Cerium

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

from 11 SEPT 2006 to 30 JULY 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study performed according to an international guideline and according to GLP.

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 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

and EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Dicerium tricarbonate

EC Number:

208-655-6

EC Name:

Dicerium tricarbonate

Cas Number:

537-01-9

IUPAC Name:

dicerium tricarbonate

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: triplicates samples from the test medium (loading rate = 100 mg/L) and from the control were sampled just before test start and after 48 hours.
- Sampling method: no data
- Sample storage conditions before analysis: 3% nitric acid (HNO3, 65% Suprapur®, Merck) were added to stabilize the test item during the storage period. Then the samples were deep frozen and stored at about -20°C.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: an undiluted filtrate of a supersaturated dispersion with the loading rate of 152 mg/L was tested (corresponding to the loading rate of 100 mg/L when corrected for the water content of the test item).
The dispersion with the loading rate of 152 mg/L was prepared by dispersing 76.0 mg of the test item in 500 mL of test water. The test item was mixed into the test water as homogeneously as possible using ultrasonic treatment for 15 min and intense stirring. The dispersion was stirred on a magnetic stirrer at room temperature in the dark for seven days. After the stirring period, the dispersion was filtered through a membrane filter (0.45 µm). The undiluted filtrate of the dispersion was used as the test medium.
- Differential loadings: No (limit test)
- Controls: controls : blank (test water without test item)
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no data

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain: clone defined as clone 5
- Source: supplied in 1992 by University of Sheffield/UK
- Age at study initiation : 6-24 hours, not first brood progeny
- Weight and length at study initiation: no data
- Method of breeding: bred in RCC since 1992 in reconstituted water of the quality identical to the water used in the tests and under temperature and light conditions identical to those of the test.
- Feeding during test: No

ACCLIMATION
no

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

none

Test conditions

Hardness:

2.5 mmol/L (= 250 mg/L as CaCO3)

Test temperature:

20°C

pH:

7.8

Dissolved oxygen:

between 8.5 and 8.8 mg/L

Salinity:

not applicable

Nominal and measured concentrations:

Nominal concentration: 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type : 100 mL glass beakers
- Material, size, headspace, fill volume: vessels filled with 50 mL of test medium
- Aeration: The test water was aerated prior to the start of the study until oxygen saturation was reached.During the test period, the test water was not aerated.
- Type of flow-through (e.g. peristaltic or proportional diluter): none (static test)
- Renewal rate of test solution (frequency/flow rate): no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: 2 mL of medium per daphnia

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted test water : analytical grade salts dissolved in purified water
- Alkalinity: 0.8 mmol/L
- Ca/Mg ratio (mol): 4:1 (based on molarity)
- Na / K ratio: 10:1 (based on molarity)
- Culture medium different from test medium: no
- Intervals of water quality measurement: The pH values, the dissolved oxygen concentrations and the temperature were determined at the start and at the end of the test in the control and the test medium. The appearance of the test medium was also recorded at the start of the test and after 24 and 48 hours.
- No further data

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: a 16 hour light to 8 hour dark with a 30 minute transition period.
- Light intensity: between 470 and 640 lux

EFFECT PARAMETERS MEASURED :
The daphnids were observed for immobility after 24 and 48 hours of exposure (daphnids not being able to swim within 15 seconds after gentle agitation of the test beaker are considered to be immobilized).
The NOELR and EL0 were determined directly from the raw data. The EL50 and EL100 could not be determined due to the absence of a toxic effect of the test item in this test.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: not relevant (limit test)
- Range finding study: yes
- Test concentrations: No data
- Results used to determine the conditions for the definitive study: no mortality at the undiluted loading rate.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

LL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The analyticaly measured concentrations of cerium in the test medium samples taken at the start and at the end of the test were between 2 and 3 µg of Cerium/l (mean = 3.1 µg/L corresponding to 3.5 µg of cerium carbonate /L).
No remarkable observations concerning the appearance of the test medium.

Results with reference substance (positive control):

Results with reference substance valid? yes
- 48h-EC50: 0.67 mg/L (acceptance range : 0.53 - 1.1 mg/L) (potassium dichromate)

Reported statistics and error estimates:

none

Any other information on results incl. tables

Effect of CERIUM CARBONATE HUMIDE on the Mobility ofDaphnia magna: Treatment (Loading rate) #   Mean measured Concentration of cerium carbonate (µg/L) No. of daphnids tested Immobilized daphnids after 24 hours                  No.                   % Immobilized daphnids after 48 hours                   No.                   % Control < 1.6* 20 0 0 0 0 Undiluted filtrate (100 mg/L) 3.5 20 0 0 0 0

 

# : loading rate corrected for the water content of the test item

* : limit of quantification of 1 µg cerium/L, corresponding to 1.6 µg cerium carbonate/L

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The test item had no acute toxic effects on Daphnia magna up to its solubility limit in the test water at the loading rate of 100 mg/L .

Executive summary:

The 48hr-acute toxicity of cerium carbonate to Daphnia magna was studied under static conditions according to the EU Commission Directive 92/69/EEC, Part C.2 (1992) and the OECD Guideline for Testing of Chemicals, N°202 (2004). Daphnids were exposed to control and test chemical at nominal concentration of 100 mg of dry substance /L (loading rate) for 48 hr. Mortality/immobilization were observed daily. In the control and at the loading rate of 100 mg/L, no immobilized test organisms were observed during the test period of 48 h. Thus, the 48 hour LL50 was > 100 mg/L and the 48h NOEC were >= 100 mg/L.