Tetrasodium enneatitanium icosaoxide hydrate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

8.12.2014-20.2.2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study was performed according to the recommended Guidelines (OECD Guidelines for Testing of Chemicals (April 2004) No 202 "Daphnia sp., Acute Immobilisation Test" and Method C.2 of Commission Regulation (EC) No. 440/2008) and GLP.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

April 2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

(EC) No. 440/2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Certificate is included in the study report.

Analytical monitoring:

yes

Details on sampling:

- Concentrations: less than LOQ (0.001 mg/L)
- Sample storage conditions before analysis: The samples were stored frozen prior to analysis.

Vehicle:

no

Details on test solutions:

See Any other information on methods and materials for more information.

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Adding test item (1100 mg) to test water (11 L). Stirring solution for 48 h with propeller (1500 rpm). Filtration through a 0.2 μm Sartorius Sartopore filter (approximately 2 liters discarded in order to pre-condition the filter)
- Evidence of undissolved material (e.g. precipitate, surface film, etc): Substance difficultly dissolved in water.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- strain: 1st instar
- Source: In-house laboratory cultures.
- Age at study initiation (mean and range, SD): Less than 24 hours old
- Feeding during test: No feeding during test

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

No post exposure observation period.

Hardness:

250 mg/L as CaCO3

Test temperature:

21 °C

pH:

pH of 7.8 ± 0.2

Dissolved oxygen:

Dissolved oxygen concentrations were recorded at the start and termination of the test. Dissolved oxygen concentration were measured using a Hach Flexi handheld meter.
Control: 0 hours: 9.0 mg O2/L; 48 hours: 8.7 mg O2/L
Test solution: 0 hours: 8.9 mg O2/L; 48 hours: 8.7 mg O2/L

Nominal and measured concentrations:

Nominal concentration of 100% v/v saturated solution. Measured test concentrations: < 0.0010 mg/L titanium.

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL glass jars
- Type: covered
- Material, size, headspace, fill volume: Glass jars, 250 mL. 200 mL test preparation.
- Aeration: Test preparation was aerated before test started. No aeration during test.
- Renewal rate of test solution (frequency/flow rate): No renewal
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): Four
- No. of vessels per control (replicates): Four

TEST MEDIUM / WATER PARAMETERS (see Any other information on method and materials for more information)
- Source/preparation of dilution water: Reconstituted water (ISO medium). Test item was dissolved directly into the test medium.
- Culture medium different from test medium: Elendt M7 medium
- Intervals of water quality measurement: Water temperature was recorded daily throughout the test. Dissolved oxygen concentrations and pH were recorded at the start and termination of the test.

OTHER TEST CONDITIONS
- Photoperiod: 16 hours of light and 8 hours of darkness with 20 minute dawn and dusk transition periods
- Light intensity: (424 to 486 lux)

TEST CONCENTRATIONS
- Justification for using less concentrations than requested by guideline: The main test was performed with 1 test concentration as a limit test. Preliminary solubility work conducted indicated that the test item was practically insoluble in water using traditional methods of preparation e.g. ultrasonication. Based on this information the test item was categorized as being a ‘difficult substance’ as defined by the OECD Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures (OECD 2000). Therefore a media preparation trial was conducted in order to determine the solubility of the test item under test conditions. Due to the low solubility of the substance, it was anticipated that the toxicity response in the daphnias would be low. Therefore only four test concentration were used for the range-finding test.
- Range finding study: with the following test concentrations.
- Test concentrations: 0.10, 1.0, 10 and 100% v/v saturated solution.
- Results used to determine the conditions for the definitive study: No immobilization was observed at the test concentrations of 0.10, 1.0, 10 and 100% v/v saturated solution. Based on this information, a single test concentration of four replicates, of 100% v/v saturated solution was selected for the definitive test.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate. The positive control was conducted between 21 July 2014 and 23 July 2014.

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 other: % v/v saturated solution.

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

100 other: % v/v saturated solution

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: no immobilization
- Abnormal responses: No abnormal responses
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No observations

Results with reference substance (positive control):

- Results with reference substance valid. Yes
- EC50/LC50: EC50: 24 hours: 1 mg/L and 48 hours: 0.58 mg/L
- Other:
NOEC: 24 hours: 0.56 mg/L and 48 hours: 0.32 mg/L
LOEC: 24 hours: 1.0 mg/L and 48 hours: 0.56 mg/L

Reported statistics and error estimates:

An estimate of the EC50 values was given by inspection of the immobilization data.

Table 1. Cumulative Immobilization Data in the Definitive Test

Nominal Concentration (% v/v Saturated Solution)		Cumulative Immobilized Daphnia (Initial Population: 5 Per Replicate)
		24 Hours			48 Hours
		No. Per Replicate	Total	%	No. Per Replicate	Total	%
Control	R1	0	0	0	0	0	0
	R2	0			0
	R3	0			0
	R4	0			0
100	R1	0	0	0	0	0	0
	R2	0			0
	R3	0			0
	R4	0			0

Table 2. Water Quality Measurements

Nominal Concentration (% v/v Saturated Solution)		0 hours			24 hours	48 hours
		pH	mg O2/L	T °C	T °C	pH	mg O2/L	T °C
Control	R1	8	9	21	21	7.8	8.7	21
100	R1	8.3	8.9	21	21	7.9	8.7	21

Validity criteria fulfilled:

yes

Remarks:

Validity criteria as in OECD

Conclusions:

The acute toxicity of the test item to the freshwater invertebrate Daphnia magna has been investigated and gave a 48-Hour EC50 value of greater than 100% v/v saturated solution. The No Observed Effect Concentration was 100% v/v saturated solution. This study showed that there were no toxic effects at saturation.

Executive summary:

A study was performed to assess the acute toxicity of the test item to Daphnia magna. The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (April 2004) No 202, "Daphnia sp., Acute Immobilisation Test" referenced as Method C.2 of Commission Regulation (EC) No. 440/2008.

Preliminary solubility work conducted indicated that it was not possible to obtain a testable solution of the test item using traditional methods of preparation e.g. ultrasonication.

Following a preliminary range-finding test, twenty daphnids (4 replicates of 5 animals) were exposed to an aqueous solution of the test item at a nominal concentration of 100% v/v saturated solution for 48 hours at a temperature of 21 °C under static test conditions.

Immobilization and any adverse reactions to exposure were recorded after 24 and 48 hours.

Analysis of the test preparations at 0 and 48 hours showed measured titanium concentrations of less than the limit of quantification (LOQ) of the analytical method employed were obtained which was determined to be 0.0010 mg/L. This does not infer that no titanium was in solution, just that any titanium present was at a concentration of less than the LOQ.

Exposure of Daphnia magna to the test item gave EC50 values of greater than 100% v/v saturated solution. The No Observed Effect Concentration was 100% v/v saturated solution

This study showed that there were no toxic effects at saturation.

Description of key information

Static 48-hour test for freshwater invertebrate Daphnia manga: EC50 > 100 % v/v saturated solution, NOEC = 100 % v/v saturated solution (OECD 202, EU Method C.2, GLP)

Additional information

The acute toxicity of the test item to the freshwater invertebrate Daphnia magna has been investigated and gave a 48-Hour EC50 value of greater than 100% v/v saturated solution. The No Observed Effect Concentration was 100% v/v saturated solution. This study showed that there were no toxic effects at saturation.

However, based on the water solubility test the substance is highly insoluble in water, and can be regarded as a poorly soluble substance. Nevertheless, long-term aquatic studies are not considered necessary due to exposure considerations and aquatic toxicity being unlikely to occur. The substance is only used industrially in highly controlled industrial environments, mainly nuclear facilities and equivalent environments, where all necessary risk management measures are in place. It is not used professionally nor by consumers, nor in any context where its use could be considered as widely dispersive.

During manufacture of the substance, water that has been in contact with the substance undergoes ultrafiltration. The permeate is further pretreated with neutralization, flocculation and clarification before release into the sewage system.

The substance is only used in the industry very occasionally and batch-wise, in small amounts at a time. The downstream users are advised to treat any rinsing waters of the substance through a filtering membrane or by means of settling in the rinsing vessel before release. The ion-exchange columns, where the substance is washed and used, have e.g. a 32 or a 40 µm filter at the column outlets, at both ends of the column to take into account backwash as well. The filter prevents the granular substance from escaping the column into the washing waters or into the treated waters.

The used columns are treated as radioactive or as hazardous waste. Any unused substance is treated as hazardous waste. As such, emissions of the substance to the aquatic compartment during manufacture or during end use are negligible.