Neodecanoic acid, neodymium salt

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

other information

Study period:

October 1999 to November 1999

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study follows general OECD/ EC guidances for testing acute toxicity to fish. However, it is not GLP-compliant and no chemical analysis was performed to verify actual concentrations during the test.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Principles of method if other than guideline:

Groups of 10 zebrafish (Danio rerio) were exposed for 96 hours to the test substance at 1, 10 and 100 mg/L and to a control treatment. Behaviour and mortality was assessed daily.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

neodymium(3+) 2-ethyl-2,5-dimethylhexanoic acid tris(2-ethyl-2,5-dimethylhexanoate)

EC Number:

600-768-2

Cas Number:

106726-11-8

Molecular formula:

C30H57NdO6

IUPAC Name:

neodymium(3+) 2-ethyl-2,5-dimethylhexanoic acid tris(2-ethyl-2,5-dimethylhexanoate)

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material (as cited in study report): Neodymium versatate
- Physical state: Blue powder
- Storage condition of test material: Ambient conditions

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Test solutions were prepared approximately 65 hours before the fish introduction by adding the right quantities of test item and water in the test vessels. A dispersion of the test item was obtained through homogeneization using ultra-turrax T45/6. Then, test solutions were stirred for approximately 65 hours at 22°C using a magnetic bar.
- Differential loading: Three loading rates were tested; being 1, 10 and 100 mg/L.
- Controls: A test vessel containing only dilution water was prepared in the same conditions.
- Evidence of undissolved material (e.g. precipitate, surface film, etc): At the end of the stirring period and for all the tested concentrations, blue cristals of the test item were observed at the bottom of the test vessels.

Test organisms

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish
- Source: HB DEVELOPPEMENT (rearing facilities of La Grande Rivière, 69490 - SAINT-FORGEUX)
- Length (measured at the end of the assay): 3.02 +/- 0.24 cm
- Weight (measured at the end of the assay): 0.34 +/- 0.10 g
- Feeding during test: No, for 24 hours prior to the test start, test fish were kept starved in a different vessel.

ACCLIMATION
- Acclimation period: Yes, but duration not available.
- Acclimation conditions: The water used for the fish acclimation was tap water dechlorinated by aeration (same water as for the test solution preparation).

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test conditions

Hardness:

130 mg/L as CaCO3

Test temperature:

No data on the water temperature, but the assay was performed in a dedicated room with a temperature regulated at 22 +/- 1°C.

pH:

Measured at the end of the assay (i.e. after 96h), in the control vessel and the vessels exposed to the test item:
7.85 to 7.95

Dissolved oxygen:

Start (t = 0): 100 %
t = 24h: 82 to 87 % before aeration, 96 % after aeration
t = 48h: 89 to 91 % before aeration, 98 % after aeration
t = 72h: 91 to 93 % before aeration, 98 % after aeration
End (t = 96h): 85 to 88 %

Nominal and measured concentrations:

Nominal loading rates: 1, 10 and 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass aquaria (28 x 28 x 28 cm).
- Aeration: yes, just before the fish introduction and at 24, 48, 72 hours, test and control solutions were aerated for 30 minutes.
- No. of organisms per vessel: 10 fish.
- No. of vessels per concentration (replicates): 1 vessel.
- No. of vessels per control (replicates): 1 vessel.
No further data.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: tap water dechlorinated by aeration.
- Hardness: 130 mg/L as CaCO3
- pH: 8.3
- Dissolved oxygen: 100 % of air saturation at 22 °C.
- Intervals of water quality measurement: pH was measured at the end of the assay (after 96h). Dissolved oxygen concentration was measured just before the fish introduction, before and after aeration at 24, 48, 72 hours and at the end of the test (after 96 hours).
No further data.

OTHER TEST CONDITIONS
- Adjustment of pH: No.
- Photoperiod: 12 hours light, 12 hours dark.
- Light intensity: 1000 to 2000 lux at the water surface.

EFFECT PARAMETERS MEASURED
Behaviour and mortality were assessed after 3, 24, 48, 72 and 96 hours.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 10
No further data.

Reference substance (positive control):

yes

Remarks:

Lindane

Results and discussion

Effect concentrations

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: No abnormal behaviour was observed in the fish exposed to the test item and the control.
- Mortality: No mortality was observed in the fish exposed to the test item and the control.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: At the end of the stirring period and for all the tested concentrations, blue cristals of the test item were observed at the bottom of the test vessels.

Results with reference substance (positive control):

- Results with reference substance valid? Yes, results are consistent with those already obtained with this substance (lindane) within the testing laboratory.
- 24h-LC50 = 0.14 mg/L
- Other: Additional details on reference substance:
* Name: Lindane (Hexachloro -1,2,3,4,5,6 γ cyclohexane)
* Source: MERCK
* Batch number: 9267229

Reported statistics and error estimates:

No statistics were performed as no adverse effect was observed at the highest loading rate tested.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

Control mortality: 0 % (threshold =< 10%), dissolved oxygen concentrations: 82-100% (threshold >= 60%)

Conclusions:

Neodecanoic acid, neodymium(3+) salt (3:1) has no acute adverse effect on fish (Brachydanio rerio) up to and including the loading rate of 100 mg/L.

Executive summary:

The acute toxicity to fish of Neodecanoic acid, neodymium(3+) salt (3:1) was investigated by exposing groups of 10 zebrafish (Danio rerio) for 96 hours to the test substance at 1, 10 and 100 mg/L and to a control treatment. Behaviour and mortality were assessed after 3 hours and then daily. Neither abnormal behaviour, nor mortality was observed in the fish exposed to the test item and the control. The 96h-LL50 is thus > 100 mg/L; meaning that Neodecanoic acid, neodymium(3+) salt (3:1) is not hamful to fish.