Gadoliniumsulfite trihydrate

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Gadoliniumsulfite trihydrate

EC Number:

456-900-2

EC Name:

Gadoliniumsulfite trihydrate

Cas Number:

51285-81-5

Molecular formula:

Gd2(SO3)3*3H2O

IUPAC Name:

digadolinium(3+) trihydrate trisulfite

Test material form:

solid: particulate/powder

Details on test material:

Off white, crystalline powder
Batch number FSG 3896 or 02-FW-095

Sampling and analysis

Analytical monitoring:

yes

Remarks:

ICP-OES with external calibration

Details on sampling:

Directly after preparation in the Iabaratory the test media were given to analysis with the following nominal concentration: 25 mg/L, 35 mg/L, 50 mg/L, 71 mg/L and 100 mg/L. Further samples were analysed 24 and 48 hours after start of the experimental part. They were stored under the same conditions as the vessels with daphnia magna.

Test solutions

Details on test solutions:

The testmedium (reconstituted water and test material) was freshly prepared. Therefore, the calibrated flask with testmaterial and vehicle, reconstituted water, was treated in an ultrasonic device for 1 hour. Subsequently the preparation was stirred with a magnetic stirrer for further 23 hours. After 24 hours the formulation was given through a nutsch filter (pore size > 10 - <16 µm) and a single use syringe filter (pore size 0.2 µm). The filtrate was used for the study.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

The strain with the parent generation was bred and maintained in vessels containing Daphnia magna of different groups. Preparing a new study, juvenile Daphnia magna were separated and placed in 60 ml of reconstituted water. The water was renewed and the Daphnia magna were fed with a suspension of fresh water algae once a week. Newborn animals were separated and allocated to the different dose groups.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Hardness:

about 14° dH

Test temperature:

21 - 22 °C

pH:

7.9 ± 0.3

Dissolved oxygen:

93 - 95 %

Conductivity:

Macro nutrients (mg/L):
CaCl2 · 2H2O 293.8
MgSO4 · 7H2O 123.3
NaHCO3 64.8
KCI 5.8
Na2SiO3 · 9H2O 10
NaNO3 0.27
KH2PO4 0.14
K2HPO4 0.18

Nominal and measured concentrations:

Nominal concentration [mg/L]: 0, 25, 35, 50, 71, 100.
Measured concentration: In all dose groups analysis were performed at different time points. The analytically determined values werein the range of 1.85 %- 2.01% ofthe nominal values. The analytical determined test material concentration at the end could be maintained at >= 80% oft he initial concentration (see Addendum Analysis). For the nominal concentration of 100 mg/L a calculated geometric mean exposure concentration of 1. 91 was determined.

Details on test conditions:

The Daphnia magna were kept in reconstituted water in glass vessels. The study was located in an air-conditioned room in the Institute ofToxicology. Lighting was controlled by a timer to provide a 16 hours light - 8 hours dark regime. Temperature and humidity in the experimental room were measured using a thermohygrograph. At the start of the experimental phase 5 Daphnia magna were placed in each test vessel (25 ml, all-glass) containing 10 ml reconstituted water with or without test material. The vessels were open. The Daphnia magna were not fed, and the test medium was not aerated during the test.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Highest dose tested. No effects were observed.

Effect concentrations 2

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 1.91 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

other: Highest dose tested. No effects were observed.

Effect concentrations 3

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Highest dose tested. No effects were observed.

Effect concentrations 4

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 1.91 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

other: Highest dose tested. No effects were observed.

Effect concentrations 5

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Highest dose tested. No effects were observed.

Effect concentrations 6

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

> 1.91 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

other: Highest dose tested. No effects were observed.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

An aqueous solution of nominal 100 mg/L of Gadoliniumsulfite trihydrate ( = 1. 91 mg/L analytically) revealed no aquatic toxicity in the test system. The 48 hour EC50 to Daphnia magna exceeded the maximal solubility of the test material in reconstituted water and, thus, could not be determined in this test.

Executive summary:

The objective of this study was to determine the acute toxicity of Gadoliniumsulfite trihydrat in an open static test using Daphnia magna. For this purpose, juvenile Daphnia magna were exposed to an aqueous test material solution over 48 hours, under defined conditions. The study comprised of four vessels per concentration containing five Daphnia magna each, i.e., 20 Daphnia per concentration (test medium group). In a pretest with 100 mg/L some Daphnia magna were immobilized. Therefore in the main study test material concentrations of nominal 25, 35, 50, 71, and 100 mg/L were used. Besides the fact that in all test material groups some of the daphnae were trapped at the water surface, the Daphnia magna exposed to aqueous preparations of concentrations of nominal 25, 3 5, 50, 71, and 100 mg/L Gadoliniumsulfite trihydrate were not affected. Even in the high dose group with 100 mg/L revealed no toxic effects. Analytical controls were carried out. The test media concentrations were determined at the start of the experimental part, after 24 and 48 hours. In all dose groups the recovered values werein the range of 1.85%-2.01% ofthe nominal values. For the nominal concentration of 100 mg/L a calculated geometric mean exposure concentration of 1. 91 mg/L was determined. For Gadoliniumsulfite trihydrate the following EC50 values and no effect concentration for Daphnia magna were determined:

Nominal (mg/L) Analytical (mg/L)

24 hour EC50               > 100                     > 1.91

48 hour EC50               > 100                     > 1.91

NOEC                         > 100                      > 1.91

An aqueous solution of nominal 100 mg/L of Gadoliniumsulfite trihydrate ( = 1. 91 mg/L analytically) revealed no aquatic toxicity in the test system. The 48 hour EC50 to Daphnia magna exceeded the maximal solubility of the test material in reconstituted water and, thus, could not be determined in this test.