation of the mean. Additionally, on day 3, the concentration of Silicon in the filtrated solutions (flasks 1C and flasks 2 – 4) was determined using photometry for comparison of the results with the first measurement via ICP-OES. The mean concentration of the test item Syloid 74 C in the four replicates was 109.0 ± 2.6 mg/L.

Therefore, the determination of the solubility of the test item in water using two different methods (ICP-OES and photometry) showed similar results. The solubility of the test item was stated as 106.0 ± 3.6 mg/L at 20.0 ± 0.5 °C = 1.06 ± 0.036 * 10-1 kg/m3 (SI units)

(mean value of two methods ± standard deviation of eight individual values (five vessels), nominal concentration 50 g/L)

Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
24.11.2014 - 19.03.2015
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
Qualifier:
equivalent or similar to
Guideline:
EU Method A.6 (Water Solubility)
GLP compliance:
yes (incl. certificate)
Type of method:
flask method
Specific details on test material used for the study:
Designation in Test Facility: 14111304G
Date of Receipt: 13. Nov. 2014
Condition at Receipt: room temperature, in proper conditions
Name: Syloid Al - 1 FP
Batch no.: 1000265654
Appearance: white powder
Composition: 95-100% SiO2
CAS No.: 7631-86-9
EINECS-No.: 231-545-4
Molecular formula: SiO2
Molecular weight: 60.08 g/mol
Purity: ≥ 95%
Homogeneity: homogeneous
Vapour pressure: 0 hPa at 20 °C
Stability: stable
Solubility: slightly soluble >10 mg/L
Production date: Sep. 2014
Expiry date: Dec. 2018
Storage: not stated
BET surface area: 781 m2/g
Key result
Water solubility:
>= 139.5 - <= 146.3 mg/L
Conc. based on:
test mat.
Incubation duration:
> 1 - < 3 d
Temp.:
20 °C
pH:
>= 5.73 - <= 6
Details on results:
The determination of the solubility of the test item in water using two different
methods (ICP-OES and photometry) showed similar results. The solubility of the test item
was stated as
142.9 ± 3.4 mg/L at 20.0 ± 0.5 °C
(mean value of two methods ± standard deviation of nine individual values (five vessels),
nominal concentration 50 g/L)

142.9 ± 3.4 mg/L at 20.0 ± 0.5 °C

= 1.429 ± 0.034 * 10-1 kg/m3 (SI units)

Conclusions:
The determination of the solubility of the test item in water using two different
methods (ICP-OES and photometry) showed similar results. The solubility of the test item
was stated as
142.9 ± 3.4 mg/L at 20.0 ± 0.5 °C
(mean value of two methods ± standard deviation of nine individual values (five vessels),
nominal concentration 50 g/L)
Executive summary:

The solubility of the test item Syloid Al - 1 FP in water was determined by measurement of

the Silicon concentration in the filtrated test solutions using two different methods, ICPOES

and photometry. Potentially available undissolved particles in the filtrated test item

solutions were measured using Tyndall device.

The solubility of the test item was provided by the sponsor to be > 10 mg/L and therefore

the preliminary study described in the guideline was not performed. Following the guideline,

the flask method was used for the determination of the solubility of the test item in

water.

In the main study, 50 g/L test item in water were used for the test. Six individual flasks

(flasks 1A - 1C and 2 – 4) were prepared. Four vessels (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). Because of a difference of less than 15 % in the concentrations on

days 2 and 3 and no upward tendency, the test was finished on day 3. Therefore, on the

same day 3, 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.

For the determination of the filtrated test solutions using Tyndall device three flasks 5 – 7

were prepared with the nominal concentration 50 g/L and the flasks were shaken for 72 ±

2 h. All measurements using Tyndall device lay below LOQ of the method (< 4 mg/L particle

concentration).

At the plateau, the concentration of the test item Syloid Al - 1 FP using ICP-OES was calculated

based on the measured Silicon concentrations in flasks 1B-C and 2 – 4 and the

Silicon content in the test item as 140.2 ± 1.6 mg/L. The measurement from the flask 1A

was stated as outlier (Grubbs outlier test).

Additionally, on day 3, the concentration of Silicon in the filtrated solutions (flasks 1C and

flasks 2 – 4) was determined using photometry for comparison of the results with the first

measurement via ICP-OES. The mean concentration of the test item Syloid Al - 1 FP in the

four replicates was 146.2 ± 0.8 mg/L.

Therefore, the determination of the solubility of the test item in water using two different

methods (ICP-OES and photometry) showed similar results. The solubility of the test item

was stated as

142.9 ± 3.4 mg/L at 20.0 ± 0.5 °C

= 1.429 ± 0.034 * 10-1 kg/m3 (SI units)

(mean value of two methods ± standard deviation of nine individual values (five vessels),

nominal concentration 50 g/L)

Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
24.11.2014 - 18.03.2015
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
Qualifier:
equivalent or similar to
Guideline:
EU Method A.6 (Water Solubility)
GLP compliance:
yes (incl. certificate)
Type of method:
flask method
Specific details on test material used for the study:
Designation in Test Facility: 14111303G
Date of Receipt: 13. Nov. 2014
Condition at Receipt: room temperature, in proper conditions
Name: Syloid MX 107
Batch no.: 1405280021
Appearance: white powder
Composition: 95-100% SiO2
CAS No.: 7631-86-9
EINECS-No.: 231-545-4
Molecular formula: SiO2
Molecular weight: 60.08 g/mol
Purity: ≥ 95%
Homogeneity: homogeneous
Vapour pressure: 0 hPa at 20 °C
Stability: stable
Solubility: slightly soluble >10 mg/L
Production date: May 2014
Expiry date: Dec. 2018
BET surface area: 749 m2/g
Key result
Water solubility:
>= 131 - <= 139.9 mg/L
Conc. based on:
test mat.
Incubation duration:
> 1 - < 3 d
Temp.:
20 °C
pH:
>= 6 - <= 6.71
Details on results:
The determination of the solubility of the test item in water using two different methods (ICP-OES and photometry) showed similar results. The solubility of the test item was stated as
135.4 ± 4.4 mg/L at 20.0 ± 0.5 °C
(mean value of two methods ± standard deviation of ten individual values (six vessels), nominal concentration 50 g/L)

135.4 ± 4.4 mg/L at 20.0 ± 0.5 °C

= 1.354 ± 0.044 * 10-1 kg/m3 (SI units)

Conclusions:
The determination of the solubility of the test item in water using two different methods (ICP-OES and photometry) showed similar results. The solubility of the test item was stated as
135.4 ± 4.4 mg/L at 20.0 ± 0.5 °C
(mean value of two methods ± standard deviation of ten individual values (six vessels), nominal concentration 50 g/L)
Executive summary:

The solubility of the test item Syloid MX 107 in water was determined by measurement of

the Silicon concentration in the filtrated test solutions using two different methods, ICPOES

and photometry. Potentially available undissolved particles in the filtrated test item

solutions were measured using Tyndall device.

The solubility of the test item was provided by the sponsor to be > 10 mg/L and therefore,

the preliminary study described in the guideline was not performed. Following the guideline,

the flask method was used for the determination of the solubility of the test item in

water.

In the main study, after consultation with the sponsor, 50 g/L test item in water were used

for the test. Six individual flasks (flasks 1A - 1C and 2 – 4) were prepared. Four vessels

(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). Because of a difference of less than

15 % in the concentrations on days 2 and 3 and no upward tendency, the test was finished

on day 3. Therefore, on the same day 3, 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.

For the determination of the filtrated test solutions using Tyndall device three flasks 5 – 7

were prepared with the nominal concentration 50 g/L and the flasks were shaken for 72 ±

2 h. All measurements using Tyndall device lay below LOQ of the method (< 4 mg/L particle

concentration).

At the plateau, the concentration of the test item Syloid MX 107 using ICP-OES was calculated

based on the measured Silicon concentrations in flasks 1A-C and 2 – 4 and the Silicon

content in the test item as 133.0 ± 2.5 mg/L.

Additionally, on day 3, the concentration of Silicon in the filtrated solutions (flasks 1C and

flasks 2 – 4) was determined using photometry for comparison of the results with the first

measurement via ICP-OES. The mean concentration of the test item Syloid MX 107 in the

four replicates was 138.9 ± 4.4 mg/L.

Therefore, the determination of the solubility of the test item in water using two different

methods (ICP-OES and photometry) showed similar results. The solubility of the test item

was stated as

135.4 ± 4.4 mg/L at 20.0 ± 0.5 °C

= 1.354 ± 0.044 * 10-1 kg/m3 (SI units)

(mean value of two methods ± standard deviation of ten individual values (six vessels),

nominal concentration 50 g/L)

Description of key information

Water solubility of all non surface-treated SAS products (silica gel, colloidal, precipitated and pyrogenic SAS) is in the range of 100 mg/L or higher.

Applying a modified method to accomplish sufficient material wetting, all hydrophobic SAS products analyzed (surface treated pyrogenic SAS only) exhibit a solubility between 100 and 160 mg/L in 10 % ethanol/water. It is expected, that other SAS products not tested so far will fit into that range. Thus, we conclude that the solubility of hydrophobic SAS (surface-treated SAS) products does not differ from the results of hydrophilic SAS (non-surface-treated SAS).  

Key value for chemical safety assessment

Additional information

See also in IUCLID section 13 attached "Expert statement on Water solubility"