Cerium

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

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 203 (Fish, Acute Toxicity Test)

Version / remarks:

and EU Method C.1 (Acute Toxicity for Fish)

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: For the measurement of the concentration of cerium in this semi-static test, the following samples were taken: triplicate samples from the freshly prepared test medium and control just before test start (Day 0) and on the last day of preparation of the test medium (Day 3), triplicate samples from the aged test medium and control at the end of the first test medium renewal period (Day 1) and at the end of the last renewal period (Day 4)
- Sampling method: All samples were taken from the approximate center of the aquaria without mixing of the test medium.
- Sample storage conditions before analysis : immediately after sampling, the samples were acidified with 3% nitric acid (HNO3, 65% Suprapur®, Merck) to stabilize the test item during storage period. Then the samples were deep frozen and stored at about -20°C until analysis.

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 with the water content of the test item). The dispersion with the loading rate of 152 mg/L was prepared by dispersing 1.520 to 1.522 g of the test item in 10 L 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. The test medium was prepared just before the start of the test and prior to the test medium renewals.
- Differential loadings: No (limit test)
- Controls: blank (test water without test item)
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no data

Test organisms

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Source: P. Hohler, trout breeding station, Zeiningen (Switzerland)
- Age at study initiation (mean and range, SD): no data
- Length at study initiation (length definition, mean, range and SD): 4.7 +/- 0.1 cm (no data on range)
- Weight at study initiation (mean and range, SD): 0.87 +/- 0.07 g (no data on range)
- Feeding during test : no

ACCLIMATION
- Acclimation period: the fish were held in the laboratory for 3 weeks without any medication. Prior to the test they were acclimated for 1 week to the test water and temperature.
- Type and amount of food: During holding and acclimatization until one day before the start of the test, the fish were fed with a commercial fish diet (Hokovit 502)
- Feeding frequency: no data
- Health during acclimation (any mortality observed): During holding and acclimatization no fish died in the test fish batch and all fish were healthy.

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Post exposure observation period:

no

Test conditions

Hardness:

214 mg/L as CaCO3

Test temperature:

13°

pH:

8.5 all along the test

Dissolved oxygen:

between 9.3 and 9.9 mg/L

Salinity:

not applicable

Nominal and measured concentrations:

Nominal concentration : 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type : open
- Material, size, headspace, fill volume: glass aquarium with 10 L of test medium
- Aeration: The test water was aerated prior to the preparation of the test media until oxygen saturation was reached. During the test period, the test medium and the control were slightly aerated.
- Type of flow-through (e.g. peristaltic or proportional diluter): none (semi-static test)
- Renewal rate of test solution (frequency/flow rate): every day
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): no vehicle control
- Biomass loading rate: 0.61 g fish wet weight / L


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: local tap water (non chlorinated well water of drinking quality) reduced for total hardness by ion exchange
- Total organic carbon: no data
- Particulate matter: no data
- Metals (µg/L): Cd < 0.5, As < 3, lead < 3, mercury < 1, selenium < 3, copper < 4
- Pesticides (µg/L): lindane, heptachlor, malathion, DDT total, dieldrin < 0.05
- Chlorine: no data
- Alkalinity: no data
- Ca/mg ratio: no data
- Conductivity: no data
- Bacteriological parameters: at the time of sampling, the tested parameters met the requirement for drinking water
- Culture medium different from test medium: Prior to the test start, fish were acclimated for one week to the test water and temperature.
- Intervals of water quality measurement: The water temperature, pH-values and oxygen concentrations were measured in the single test concentration and in the control at the start of the test and once every day during the test in the freshly prepared and old test media and the control.
At the same dates, the appearance of the test medium was recorded. The total hardness of the water used in the test was measured at the start of the test in the control.


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours light and 8 hours darkness with a 30-minute transition period
- Light intensity: 50- 500 lux

EFFECT PARAMETERS MEASURED :
The test fish were observed after approximately 2, 24, 48, 72 and 96 hours test duration for mortality and visible abnormalities.
The NOELR and the LL0 were determined directly from the raw data. The LOELR, the LL100 and the LL50 at the observation times could not be quantified due to the absence of a toxic effect of the test item at the tested concentration.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: not applicable (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):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Effect concentrations 2

Duration:

96 h

Dose descriptor:

NOELR

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

BIOLOGICAL RESULTS
- Behavioural abnormalities: none
- Observations on body length and weight: none
- Other biological observations: none
- Mortality of control: none
- Other adverse effects in control: none
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: none
- Effect concentrations exceeding solubility of substance in test medium: no


APPEARANCE OF THE TEST MEDIUM
No remarkable observations were made concerning the appearance of the test medium. It was a clear solution throughout the test period.

ANALYTICAL MONITORING
The analytically measured concentrations of cerium in the test medium samples taken at the start and at the end of the first and the last test medium renewal periods were between 3 and 4 µg/L (mean = 3.4 µg/L corresponding to 5.6 µg of cerium carbonate /L).

Results with reference substance (positive control):

Not tested

Reported statistics and error estimates:

Reported statistics and error estimates: not necessary as no toxicity was observed.

Any other information on results incl. tables

Sublethal observations / clinical signs:

Mortality and visible abnormalities observed in the test fish :

Loading rate (mg/L)	Mean measured Concentration of cerium carbonate (µg/L)	Number of abnormal and dead fish / number of dead fish
		Observation time
		2 hours	24 hours	48 hours	72 hours	96 hours
Control	< 1.6*	0 / 0	0 / 0	0 / 0	0 / 0	0 / 0
Undiluted filtrate (100 mg/L)	5.6	0 / 0	0 / 0	0 / 0	0 / 0	0 / 0
LL50		> 100 mg/L based on loading rate # > 5.6 µg/L based on mean measured concentration of cerium carbonate

 

#: 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, dicerium tricarbonate, had no acute toxic effects on rainbow trout up to the solubility limit in the test water, at the loading rate of 100 mg/L.

Executive summary:

The acute toxicity of the test item, dicerium tricarbonate, to rainbow trout (Oncorhynchus mykiss) was determined in a 96-hour semi-static test with a daily test medium renewal according to the EU Commission Directive 92/69/EEC, Part C.1 (1992), and the OECD Guideline for Testing of Chemicals No. 203 (1992).

Fish were exposed to control and test chemical at a loading rate of 100 mg/L for 96h. Mortality and visible abnormalities were observed daily. No mortality or other visible abnormalities were observed during the test.

The 96-hour NOELR and the 96-hour LL50 of dicerium tricarbonate to rainbow trout were thus determined to be > 100 mg/L (measured test item concentration of 5.6 µg/L).

In conclusion, the test item dicerium tricarbonate had no acute toxic effects on rainbow trout up to the solubility limit in the test water, at the loading rate of 100 mg/L.