Silicic acid, aluminum sodium salt

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-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:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Version / remarks:

The temperature was not within the range stated in the guideline (17.4-21.3 °C instead of 18.0-22.0 °C). As no immobility in the blank control occurred during the test and all validity criteria were fulfilled, this deviation was stated as uncritical.

Qualifier:

according to guideline

Guideline:

EU Method C.20 (Daphnia magna Reproduction Test)

GLP compliance:

yes (incl. QA statement)

Remarks:

(Landesamt für Umwelt-, Wasserwirtschaft und Gewerbeaufsicht, Rheinland-Pfalz)

Specific details on test material used for the study:

Name: Silicic acid Aluminium Magnesium Sodium Salt
Batch no. code #: 1107274003
Appearance: white powder
Composition: Silicic acid Aluminium Magnesium Sodium Salt
CAS No.: 12040-43-6
EINECS-No.: 234-919-5
Molecular formula: not stated
Molecular weight: unknown
Purity: > 99 %
Homogeneity: homogeneous
Volatility: not volatile
Stability: stable at room temperature
Solubility: poorly soluble in water
Production date: 2011
Expiry date: 01.11.2018
Storage room temperature: 20 ± 5 °C, dry

Analytical monitoring:

yes

Details on sampling:

Selection of Daphnia
23 hours before the start of the test, the adult animals were separated from the young. 1 hour before the start of the test, the adults were caught with the help of a glass tube, and the newborn daphnia, aged between 0 and 22 hours, were sieved from the medium and immediately placed into a 250 mL beaker containing dilution water. After a settling-in period of 30 minutes, animals which showed no apparent damage were used for the test.

Vehicle:

no

Details on test solutions:

Deionised water with an enrichment of certain minerals was used in the test. The minerals which are added comply with the composition M4, (full composition see Annex 4, page 25: Composition of Dilution Water (M4-Medium)) derived by ELENDT as stated in the OECD Guideline. As the test item contains metals, M4-Medium without EDTA (Ethylenediaminetetraacetic acid) was prepared.

Test organisms (species):

Daphnia magna

Details on test organisms:

Species Daphnia magna
Variety STRAUS
Strain Berlin
Arrival of Strain 27. Sep. 2007
Sex female
Age between 0 and 24 hours
The animals which were used in the test did not belong to the first brood of the respective parent animals.

Test type:

semi-static

Water media type:

freshwater

Total exposure duration:

21 d

Hardness:

267 - 356 mg/L CaCO3

Test temperature:

17.4 - 21.3°C

pH:

7.7- 8.7

Dissolved oxygen:

at least 8.1 mg/L

Nominal and measured concentrations:

The content of Aluminium (Al) as a component of the test item in the test solutions was determined using ICP-OES determination. All determined aluminium values were far below the limit of detection (LOD). Therefore, the determination of the biological results was based on the nominal concentrations.

Details on test conditions:

Duration: 21 days
Loading: 80 mL/animal, animals were kept individually
Replicates: 10 replicates/treatment
Treatments: 4.6 / 10 / 22 / 46 / 100 mg/L nominal concentration
Blank Control: dilution water
Lighting: 1000 Lux
Aeration: none
Feeding: 0.20 mg organic carbon/animal/working day, double amount on Friday, the amount of carbon is based on photometric measurement (linear correlation between absorption at 440 nm and measured DOC concentration).

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Key result

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Details on results:

Significant decrease in the reproduction of the daphnia could not be observed in any treatment. Therefore, only the highest test concentration was used for evaluation of the results.

Results with reference substance (positive control):

Because the number of offspring in the highest concentrated treatment was higher than in the control, no statistical evaluation had to be performed.

Reported statistics and error estimates:

Because the number of offspring in the highest concentrated treatment was higher than in the control, no statistical evaluation had to be performed.

 

 Reproduction

    Offspring

 

	Nominal Concentration in mg/L
	BlankControl	4.6mg/L	10mg/L	22mg/L	46mg/L	100mg/L
1	77	105	77	84	M	67
2	83	94	73	90	63	116
3	101	96	94	91	85	133
4	90	80	67	99	66	M
5	66	139	99	87	122	M
6	76	101	75	89	109	88
7	85	79	54	72	101	100
8	96	127	81	75	133	96
9	113	65	76	99	110	124
10	91	M	92	90	127	105
Mean	88	98	79	88	102	104
SD	14	23	13	9	26	21
RSD	15.44	23.75	17.09	10.07	25.06	20.27

SD=standard deviation

RSD=relative standard deviat M = mortality of parent animal

Validity criteria fulfilled:

yes

Conclusions:

The following results were determined for the test item Silicic acid, Aluminium Magnesium Sodium Salt:
NOEC ≥ 100 mg/L
LOEC > 100 mg/L

Description of key information

The following results were determined for the read-across test item Silicic acid, aluminum magnesium sodium salt (CAS 12040-43-6, SMAS):

NOEC (21-day reproduction) ≥ 100 mg/L
LOEC (21-day reproduction) > 100 mg/L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

NOEC

Effect concentration:

>= 100 mg/L

Additional information

Since no studies investigating the long-term toxicity of amorphous Silicic acid, aluminum sodium salt (CAS 1344-00-9, NAS) to invertebrates are available, a read-across to the structurally related substance Silicic acid, aluminum magnesium sodium salt (CAS 12040-43-6, SMAS) was conducted. This read-across is justified within the analogue justification in IUCLID Section 13.

Furthermore, it is assumed that the freshwater results are also applicable to marine life, i.e. no long-term aquatic toxicity is expected from exposure to synthetic amorphous Silicic acid, aluminum sodium salt (CAS 1344-00-9, NAS).