Silicic acid, sodium salt

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study, but no information on purity of test substance.

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

conforms with OECD 202, part 1

GLP compliance:

yes

Remarks:

Henkel KGaA, Forschung Biologie/ Produktsicherheit Oekologie.

Analytical monitoring:

not specified

Vehicle:

yes

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Source: BioInternational B.V. NJ Hoorn,The Netherlands
- Age at study initiation (mean and range, SD): not reported (neonates)
- Method of breeding: incubation of ephipids at 4800 Lux and 19-22°C. The ephipids are grown on M4-Medium according to Elendt. Neonates are incubated at 900 Lux (16h light-8h dark cycle), 20°C and grown on M4-Medium according to Elendt


ACCLIMATION
- Acclimation conditions (same as test or not): yes
- Type and amount of food: green algae Spirula
- Feeding frequency: feeding terminated 3 hrs before start of the test

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20.3-20.5°C

pH:

7.8-8.0 (adjusted) and 9-11 (not adjusted)

Nominal and measured concentrations:

nominal: 100, 300, 1000, 3000, 10000 mg a.s./L

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

100 mg/L

Remarks on result:

other: pH 7.8-8

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

1 700 mg/L

Remarks on result:

other: pH 7.8-8

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

10 000 mg/L

Remarks on result:

other: pH 7.8-8

Results with reference substance (positive control):

Concentrations: not reported - Results: EC50 (24 hr) 0.9-1.9 mg/L for potassium dichromate.

Effect data (Immobilisation): EC0: 1000 mg/L, EC50: 1700 mg/L and EC100: 3000 mg/L (pH 9-11) EC0: 100 mg/L, EC50: 1700 mg/L and EC100: 10000 mg/L (pH 7.8-8) - Concentration / response curve: not reported - Cumulative immobilisation: not reported - Effect concentration vs. test substance solubility: not reported - Other effects: Not reported RESULTS CONTROL: not reported.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Adequacy of study:

other information

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Documentation insufficient for complete assessment.

Principles of method if other than guideline:

Method: other: according to Anderson et al (1948)

GLP compliance:

no

Analytical monitoring:

not specified

Test organisms (species):

Daphnia magna

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

216 - 247 mg/L

RS-Freetext:
RESULTS: EXPOSED
- Nominal/measured concentrations: Not reported.
- Effect data (Immobilisation): LC50 (24 h): 575 mg/l; LC50
(48 h): 494 mg/l; LC50 (72 h): 413 mg/l; LC50 (96 h) 216
mg/l (in glass-wool filtered University Lake Water), and 247
mg/l by exposure in standard reference water (SRW).
No other details reported.
RESULTS CONTROL: Not reported.
RESULTS: TEST WITH REFERENCE SUBSTANCE
No details reported.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Documentation insufficient for complete assessment.

Principles of method if other than guideline:

Method: acute toxicity test; no further information

GLP compliance:

no

Analytical monitoring:

not specified

Test organisms (species):

Daphnia magna

Duration:

100 h

Dose descriptor:

EC50

Effect conc.:

247 mg/L

RS-Freetext:
RESULTS: EXPOSED
- Nominal/measured concentrations: not reported
- Effect data (Immobilisation): EC50 247 ppm
- Concentration / response curve: not reported
- Cumulative immobilisation: not reported
- Effect concentration vs. test substance solubility: not
reported 
- Other effects: not reported 
RESULTS CONTROL: not reported
RESULTS: TEST WITH REFERENCE SUBSTANCE
- Concentrations: not reported
- Results: not reported

Reference 4

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Documentation insufficient for assessment.

Principles of method if other than guideline:

Method: other: according to Anderson et al (1948)

GLP compliance:

no

Analytical monitoring:

not specified

Test organisms (species):

other aquatic crustacea: probably Hyallela sp. (Amphipoda)

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

160 mg/L

RS-Freetext:
RESULTS: EXPOSED
- Nominal/measured concentrations: Not reported.
- Effect data (Immobilisation): LC50 (24 h): 895 mg/l; LC50
(48 h): 263 mg/l; LC50 (72 h): 261 mg/l; LC50 (96 h): 160
mg/l
No other details reported.
RESULTS CONTROL: Not reported.
RESULTS: TEST WITH REFERENCE SUBSTANCE
No details reported.

Reference 5

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Documentation insufficient for assessment.

Principles of method if other than guideline:

Method: other: according to Anderson et al. (1948)

GLP compliance:

no

Analytical monitoring:

not specified

Test organisms (species):

other: Lymnaea sp. eggs

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

632 mg/L

RS-Freetext:
RESULTS: EXPOSED
- Nominal/measured concentrations: Not reported.
- Effect data (mortality): LC50 (24 h): 632 mg/l; LC50 (48
h): 630 mg/l; LC50 (72 h): 630 mg/l; LC50 (96 h): 632 mg/l
No other details reported.
RESULTS CONTROL: Not reported.
RESULTS: TEST WITH REFERENCE SUBSTANCE
No details reported.

Description of key information

EC50 (48 h): 1700 mg/L (Daphnia magna)
However, for the purpose of risk assessment and as explained in the section on the calculation of Predicted No Effect Concentrations, the PNEC is derived from the ubiquitous SiO2 background concentration in freshwater in Europe, which is 7.5 mg/L.

Additional information

In a GLP study by Kirch (1997) following EU Guideline 92/69/EWG, which corresponds to OECD guideline 202, part 1, exposure of the freshwater cladoceran Daphnia magna to sodium silicate solutions (MR 3.2, 35 wt %) at pH 9 - 11 and a pH adjusted to 7.8 - 8.0 resulted in a 48 h EC50 of 1700 mg active matter/L in both cases.