Neodymium trinitrate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

17 March 1997 - 21 March 1997

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

significant methodological deficiencies

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

- a stock solution of approximately 1 % was prepared each day by dissolving the test substance directly into distilled water
- test solutions were prepared by adding proper amounts of stock solution and dilute further with dilution water to obtain the test concentrations
- for the preparation it was taken into account that the substance is an aqueous solution with approximately 55 % of neodymium nitrate

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

- Common name: rainbow trout
- Strain: Walbaum
- Source: fish culture of Roger TEPPE, 01310 Polliat
- Age at study initiation (mean and range, SD): not reported
- Length at study initiation (length definition, mean, range and SD): 4.9 ± 0.7 cm
- Weight at study initiation (mean and range, SD): 1.3 ± 0.7 g
- Method of breeding: not reported
- Feeding during test: no

ACCLIMATION
- Acclimation period: 24 hours prior to start of test, selected fish were kept starved and placed in new aquaria
- Acclimation conditions (same as test or not): yes, same as test

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

110-140 ppm as CaCO3

Test temperature:

Definitive assay: 15.4 ± 1°C
Complementary assay: 15.3 ± 1°C

pH:

Definitive assay: 7.4-8.0
Complementary assay: 7.8-8.2

Dissolved oxygen:

70-78 %

Salinity:

Not applicable.

Nominal and measured concentrations:

Four assays were performed:
- Nominal concentrations during range-finding test: 1 and 10 mg/L
- Nominal concentrations during limit test: 100 mg/L
- Nominal concentrations during definitive test: 0.60, 1.4, 3.0, 6.7, 15 and 32 mg/L
- Nominal concentrations during complementary test: 0.1, 0.27 and 0.6 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: aquarium
- Material, size, headspace, fill volume: glass, 28 cm x 28 cm x 28 cm, headspace not reported, fill volume not reported
- Aeration: not reported
- Renewal rate of test solution (frequency/flow rate): after 24h, 48h and 72h living fish were transferred to fresh aquaria (with test solution or dilution water for the treatment and blanc fish respectively), while dead fish were removed
- No. of organisms per vessel: 5 for the four assays
- No. of vessels per concentration (replicates): 2 for the limit, definitive and complementary assays, 1 for the range-finding assay
- No. of vessels per control (replicates): 2 for the four assays
TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: potable water, stabilised, dechlorinated by aeration
OTHER TEST CONDITIONS
- Adjustment of pH: not reported
- Photoperiod: 12:12 hours dark:light
- Light intensity: 1000 - 2000 lux at water surface
EFFECT PARAMETERS MEASURED (with observation intervals if applicable): mortality after 3 hours and then daily
TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2.13 to 2.7 during the definitive and complementary assays
- Range finding study
- Mortality was observed at the three concentrations tested during the range-finder and limit test (1 mg/L: 0 % mortality, 10 mg/L: 80 %, 100 mg/L: 100 %).

Reference substance (positive control):

yes

Remarks:

lindane

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: C.I.: 1.0-3.7 mg/L

Details on results:

- LC50(24h) = 23 mg/L, 95 % C.I. 15 - 50 mg/L
- LC50(48h) = 5.5 mg/L, 95 % C.I. 3.3 - 10 mg/L
- LC50(72h) = 2.1 mg/L, 95 % C.I. 1.1 - 4.1 mg/L

Results with reference substance (positive control):

- LC50(24h) = 0.048 mg/L, 95 % C.I. 0.041 - 0.056 mg/L

Reported statistics and error estimates:

Probit analysis.

Sublethal observations / clinical signs:

No analytical monitoring was performed to investigate the stability of the test item in the test media. Precipitation of Nd may have occurred; which could have led to an underestimation of the ecotoxicity. Therefore, the results should not be considered entirely reliable. However, as relatively important adverse effects were observed in this study underestimating toxicity, it may be used as supporting study.

Validity criteria fulfilled:

yes

Conclusions:

This study reported an LC50 of 2.0 mg Nd(NO3)3/L for Onchorhynchus mykiss after a 96-h exposure to neodymium nitrate. The results can not be considered entirely reliable as the test concentrations were not analytically verified and as precipitation may have occurred; which could have led to an underestimation of toxicity.

Description of key information

This study reported an LC50 of 2.0 mg Nd(NO3)3/L for Onchorhynchus mykiss after a 96-h exposure to neodymium nitrate. The results can not be considered entirely reliable as the test concentrations were not analytically verified and as precipitation may have occurred; which could have led to an underestimation of toxicity.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

2 mg/L