Silver docosanoate

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

transformation / dissolution of metals and inorganic metal compounds

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

16/09/2012 - 18/09/2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: ASTM D5517-07 standard test method for determining the extractability of metals from art materials (ASTM, 2007)

Qualifier:

according to guideline

Guideline:

other: SOP for the bio-accessibility testing programme of Eurometaux

Deviations:

no

Remarks:

: SOP based on ASTM D5517-07: standard test method for determining the extractability of metals from art materials (2007) and the Standard Operating Procedure for the bio-accessibility testing Programme (Eurometaux, 2010)

GLP compliance:

yes

Remarks:

ISO 17025 laboratory

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

564 µg/L

Element analysed:

Ag

Loading of aqueous phase:

2 000 mg/L

Incubation duration:

168 h

Test conditions:

pH 7.4
T = 37°C

Details on results:

Significant amounts of silver were measured: An average dissolved silver concentration of 353 ± 13 μg/L Ag was measured after 2 hours of exposure to the simulated gastric fluid (pH 1.5) with a between-vessel variation of 4%. Based on the specific surface area of Silver behenate SI (15m2/g test item) a release per surface of 0.117 mg/m2 was calculated. Based on the molecular formula of the test item and the measured silver concentrations, a silver release of approximately 0.73% could be calculated at the 2 hours endpoint.
The test item was very dusty and electrostatic. Most of the test item remained mainly float and crept up along the walls of the Erlenmeyer’s.

An average dissolved silver concentration of 403 ± 9 μg/L Ag wa smeasured after 24 hours of exposure to the simulated interstitial fluid (pH 7.4) with a between-vessel variation of 2%. Based on the specific surface area of Silver behenate SI (15m2/g test item) a release per surface of 0.013 mg/m2 was calculated. Based on the molecular formula of the test item and the measured silver concentrations, a silver release of approximately 0.08% could be calculated at the 24 hours sampling point.

An average dissolved silver concentration of 564 ± 12 μg/L Ag was measured after 168 hours of exposure to the simulated interstitial fluid (pH 7.4) with a between-vessel variation of 2%. Here, a release per surface of 0.019 mg/m2 was calculated. Based on the molecular formula of the test item and the measured silver concentrations, a silver release of approximately 0.12% could be calculated at the 168 hours endpoint.

Conclusions:

Interpretation of results: slightly soluble (0.1-100 mg/L)
During this study on Silver behenate SI at a loading of 2 g/L in simulated interstitial fluid (pH 7.4), it was shown that significant amounts of silver were measured. An average value of 403 μg/L Ag (CV = 2%) was found after 24 hours of extraction, corresponding with a silver release per surface of 0.013 mg/m2. After 168 hours of extraction, an average value of 564 μg/L Ag (CV = 4%) was measured corresponding with a silver release per surface of 0.019 mg/m2.
The results can be assumed reliable since the test conditions stayed constant during the experiment.

Reference 2

Endpoint:

transformation / dissolution of metals and inorganic metal compounds

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

16/09/2012 - 18/09/2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: ASTM D5517-07 standard test method for determining the extractability of metals from art materials (ASTM, 2007)

Qualifier:

according to guideline

Guideline:

other: SOP for the bio-accessibility testing programme of Eurometaux

Deviations:

no

Remarks:

: SOP based on ASTM D5517-07: standard test method for determining the extractability of metals from art materials (2007) and the Standard Operating Procedure for the bio-accessibility testing Programme (Eurometaux, 2010)

GLP compliance:

yes

Remarks:

ISO 17025 laboratory

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

258 µg/L

Element analysed:

Ag

Loading of aqueous phase:

2 000 mg/L

Incubation duration:

168 h

Test conditions:

pH 4.74
T = 37°C

Details on results:

Significant amounts of silver were measured: An average dissolved silver concentration of
353 ± 13 μg/L Ag was measured after 2 hours of exposure to the simulated gastric fluid (pH 1.5) with a between-vessel variation of 4%. Based on the specific surface area of Silver behenate SI (15m2/g test item) a release per surface of 0.117 mg/m2 was calculated. Based on the molecular formula of the test item and the measured silver concentrations, a silver release of approximately 0.73% could be calculated at the 2 hours endpoint.
The test item was very dusty and electrostatic. Most of the test item remained mainly float and crept up along the walls of the Erlenmeyer’s.

Significant amounts of silver were measured:

1. An average dissolved silver concentration of 234 ± 9μg/L Ag was measured after 24 hours of exposure to the simulated intracellular fluid (pH 4.5-5.0) with a between-vessel variation of 4%. Based on the specific surface area of Silver behenate SI (15m2/g test item) a release per surface of 0.008 mg/m2 was found. Based on the molecular formula of the test item and the measured silver concentrations, a silver release of approximately 0.049% could be calculated at the 24 hours sampling point.

2. An average dissolved silver concentration of 258 ± 1μg/L Ag was measured after 168 hours of exposure to the simulated intracellular fluid (pH 4.5-5.0) with a between-vessel variation of 0%. Here, a silver release per surface of 0.009 mg/m2 was found. Based on the molecular formula of the test item and the measured silver concentrations, a silver release of approximately 0.054% could be calculated at the 168 hours endpoint.

Conclusions:

Interpretation of results: slightly soluble (0.1-100 mg/L)
During this study on Silver behenate SI at a loading of 2 g/L in simulated intracellular fluid (pH 4.5-5.0), it was shown that significant amounts of silver were measured. An average value of 234 μg/L Ag (CV = 4%) was found after 24 hours of extraction, corresponding with a silver release per surface of 0.008 mg/m2. After 168 hours of extraction, an average value of 258 μg/L Ag (CV = 0%) was measured corresponding with a silver release per surface of 0.009 mg/m2.
The results can be assumed reliable since the test conditions stayed constant during the experiment.

Reference 3

Endpoint:

transformation / dissolution of metals and inorganic metal compounds

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

18/10/2012 - 2/11/2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: ASTM D5517-07 standard test method for determining the extractability of metals from art materials (ASTM, 2007)

Qualifier:

according to guideline

Guideline:

other: SOP for the bio-accessibility testing programme of Eurometaux

Deviations:

no

Remarks:

: SOP based on ASTM D5517-07: standard test method for determining the extractability of metals from art materials (2007) and the Standard Operating Procedure for the bio-accessibility testing Programme (Eurometaux, 2010)

GLP compliance:

yes

Remarks:

ISO 17025 laboratory

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

331 µg/L

Element analysed:

Ag

Loading of aqueous phase:

2 000 mg/L

Incubation duration:

168 h

Test conditions:

pH 6.51
T = 30°C

Details on results:

The temperature of the sampled test solutions fluctuated between 29.9°C and 30.1°C which was in line with the test conditions of 30 ± 1°C.
The pH measured in the additional test item vessel at the start of the test was 6.51 i.e. within the specifications of pH 6.5 ± 0.1, therefore pH adjustment of the test vessels was not needed. At the end of the test the pH in the blank control vessel and the test vessels was between 6.50 and 6.52.
The blank control vessels showed no significant concentrations of silver above the reporting limit of 10 μg/L Ag

Significant amounts of silver were measured:

1. An average dissolved silver concentrationof 343 ± 10 μg/L Ag was measured after 24hours of exposure to the simulated perspiration fluid (pH 6.5) with a between-vessel variation of 3%. Based on the specific surface area of Silver behenate SI (15m2/g test item) a release per surface of 0.011 mg/m2 was calculated. Based on the molecular formula of the test item and the measured silver concentrations, a silver release of approximately 0.071% could be calculated at the 24 hours sampling point.

2. An average dissolved silver concentration of 331 ± 1μg/L Ag was measured after 168hours of exposure to the simulated perspiration fluid (pH 6.5) with a between-vessel variation of 0%. Here, a silver release per surface of 0.011 mg/m2 was calculated. Based on the molecular formula of the test item and the measured silver concentrations, a silver release of approximately 0.069% could be calculated at the 168 hours endpoint.

Conclusions:

Interpretation of results: slightly soluble (0.1-100 mg/L)
During this study on Silver behenate SI at a loading of 2 g/L in simulated perspiration fluid (pH 6.5), it was shown that significant amounts of silver were measured. An average value of 343 μg/L Ag (CV = 3%) was found after 24 hours of extraction, corresponding with a silver release per surface of 0.011 mg/m2. After 168 hours of extraction, an average value of 331 μg/L Ag (CV = 0%) was measured corresponding with a silver release per surface of 0.011 mg/m2.
The results can be assumed reliable since the test conditions stayed constant during the experiment.

Reference 4

Endpoint:

transformation / dissolution of metals and inorganic metal compounds

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

16/09/2012 - 18/09/2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: SOP for the bio-accessibility testing programme of Eurometaux

Deviations:

no

Remarks:

: SOP based on ASTM D5517-07: standard test method for determining the extractability of metals from art materials (2007) and the Standard Operating Procedure for the bio-accessibility testing Programme (Eurometaux, 2010)

Qualifier:

according to guideline

Guideline:

other: ASTM D5517-07 standard test method for determining the extractability of metals from art materials (ASTM, 2007)

GLP compliance:

yes

Remarks:

ISO 17025 laboratory

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

353 µg/L

Element analysed:

Ag

Loading of aqueous phase:

200 mg/L

Incubation duration:

2 h

Test conditions:

pH 1.5
T = 37°C

Details on results:

Significant amounts of silver were measured: An average dissolved silver concentration of
353 ± 13 μg/L Ag was measured after 2 hours of exposure to the simulated gastric fluid (pH 1.5) with a between-vessel variation of 4%. Based on the specific surface area of Silver behenate SI (15m2/g test item) a release per surface of 0.117 mg/m2 was calculated. Based on the molecular formula of the test item and the measured silver concentrations, a silver release of approximately 0.73% could be calculated at the 2 hours endpoint.
The test item was very dusty and electrostatic. Most of the test item remained mainly float and crept up along the walls of the Erlenmeyer’s.

In the blank corrected test item vessels with a loading of 0.2 g/L Silver behenate SI, the following average dissolved silver concentration of 353 μg/L Ag (CV = 4%) was measured after 2 hours of exposure to the simulated gastric fluid (pH 1.5). Based on the specific surface area of Silver behenate SI (15 m2/g), this corresponds with a silver release per surface of 0.117 mg/m2. Based on the molecular formula of the test item and the measured silver concentrations, a silver release of approximately 0.73% could be calculated at the 2 hours endpoint.

Conclusions:

Interpretation of results: slightly soluble (0.1-100 mg/L)
During this study on Silver behenate SI at a loading of 0.2 g/L in simulated gastric fluid (pH 1.5), it was shown that significant amounts of silver were measured. For silver an average value of 353 μg/L Ag (CV = 4%) was found after 2 hours of extraction, corresponding with a silver release per surface of 0.117 mg/m2.
The results can be assumed reliable since the test conditions stayed constant during the experiment.

Reference 5

Endpoint:

transformation / dissolution of metals and inorganic metal compounds

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Guideline study but not GLP

Qualifier:

according to guideline

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

Deviations:

no

GLP compliance:

no

Remarks:

There is no significant deviation from the OECD principles of GLP that adversely affected the integrity of the study

Type of method:

other: Dissociaton/dissolution study, ICP-MS

Type of test:

screening transformation/dissolution test - sparingly soluble metal compounds

Mean dissolved conc.:

73.8 µg/L

Element analysed:

Ag

Loading of aqueous phase:

100 mg/L

Incubation duration:

24 h

Test conditions:

pH 6

Type of test:

screening transformation/dissolution test - sparingly soluble metal compounds

Mean dissolved conc.:

26 µg/L

Element analysed:

Ag

Loading of aqueous phase:

100 mg/L

Incubation duration:

24 h

Test conditions:

pH 8

Details on results:

The test can be assumed reliable because the test conditions stayed constant during the experiment and may be important in the design of a full test for classification purposes.

Conclusions:

The test substance Ag behenate is insoluble (< 0.1 mg/L)i.e. Ag concentrations of 74 and 26 µg/L at pH 6 and 8, respectively.

Description of key information

Transformation dissolution (OECD Test Guideline No 29) and bio-elution tests demonstrate the substance is slightly soluble (< 0.1 mg/L). When dissolved, the substance dissociates between Ag and behenate to levels above the ecotoxicity reference value.

Key value for chemical safety assessment

Water solubility:

0.1 mg/L

at the temperature of:

20 °C