Platinum dioxide

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:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP-compliant, guideline study, available as unpublished report, fully adequate for assessment

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

The age of test organisms at test start was of maximum 29 hours old, instead of less than 24 hours old.

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

yes

Remarks:

The age of test organisms at test start was of maximum 29 hours old, instead of less than 24 hours old.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Duplicate sampling from all test concentrations and controls were taken at the start of the test and at the end of the test. All samples were stored in a refrigerator prior to analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A stock solution was prepared by dissolving 20 mg test item into 200 mL test water (100 mg/L) by intense stirring for 10 minutes. Afterwards, 4 mL of this stock solution were diluted to 200 mL with test water to prepare a solution of 2 mg/L. Then, this solution was diluted with test water to prepare test media.
- Controls: test water without addition of the test item
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): not reported

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain/clone: Straus, Clone 5
- Source: Umweltbundesamt, Institut für Wasser-, Boden- und Lufthygiene, Berlin, Germany
- Age of parental stock: not reported
- Age of test organisms: 22.5 hours to 29 hours
- Feeding during test: none

ACCLIMATION
- Acclimation period: 6 hours and 40 minutes
- Acclimation conditions (same as test or not): same as test
- Type and amount of food: not reported
- Health during acclimation (any mortality observed): not reported

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

None

Hardness:

250 mg/L as CaCO3

Test temperature:

21 °C

pH:

7.0 - 7.6

Dissolved oxygen:

8.4 - 9.0 mg/L

Nominal and measured concentrations:

Nominal concentrations: 20, 29, 42, 62 and 90 μg test item/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL glass beakers containing 50 mL of test solution
- Aeration: not reported
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted water
- Total Hardness: 250 mg/L as CaCO3
- Alkalinity: 0.8 mmol/L
- Ca/mg ratio: 4 : 1 (based on molarity)
- Conductivity: < 5 μS/cm
- Intervals of water quality measurement:

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light and 8 hours dark
- Light intensity: 60 - 100 lux

EFFECT PARAMETERS MEASURED: The immobility or mortality of Daphnia was determined every 24 hours. Daphnia were considered immobile if they were unable to swim for 15 seconds after gentle agitation.

VEHICLE CONTROL PERFORMED: no

RANGE-FINDING STUDY
- Test concentrations: not reported
- Results used to determine the conditions for the definitive study: not reported

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

60.8 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % Confidence Intervals: 56.6 - 65.3 μg test item/L

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

20.48 µg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

pt

Basis for effect:

mobility

Remarks on result:

other: 95 % Confidence Intervals: 19.06 - 21.99 μg Pt/L

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

42 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

14.15 µg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

Pt

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

62 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

20.88 µg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

Pt

Basis for effect:

mobility

Details on results:

After 48 hours of exposure, the toxicity of the test item to Daphnia magna increased. In the control and up to 42 μg test item/L, no significant immobility or mortality or other signs of intoxication were determined. At the test concentration of nominal 62 μg test item /L, 11 organisms were found to be immobile, and at the highest test concentration of 90 μg test item/L, all organisms were immobile at the end of the test.

Reported statistics and error estimates:

The 48-hour EC50 and 95 % confidence intervals were calculated by Probit analysis. The NOEC and LOEC values were determined by Fisher's Exact Test with Bonferroni Correction (alpha is 0.05).
Statistical calculations were performed with ToxRat.

Table 1. Effect of hexachloroplatinic acid on the mobility of Daphnia magna after 24 and 48 hours of exposure.

Concentration (μg test item/L)	No. of organisms tested	No. of immobilised organisms after		% of immobilised organisms after
		24 hours	48 hours	24 hours	48 hours
control	20	0	0	0	0
20	20	0	0	0	0
29	20	0	0	0	0
42	20	0	0	0	0
62	20	0	11	0	55*
90	20	4	20	20	100*

* Statistically significant according to Fisher's Exact Test (alpha: 0.05)

Validity criteria fulfilled:

yes

Remarks:

The validity criteria were fulfilled as no Daphnia were immobilised in the control and the dissolved oxygen was greater than 3 mg/L at the end of the test

Conclusions:

Based on nominal concentrations, the 48-hour EC50 of hexachloroplatinic acid to Daphnia magna was determined to be 60.8 μg test item/L (20.48 μg Pt/L).

Executive summary:

A 48-h acute immobilisation Daphnia magna study is available for hexachloroplatinic acid. The study is reliable without restrictions, being GLP-compliant, and having followed standard guidelines (OECD 202 and EU Method C.2).

A static test system was followed. Five nominal test concentrations were used and these were analysed using Graphite furnace-AAS method. Although stock solution concentration was confirmed by analytical monitoring the test concentrations were not measured. All validity criteria were met. Based on nominal concentrations, the 48-hour EC50 of hexachloroplatinic acid to Daphnia magna was determined to be 60.8 μg test item/L (20.48 μg Pt/L). The 48-hour NOEC was determined to be 42 μg test item/L (14.15 μg Pt/L), and the 48-hour LOEC was determined to be 62 μg test item/L (20.88 μg Pt/L).

Description of key information

No experimental study is required for platinum dioxide based on the outcome of a full TDp assay (cfr.

IUCLID Section 4 'Water solubility') and the identified acute and chronic threshold values with other

water soluble platinum(IV) substances.

The 48-hour EC50 for hexachloroplatinic acid was determined at 20.48 μg Pt L^-1. This is the lowest acute threshold identified with Platinum(IV) substances, and this value serves as basis for acute ERV derivation.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

20.48 µg/L

Additional information

No experimental study is required for platinum dioxide based on the outcome of a full TDp assay (cfr.

IUCLID Section 4 'Water solubility') and the identified acute and chronic threshold values with other

water soluble platinum(IV) substances.

A 48-h acute immobilisation Daphnia magna study is available for hexachloroplatinic acid following OECD guideline 202 and EU Method C.2 (Moll and Wydra 2005). A static test system was used. Five nominal test concentrations were used and these were analysed using Graphite furnace-AAS method. The concentration of the test item could not be quantified, since all concentrations were below the LOQ. Results were therefore based on nominal concentrations. At the start of the test animals were of maximum 29-h old, instead of less than 24-h old, and this was reported as a protocol deviation. However, the experiment was still considered to be valid. The 48-hour EC50 was determined to be 60.8 μg test item L^-1 (20.48 μg Pt L^-1). The 48-hour NOEC was determined to be 42 μg test item L^-1 (14.15 μg Pt L^-1), and the 48-hour LOEC was determined to be 62 μg test item L^-1 (20.88 μg Pt L^-1).