Reaction mass of Dicerium trisulfide and Dilanthanum trisulfide

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Remarks:

Constituent of the reaction mass

Adequacy of study:

key study

Study period:

From 03 February 1997 to 09 June 1997

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study scored as Klimisch 2 because not performed on the registered substance itself but on one of its constituent

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

yes

Remarks:

only 4 loading rates were tested without any justification within the report. As no effect was observed at the highest loading rate, there is no incidence of using only 4 loading rates.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Dicerium trisulphide

EC Number:

234-603-7

EC Name:

Dicerium trisulphide

Cas Number:

12014-93-6

Molecular formula:

Ce2S3

IUPAC Name:

Dicerium trisulphide

Test material form:

solid: particulate/powder

Remarks:

powder

Details on test material:

- Name of test material: Sulfure de cérium

Sampling and analysis

Analytical monitoring:

yes

Remarks:

Inductively Coupled Plasma - Mass Spectrometry (ICP - MS)

Details on sampling:

- Concentrations: 0 - 1 - 10 - 32 - 100 mg/L nominal loading rates
- Sampling method: 50 mL plastic syringe or 10 mL plastic pipette were used to collect the different samples. Different samples were taken:
* Samples taken during the preparation of the test solution; that is after 6 days (144 hours) of stirring.
* Samples taken at the end of the preparation of the test solution; that is after 7 days (168 hours) of stirring. These samples were thus collected just before fish exposure. Therefore, the corresponding analytical measurements can be assimilated to t = 0.
* Samples taken afeter 48 hours of daphnid exposure (t = 48). It has to be noticed that this 48-hour solution was kept in the same conditions than the solution used for exposure but without the daphnia.
- Sample storage conditions before analysis: in plastic containers at about 4-5°C

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test substance and the test medium were introduced in 2-liter polypropylene beakers in the respective proportions of 1, 10, 32 and 100 mg per 1000 g. The contents of the beakers were magnetically stirred (60-mm long cylindrical magnetic bar) during 7 days (168 hours) at 20°C in such a manner that the vortex almost produced air in the solution. Evaporation was measured and compensated by double distilled water addition. After 168 hours stirring, the contents of the beakers were filtrated with a sight pressure on Millipore membrane HAWP04700 of 0.45 µm porosity. The solutions obtained were used as the test solutions.
- Differential loading: The 4 loading rates were prepared individually (and not by dilution from a stock solution).
- Controls: Blank (test water without addition of the test item)
- Evidence of undissolved material: No data

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain: IRCHA
- Source: Obtained from the breeding of the laboratory of ecotoxicology of CRIT/D
- Age at study initiation: Less than 24h.
- Weight at study initiation: No data
- Length at study initiation: The daphnids used passed through a sieve of 560 µm mesh, and were retained on a sieve of 315 µm mesh.
- Method of breeding: No data
- Feeding during test: No

ACCLIMATION
- Acclimation period: No

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Test temperature:

Between 19.6°C and 19.9°C

pH:

7.80 to 7.85

Dissolved oxygen:

96 to 100% of saturation

Nominal and measured concentrations:

- Nominal loading rate: 0 - 1 - 10 - 32 and 100 mg/L
- Mesured Cerium concentrations:
* Samples taken during the preparation of the test solution; that is after 6 days (144 hours) of stirring: 0.3 (LOQ) - 2.4 - 3.5 - 3.5 - 9.6 µg/L
* Samples taken at the end of the preparation of the test solution; that is after 7 days (168 hours) of stirring (t = 0): 0.3 (LOQ) - 3.7 - 6 - 3.5 - 16.9 µg/L
* Samples taken after 48 hours of daphnid exposure (t = 48): 2.2 (contamination of the control sample, value not taken into account) - 4.8 - 6.1 - 4.5 - 13.5 µg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 180 mL non-reusable plastic (polypropylene) containers (Before utilisation, the container were soaked in double distilled water during 24 hours).
- Material, size, headspace, fill volume: vessels filled with 80 mL of test solution
- 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
- Renewal rate of test solution: none (static test)
- No. of organisms per vessel: 20
- No. of vessels per concentration: 2
- No. of vessels per control: 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted test water with analytical grade salts dissolved using double distilled water
- Total organic carbon: No data
- Particulate matter: No data
- Metals: No data
- Pesticides: No data
- Chlorine: No data
- Alkalinity: No data
- Ca/mg ratio: No data
- Conductivity: 1.38 µS/cm
- Culture medium different from test medium: No data
- Intervals of water quality measurement: At the start and at the end of the test, the pH values and the dissolved oxygen concentrations were determined at each test concentration and in the control.

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: Exposure was performed in the dark

EFFECT PARAMETERS MEASURED:
The daphnids were observed for immobility after 24 and 48 hours of exposure

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3.2 (100 - 32 - 10 - 1 mg/L nominal loading rates) knowing that a higher factor was used between the two lowest loading rates.
- Justification for using less concentrations than requested by guideline: only 4 laoding rates were tested without justification within the report. As less than 50 % of effect was observed at the highest loading rate, there is no incidence of using only 4 loading rates.
- Range finding study: No

Reference substance (positive control):

yes

Remarks:

(potassium dichromate)

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 other: % saturated aqueous solution

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Key result

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Mortality of control: 0%; thus fulfilling the guideline recommendation of a control mortality <10%
No further detail on results.

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- EC50-24h (Daphnia magna): 1.3 ppm(w/w)
- Acceptance ranges of the laboratory and the OECD guideline: 0.6-1.7mg/L and 0.6-2.1 mg/L, respectively

Reported statistics and error estimates:

No statistics performed because less than 50 % of effect was observed at the highest loading rate.

Any other information on results incl. tables

Physico-chemical parametres and % daphnia immobilization:

Loading Rate (mg/L nominal)	Test container number	Immobilized daphnids number/20		% of immobilized daphnids		% O2	pH
		after 24 hours	after 48 hours	after 24 hours	after 48 hours	after 48 hours	after 48 hours
control	1	0	0	0	0	99	7.8
1	1	0	0	0	0	99	7.85
	2	0	0	0	0	98	7.85
10	1	0	0	0	0	98	7.80
	2	0	0	0	0	99	7.80
32	1	0	0	0	0	96	7.80
	2	0	0	0	0	98	7.80
100	1	1	2	5	10	100	7.85
	2	0	0	0	0	99	7.8

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Dicerium trisulphide is not harmful to aquatic invertebrates up to its solubility limit in the test water at the loading rate of 100 mg/L (48h-EC50 - Daphnia magna > 100 % saturated aqueous solution).

Executive summary:

The 48hr-acute toxicity of dicerium trisulphide to Daphnia magna was studied under static conditions according to the EU Commission Directive 92/69/EEC, Part C.2 (1992). Daphnids were exposed for 48 hours to a control and the test item at nominal loading rates ranging from of 1 to 100 mg/L. Number of immobile organisms were counted after 24 and 48 hours. Immobilized test organisms were only observed at the higher loading rate in only one replicate and didn’t reach the level of 50%, during the test period of 48h. Thus, the 48 hours EL50 was > 100 % saturated aqueous solution. Dicerium trisulphide is not harmful to aquatic invertebrates up to its solubility limit in the test water at the loading rate of 100 mg/L