Potassium titanium oxide (K1.88-2.13Ti8O16.94-17.07)

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:

weight of evidence

Study period:

30/06/2003-02/07/2003

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study has been performed according to OECD and EC guidelines and according to GLP principles. The restriction is due to the use of the read across approach: the test was performed not with Terracess TF but with Terracess L, a substance which is very similar in structure and physical/chemical properties.

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

(1984)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: OECD 23 (2000)

Deviations:

no

Qualifier:

according to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: duplicate samples for analysis were taken from the 5 µm filtered solution prepared at 100 mg/l (3 days stirring) and the control
- Sampling method: 20 ml from the approximate centre of the test vessel
- Sample storage conditions before analysis: All samples were stored in a deep-freeze until shipment to Solvias AG, Basel, Switzerland.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: As a consequence of the poor solubility, a supersaturated solution was prepared at nominally 100 mg/l and magnetically stirred for three days to achieve maximum solubility. The resulting dispersion was filtered through a paper filter (Schleicher and Schuell 604) to remove the larger undissolved test substance particles (ca. > 5µm). The filtered solution was used to prepare three lower concentrations (0.1, 1.0 and 10% of the filtrate.). All final solutions were clear and colourless

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain: Straus, 1820
- Source: In-house laboratory culture with a known history
- Age at study initiation (mean and range, SD): For the test selection of young daphnia with an age of < 24 hours, from parental daphnids of more than two weeks old
- Method of breeding: With new-born animals, i.e. less than 3 days old, by placing about 250 of them into 10 litres of medium in an all-glass culture vessel.
- Feeding during test: no feeding

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

250 mg CaCO3/L

Test temperature:

20.7-21.1

pH:

Blank7.9 (start) - 7.9 (end)
100% filtrate: 8.3 (start) - 8.0 (end)

Dissolved oxygen:

Blank: 8.8 (start) - 8.7 (end)
100% filtrate: 8.8 (start) - 8.7 (end)

Nominal and measured concentrations:

Nominal: A 5 µm filtered solution prepared at a loading rate of 100 mg/l (100%) and dilutions containing 0.1, 1.0 and 10% of the filtrate.
Blank control: Test medium without test substance or other additives (0 mg/l).
Measured: Analysis of the samples taken from the 5 µm filtrate prepared at a loading rate of 100 mg/l (100%) showed that measured concentrations based on Lithium and Titanium were below the detection limit of the analytical method, i.e. below 0.1 mg/l. The Potassium concentration could be measured and remained stable at approximately 3 mg/l during the 48-hour test period.
Extrapolating this concentration to the concentration of the test substance TERRACESS L resulted in a concentration of 13 mg/l (using the formula: K concentration analysed /0.76 * M K )* M TERRACESS L).

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 ml, all-glass containing 80 ml medium
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4 for the blank and the 100 mg/L filtrate and 2 for the 10, 1 and 0.1 % dilutions of 100 mg/L filtrate


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: ISO, prepared in milli-RO water
- Culture medium different from test medium: yes, M7 was used for the culturing


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours photoperiod daily


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobility (including mortality) at 24 h and 48 h.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 10
- Range finding study: this test was a combined limit and range finding test
- Test concentrations: A 5 µm filtered solution prepared at a loading rate of 100 mg/l (100%) and dilutions containing 0.1, 1.0 and 10% of the filtrate

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 3 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

element

Remarks:

Potassium

Basis for effect:

mobility

Remarks on result:

other: (> WSL)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 13 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Remarks:

Terracess L

Basis for effect:

mobility

Remarks on result:

other: (> WSL)

Details on results:

No significant immobilisation of Daphnia was observed during the test period in any of the concentrations tested

Results with reference substance (positive control):

- Results with reference substance valid? yes
The 24h-EC50 was 1.2 mg/l with a 95% confidence interval between 1.0 and 1.5 mg/l.

The 48h-EC50 was 0.60 mg/l with a 95% confidence interval between 0.52 and 0.76 mg/l

Validity criteria fulfilled:

yes

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

18 October 2000-02 May 2001

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study has been performed according to the appropriate ISO and OECD and EC guidelines and according to GLP principles. The restriction is due to the use of the read across approach: the test was performed not with Terracess TF but with Terracess P, a substance which is very similar in structure and physical/chemical properties.

Qualifier:

according to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

Version / remarks:

(1996)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

(1992)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

(1984)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- samples for analysis were taken from the blank-control and the filtered (100% filtrate) and unfiltered (100 mg/l nominal) solutions
- Sampling method: 10 mL from the approximate centre of the test vessels
- Frequency: at the start and the end of the test (t=48 h)
- Sample storage conditions before analysis: in a deep freeze until shipment to Solvias AG, Basel, Switzerland

Vehicle:

no

Details on test solutions:

Supersaturated solutions were prepared at nominally 100 mg/L and magnetically stirred for three days. Two of the solutions were filtered through a paper filter to remove the larger undissolved test substance particles (ca. > 5 µm). The filtered solution was used to prepare three lower concentrations (0.1, 1 and 10%). The third solution was not filtered and used as such (100 mg/L nominal).

The unfiltered solution (100 mg/L nominal) was a turbid whitish dispersion with undissolved test substance particles.
The undiluted filtered solution (100% filtrate) was slightly turbid, while the dilutions of the filtrate were clear and colourless.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Source: In-house laboratory culture with a known history
- Age at study initiation: < 24 hours.
- Method of breeding: With newborn daphnids, i.e. less than 3 days old, by placing about 250 of them into 10 litres of medium in an all-glass culture vessel
- Feeding during test: no feeding

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

No post exposure observations

Hardness:

250 mg CaCO3/L

Test temperature:

20.5-21.4°C

pH:

8.0-9.0

Dissolved oxygen:

7.4-9.3 mg/L

Nominal and measured concentrations:

Measured concentrations of Terracess P (calculated from the measured Titanium concentrations)

Blank control: below the limit of quantification

100% filtrate: 69912 µg/L (t=0) - 54/644 µg/L (t=48) (duplicate measurements)

100 mg/l nominal : 9677 µg/L (t=0) - 97 µg/L (t=48)

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 ml, all-glass
- Aeration: no aeration of the test solutions
- No. of organisms per vessel: 10 per vessel containing 80 ml of the solution
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Adjusted ISO medium
- Culture medium different from test medium: yes for culturing M7 medium is used

OTHER TEST CONDITIONS
- Adjustment of pH: 8.0 ± 0.2
- Photoperiod: 16 hours daily

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): immobility (including mortality) daily

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 10
-Test concentrations: 0, 0.1, 1, 10 and 100% of the filtrate + 100 mg/l nominal (not filtered)

TEST:
The study was a combined limit/range finding test

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 23 536 µg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

element

Remarks:

titanium

Basis for effect:

mobility

Details on results:

No immobility was observed in the control or any of the test concentrations.

Results with reference substance (positive control):

- Results with reference substance valid: Yes
- Mortality after 48h: 0% at 0.10 mg/L; 0% at 0.18 mg/L; 0% at 0.32 mg/L; 0% at 0.56 mg/L; 100% at 1.0 and 1.8 mg/L
- 48h-EC50 was 0.75 mg/l with a 95% confidence interval between 0.56 and 1.0 mg/L

Validity criteria fulfilled:

yes

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Justification for type of information:

1. HYPOTHESIS FOR THE CATEGORY APPROACH (ENDPOINT LEVEL)
Please see attached justification.
2. CATEGORY APPROACH JUSTIFICATION (ENDPOINT LEVEL
Please see attached justification.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 13 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Reults based on read across substance Terracess L

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 23 536 µg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

element

Basis for effect:

mobility

Remarks on result:

other: Results based on read across substance Teracess P

Description of key information

The 48 hr EC50 for Daphnia magna exceeds the maximum solubility of the substance in water in studies on two similar substances. Therefore the weight of evidence shows that Terracess TF will not be toxic to Daphnia magna.

Additional information

Owing to the extremely poor solubility of TERRACESS L in water, concentration levels toxic for Daphnia magna could not be reached. Therefore, the 48h-EC50 for Daphnia magna exceeded the maximum solubility of TERRACESS L in water at a loading rate of 100 mg/1, the regulatory limit concentration.

Owing to the extremely poor solubility of TERRACESS P in water, concentration levels toxic for crustaceans could not be reached. Therefore, the 48h-EC50 for Daphnia exceeded the maximum solubility of TERRACESS P in water at a loading of 100 mg/1, the regulatory limit concentration.