Nickel bis(dibutyldithiocarbamate)

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

fish early-life stage toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1985-07-05

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 212 (Fish, Short-term Toxicity Test on Embryo and Sac-Fry Stages)

GLP compliance:

no

Specific details on test material used for the study:

- Name of test item (as cited in study report): Nickeldibutyldithiocarbamate (NiDBC)
- Source: Akzo Chemicals Dordrecht
- Purity: 97%

Analytical monitoring:

not specified

Vehicle:

yes

Remarks:

acetone

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
A stock solution in acetone was made, from which a second stock solution in dilution water was prepared.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish
- Source: The test organisms were obtained from a local aquarium retailer.

METHOD FOR PREPARATION AND COLLECTION OF FERTILIZED EGGS
The test organisms were kept in the laboratory at 24 ± 2 °C, males and females in separate groups. They were bred at regular intervals: in the afternoon females were isolated in small tanks filled with a mesh bottom at 26 ± 2 °. After a few hours two males were introduced before the lights went off. In the morning the lights were turned on, eggs were produced. Each batch of eggs was collected from the bottom of the tank by a small fishing net and transferred to a small volume of water. White and opaque eggs and empty shells were removed and the quality of the batch and their stage of development was assessed. For each test eggs of only one female were used to insure a more homogenous population of test eggs. On several occassions, tests were repeated, enabling to compare the sensitivity of batches of different origin.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

10 d

Hardness:

200 mg CaCO3/L, 13 °dH

Test temperature:

23 - 27 °C

pH:

Approximately 8.2

Nominal and measured concentrations:

- Nominal concentrations: 0 (control), 0.32, 1, 3.2, 10 and 32 mg/L

Details on test conditions:

TEST SYSTEM
Test containers were polystyrene multi-dishes with 6 holes each containing 5 mL of test medium. Five to seven eggs were transferred to each hole by means of a glass tube equiped with a rubber bulb. Incubation started within 4 hours after spawning (gastrula stage). The eggs were incubated at 25 ± 2 °C under artificial light during working hours.

TEST MEDIUM
The dilution water was a synthetic medium, Dutch Standard Water, containing 100 mg NaHCO3/L, 20 mg KHCO3/L, 200 mg CaCl2.2H2O/L and 180 mg MgSO4.7H2O/L. The medium was aerated before use. The medium was renewed after two or three days.

EFFECT PARAMETERS MEASURED
Daily observations were made on survival of eggs and larvae, hatching and malformations. Dead organisms were removed. Oxygen, pH and temperature were measured to confirm that the test conditions were normal.

Key result

Duration:

10 d

Dose descriptor:

NOEC

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

10 d

Dose descriptor:

other: LC100

Effect conc.:

32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

- NOEC hatching: 10 mg/L
- NOEC malformations: 10 mg/L

Table: results early life stage test

Day	0	2	2	3	3	4	4	5	5	6	6	7	7	10	10
Nom. Conc (mg/L)	eggs	eggs	larvae	eggs	larvae	eggs	larvae	eggs	larvae	eggs	larvae	eggs	larvae	eggs	larvae
control	36	17	0	17	0	2	15	0	16^1	0	16^1	0	16^1	0	16 ^1
0.32	34	25	0	22	1	7	16	0	23	0	23	0	23	0	23
1	36	27	0	27	0	4	23 ^3	1	26	1	26	1	26	1	26
3.2	36	22	0	22	0	1	21 ^2	0	22	0	22	0	22	0	22
10	36	23	0	21	2	1 @	22	1 @	22	1 @	22	1 @	22	0	19
32	36	0	0	0	0	0	0	0	0	0	0	0	0	0	0
control	36	28	0	20	8 ^1					0	28	0	28	0	27
5	36	29	0	23	6					1	28	1	28	0	28

@: non-specific malformations

^: slightly bend behind the head

Validity criteria fulfilled:

not specified

Description of key information

The 10-d NOEC value is 10 mg/L in early-life stage zebrafish (Danio rerio).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

10 mg/L

Additional information

The chronic toxicity to fish was determined in a non-GLP study similar to OECD 212. In this study zebrafish embryos (Danio rerio), (~36 per concentration) were exposed to nominal concentrations of 0 (control), 0.32, 1, 3.2, 10 and 32 mg/L prepared in acetone for 10 days under semi-static conditions. The eggs were incubated at 25 ± 2 °C under artificial light during working hours. The media were renewed every 2 -3 days. Five to seven eggs were transferred to a hole containing 5 mL test medium. No analytical confirmation was performed. Daily observations were made on survival of eggs and larvae, hatching and malformations. Dead organisms were removed. Oxygen, pH and temperature were measured to confirm that the test conditions were normal. Hatching success was not affected compared with the negative control up to 10 mg/L. At 32 mg/L, all the eggs malformated and died within two days. In the lower concentration treatments, small malformations were recorded but no significant effects were observed. Based on these results, the 10-d NOEC was determined to be 10 mg/L.