Silicic acid, titanium salt

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25. Sep. 2006 - 02. Feb. 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP and Guideline conform

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Version / remarks:

resp. EU method C.20

Deviations:

yes

Remarks:

slightly increased temperature, temperature not within the range of +/- 1 °C

GLP compliance:

yes (incl. QA statement)

Remarks:

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

Test material

Test material information

Constituent 1

Reference substance name:

Silicic acid, titanium salt

EC Number:

255-911-8

EC Name:

Silicic acid, titanium salt

Cas Number:

42613-21-8

Molecular formula:

TiSixOy, where x and y are unspecified.

IUPAC Name:

titanium(4+) bis(oxosilanebis(olate))

Details on test material:

- Name of test material (as cited in study report): Magnapore 963
- Physical state/appearance: black powder
- Analytical purity: 98%
- Lot/batch No.: LOT 405
- Expiration date of the lot/batch: 01.09.2007
- Production date: 01.03.2006
- Homogeneity: homogenous
- Additive: Chromium(III)hydroxide, CAS No. 1308-14-1

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Details on test solutions:

A saturated solution was prepared because of the poor solubility of the test item.Therefore, a saturated suspension containing 1000 mg/L test item in dilution water was shaken for 24 h, followed by membrane filtration ( pore diameter 0.45 µm). The resulting solution was used to prepare the treatments before each solution reneval.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain/clone: STRAUS (Berlin)
- Source: LAUS GmbH (in-house culture), originally obtained from the Umweltbundesamt in Berlin
- Age of parental stock (mean and range, SD): between 0 and 24 hours
- Feeding during test
- Food type: unicellar green alga (Desmodesmus subspicatus)
- Amount: - Feeding: 0.15 mg org. carbon/animal
- Frequency: daily


ACCLIMATION: no data available

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Test conditions

Hardness:

143 - 188 mg CaCO3/L

Test temperature:

20.5 - 24.3

pH:

7.5 - 8.6

Dissolved oxygen:

7.7 - 9.9

Nominal and measured concentrations:

1, 3.2, 10, 32 and 100 % saturation

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: glass beakers (nominal volume 100 mL)
- Aeration: none
- Renewal rate of test solution (frequency/flow rate): three times a week
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10
- Biomass loading rate: 80 mL/animal, animals were held individually


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted hard water following ASTM E729-96 was used
- Total organic carbon: 150 mg CaCO3/L
- Metals: NaHCO3: 192 mg/L; CaSO4 * 2H2O: 120 mg/L; MgSO4 * 7H2O: 120 mg/L


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16/8 hours
- Light intensity:<= 2000 lux


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
The test vessels were inspected for measuring the offspring on a daily base. The newborn daphnids were counted and removed from the vessels.
Offspring of deceased parent animals was excluded from the calculation of total offspring per treatment.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

nominal load/limit of solubility

Basis for effect:

reproduction

Details on results:

Analysis of the test item concentration in the treatments before and after exposition was made, but the test item concentrations lay below the limit of detection, caused by the low water solubility. Therefore, the nominal concentrations were used for the evaluation of the results.
The test item didn't show a significant effect on the reproduction rate of the surviving daphnids at the limit of solubility.The NOEC was 1000 mg/L nominal load/limit of solublility, the LOEC and the EC50 were > 1000 mg/L nominal load/limit of solublility, respectively.

Any other information on results incl. tables

Summary of fecundity

Treatment	Total offspring	Surviving parent animals	Offspring per surviving parent animal	Inhibition of reproduction in %
Control	503	8	63	-
1%	480	8	60	5
3.2%	592	10	59	6
10%	619	10	62	2
32%	511	8	64	-2
100%	639	9	71	-13