Platinum dioxide

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:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP-status not known, guideline not known, acceptable with restrictions, limitations in design and/or reporting, but otherwise adequate for assessment, published in peer-reviewed literature

Qualifier:

no guideline followed

Principles of method if other than guideline:

A standard guideline was not followed, but the study is well documented and the method used is considered to be acceptable.

GLP compliance:

not specified

Analytical monitoring:

no

Vehicle:

not specified

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Fresh stock solutions were prepared in lake water.
- Controls: unfiltered lake water

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Source: University of Michigan
- Age of parental stock (mean and range, SD): not reported
- Age of tested organisms: 12 ± 12 hours old
- Feeding during test
- Food type: suspension of food prepared by mixing 0.5 g of powdered dried grass and 10 g of enriched trout-fry granules to 250 mL of Lake Superior water. Additionally, daphnids obtained some nutrients from bacteria, algae and detritus in the water.
- Amount: 1 mL/L
- Frequency: once weekly during testing

ACCLIMATION
- Acclimation period: not reported
- Acclimation conditions (same as test or not): not reported
- Type and amount of food: suspension of food prepared by mixing 0.5 g of powdered dried grass and 10 g of enriched trout-fry granules to 250 mL of Lake Superior water.
- Feeding frequency: twice weekly
- Health during acclimation (any mortality observed): not reported

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

45300 μg/L (mean)

Dissolved oxygen:

In general, near saturation at all times.
At dawn: approximately 9 mg/L
Late in the day: sometimes slightly exceeded saturation because of photosynthesis by algae in the test medium

Nominal and measured concentrations:

12 concentrations tested - values not specified.

Details on test conditions:

TEST SYSTEM
- Test vessel: 250-mL beakers containing 200 mL of water and covered with a pane of glass
- Aeration: not reported
- Renewal of test solution: at the beginning of each week
- 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: unfiltered water of Lake Superior
- Total Hardness: 45300 μg/L (mean)
- Metals: Mean values: chloride 1217 μg/L, sodium 1130 μg/L, calcium 13695 μg/L, magnesium 3123 μg/L, potassium 534 μg/L, strontium 16 μg/L, barium 14 μg/L, iron 23 μg/L, zinc 0.78 μg/L, nickel < 0.5 μg/L, copper 1.51 μg/L, cobalt < 0.5 μg/L, mercury < 0.01 μg/L, cadmium < 0.1 μg/L. Range of values: manganese 0.2 - 11.5 μg/L, chromium 2 - 20 μg/L, aluminum 1 - 26 μg/L, lead 7 - 20 μg/L
- Alkalinity: 42300 μg/L (mean)
- Intervals of water quality measurement: measurement of pH was made when the medium was added and 1 week later when the medium and test item were replaced by fresh solutions. Analytical measurements were made for Na, Ca, Mg, Fe, Mn, Zn and Cd at the time of addition of test medium and 1 week later. Chemical characteristics of Lake Superior Water were monitored using atomic absorption spectroscopy.

OTHER TEST CONDITIONS
- Photoperiod: not reported
- Light intensity: approximately 115 footcandles at air-water interface

EFFECT PARAMETERS MEASURED: Survival of the animals was noted after 1, 2 and 3 weeks. At the end of 3 weeks the surviving organisms were weighed and prepared for protein and gluatamic oxalacetic transaminase (GOT) analyses. Reproduction was assessed by counting the young produced each week. The young Daphnids were also counted and discarded at each test medium renewal and at the end of the test.

Reference substance (positive control):

not specified

Key result

Duration:

21 d

Dose descriptor:

other: EC16

Effect conc.:

14 µg/L

Nominal / measured:

not specified

Conc. based on:

element

Remarks:

Pt

Basis for effect:

reproduction

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

7 µg/L

Nominal / measured:

estimated

Conc. based on:

element

Remarks:

Pt

Basis for effect:

reproduction

Remarks on result:

other: Determined as EC16/2

Duration:

21 d

Dose descriptor:

LC50

Effect conc.:

520 µg/L

Nominal / measured:

not specified

Conc. based on:

element

Remarks:

Pt

Basis for effect:

mortality

Remarks on result:

other: 95% Confidence Limits: 437 - 619 μg/L

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

82 µg/L

Nominal / measured:

not specified

Conc. based on:

element

Remarks:

Pt

Basis for effect:

reproduction

Details on results:

- A mean percentage deviation decrease from control means of 12, 13 and 20 % were measured at 62 μg Pt/L for weight of animals, total protein content and GOT activity of Daphnia magna, respectively, after 3 weeks of wexposure to the test item.
- The 16 % reproductive-impairment concentration was given since it represented a minimal reproducible value below which the variability in reproduction could not be detected from controls.

Reported statistics and error estimates:

Results were statistically evaluated with the method of Litchfield and Wilcoxon (1949) for establishing approximations of the 95 % confidence limits for survival. Reproductive effects were analysed in a similar manner excluding confidence limits.

Validity criteria fulfilled:

not specified

Conclusions:

The 21-day LC50 of hexachloroplatinic acid for Daphnia magna was determined to be 520 μg Pt/L (1092 μg test item/L). The 21-day EC50 and EC16 of hexachloroplatinic acid for the reproduction-impairment to Daphnia magna were determined to be 82 μg Pt/L (172.26 μg test item/L), and 14 μg Pt/L (29.35 μg test item/L), respectively. The NOEC was estimated to be 7.0 μg Pt/L (14.70 μg test item/L), given by the ratio of EC16/2.

Executive summary:

The chronic toxicity of hexachloroplatinic acid to Daphnia magna was assessed in the publication by Biesinger and Christensen (1972), where the effects of various metals on survival, growth, reproduction and metabolism of Daphnia magna were investigated. The study is acceptable with restrictions, although the guideline and the GLP-status are both unknown.

A semi-static test of 21 days was conducted. Twelve concentrations of the test item were tested. The 21-day LC50 of hexachloroplatinic acid for Daphnia magna was determined to be 520 μg Pt/L (1092 μg test item/L). The 21-day EC50 and EC16 of hexachloroplatinic acid for the reproduction-impairment to Daphnia magna were determined to be 82 μg Pt/L (172.26 μg test item/L), and 14 μg Pt/L (29.35 μg test item/L), respectively. The NOEC was estimated to be 7.0 μg Pt/L (14.70 μg test item/L), given by the ratio of EC16/2.

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 NOEC for reproduction impairment with D. magna was determined at 7 µg Pt/L. This is the lowest chronic threshold identified with Platinum(IV) substances, and this value serves as basis for chronic ERV derivation.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

7 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.

The chronic toxicity of hexachloroplatinic acid to Daphnia magna was assessed in the publication by Biesinger and Christensen (1972), where the effects of various metals on survival, growth, reproduction and metabolism of Daphnia magna were investigated. The study is acceptable with restrictions, although the guideline and the GLP-status are both unknown. A semi-static test of 21 days was conducted. Twelve concentrations of the test item were tested. The 21-day LC50 of hexachloroplatinic acid for Daphnia magna was determined to be 520 μg Pt/L (1092 μg test item/L). The 21-day EC50 and EC16 of hexachloroplatinic acid for the reproduction-impairment to Daphnia magna were determined to be 82 μg Pt/L (172.26 μg test item/L), and 14 μg Pt/L (29.35 μg test item/L), respectively. The NOEC was estimated to be 7.0 μg Pt/L (14.70 μg test item/L), given by the ratio of EC16/2.