N-hexyllithium

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2010-05-04 to 2010-08-09

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

1310-66-3

EC Number:

603-454-3

Cas Number:

1310-66-3

IUPAC Name:

1310-66-3

Constituent 2

Reference substance name:

Lithium hydroxide monohydrate

IUPAC Name:

Lithium hydroxide monohydrate

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
NA

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

In order to confirm correct dosage and stability of exposure concentrations, samples (about 50 mL) of the control and all test concentrations of the Definitive Test with five test concentrations were taken directly from the test vessels including tap water (controls) or test solutions. AES-analysis was performed after dilution of the samples in deionised water to meet the linear range of the calibration lines.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
For the Range-Finding Test the test solutions were prepared in a dilution series from a stock solution of 100 mg/L of the test item in tap water. For the Definitive Test as Limit Test and the Definitive Test with five test concentrations the test solutions were prepared by direct transfer of weighted samples in various amounts of the test Item into the tap water in the test vessels. The test solutions were prepared using a mixing device (Ultra-Turrax, Janke & Kunkel; 8000 rpm, 2 minutes for the Range-Finding Test; 9500 rpm, 3 minutes for the Definitive Tests). The test solutions showed slight turbidity, followed by a whitish precipitation at test concentrations of 50 and 100 mg/L in the Range-Finding Test and at test concentrations of 50 to 200 mg/L in the Definitive Tests. This precipitation had no effect on the test item concentration. The Range-Finding Test and the Definitive Tests were performed as static tests, i.e. without renewal of the test solutions. The controls were kept in tap water. For concentration analysis samples were taken directly from the test vessels at 0 h and 96 h. The Range-Finding Test and Definitive Tests were performed without adjustment of the pH.

Test organisms

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish
- Strain: Teleostei, Cyprinidae
- Source: Max-Planck-Institut für Entwicklungsbiologie, Tübingen
- Length at study initiation: 2.0 +/- 1.0 cm
- Method of breeding:
- Feeding during test: no feeding during the test

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Test conditions

Test temperature:

21.6 – 22.3 degree C (test water)

pH:

At the beginning of the definitive test: 10.7

Dissolved oxygen:

At the beginning of the definitive test: 96 %

Nominal and measured concentrations:

Nominal test concentration: 100 mg test item/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 20 L solid-glass fish tanks
- Aeration: none


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: fluorescent tubes (14 h light, 10 h dark)

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

109 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

LiOH monohydrate

Basis for effect:

mortality (fish)

Effect concentrations 2

Duration:

96 h

Dose descriptor:

LC10

Effect conc.:

90 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

LiOH monohydrate

Basis for effect:

mortality (fish)

Effect concentrations 3

Duration:

96 h

Dose descriptor:

LOEC

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

LiOH monohydrate

Basis for effect:

mortality (fish)

Effect concentrations 4

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

LiOH monohydrate

Basis for effect:

mortality (fish)

Effect concentrations 5

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

239 mg/L

Nominal / measured:

nominal

Conc. based on:

other: calculated for n-hexyllithium

Basis for effect:

mortality (fish)

Details on results:

Due to the mortality of three of seven fish in the Definitive Test as Limit Test it was decided to perform a Definitive Test with five test concentrations:
- Nominal test concentrations: Control, 12.5 , 25.0, 50.0, 100 and 200 mg test item/L

Observations in the Definitive Test with five test concentrations during 96 h:
- Control: Swarming behaviour and activity were normal during 96 h.
- 12.5 mg/L: Comparable to control during 96 h.
- 25.0 mg/L: Comparable to control during 96 h.
- 50.0 mg/L: Comparable to control during 0 – 72 h. Activity was slightly reduced compared to the control after 96 h and as tendency the fish were found in the lower parts of the test vessel.
- 100 mg/L: Activity was slightly reduced compared to the control during 0 – 72 h and as tendency the fish were found in the lower parts of the test vessel. Activity was reduced after
96 h, the fish were found in the lower parts and at the bottom of the test vessel and also showed balance disorder. Two fish died during 72 – 96 h.
- 200 mg/L: The fish showed strong balance disorder, agitated swimming movements and surfacing immediately after transfer into the test vessel, all seven fish died within 15 minutes.

Reported statistics and error estimates:

Determination of the LC50 (96 h), LC20 (96 h) and the LC10 (96 h) (LC = Lethal Concentration) with reference to mortality of the fish was performed using Probit-analysis (Finney-method, lognormal distribution, confidence limit 95 %, significance level: 0.05).

Any other information on results incl. tables

Sublethal observations / clinical signs:

Definitive Test as Limit Test

Number of dead fish and cumulative mortality [%] at 0 h, 24 h, 48 h, 72 h and 96 h:

Time [h]	Control		100 mg/L *
	Number	[%]	Number	[%]
24	0/7	0	0/7	0
48	0/7	0	0/7	0
72	0/7	0	0/7	0
96	0/7	0	3/7	42.8

* nominal concentration of Lithium hydroxide monohydrate

Definitive-Test with five test concentrations

Number of dead fish and cumulative mortality [%] at 0 h, 24 h, 48 h, 72 h and 96 h:

Time [h]

Control

12.5 mg/L *

25.0 mg/L *

50.0 mg/L *

100 mg/L *

200 mg/L *

Number

[%]

Number

[%]

Number

[%]

Number

[%]

Number

[%]

Number

[%]

24

0/7

0

0/7

0

0/7

0

0/7

0

0/7

0

7/7

100

48

0/7

0

0/7

0

0/7

0

0/7

0

0/7

0

7/7

100

72

0/7

0

0/7

0

0/7

0

0/7

0

0/7

0

7/7

100

96

0/7

0

0/7

0

0/7

0

0/7

0

2/7

28.6

7/7

100

* nominal concentration of Lithium hydroxide monohydrate

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In this 96-h fish acute toxicity test with Zebrafish (Danio rerio) the 96h LC50 for Lithium hydroxide monohydrate based on mortality was determined to be 109 mg/L. Based on read across approach LC50 value calculated for n-Hexyllithium is 239 mg/L.

Executive summary:

The acute toxic effects of Lithium hydroxide monohydrate to Zebrafish (Danio rerio) over a 96 hour static exposure period were assessed according to OECD guideline 203. For the Range-Finding Test the test solutions were prepared in a dilution series from a stock solution of 100 mg/L of the test item in tap water. For the Definitive Test as Limit Test and the Definitive Test with five test concentrations the test solutions were prepared by direct transfer of weighted samples in various amounts of the test Item into the tap water in the test vessels. AES-analysis confirmed that the test solutions were correctly dosed, i.e., the recoveries were within 92.6 to 96.2 % of the nominal concentrations at study start. At the end of the exposure, i.e., after 96 hours, the recoveries ranged from 98.8 to 101 % of the nominal concentrations demonstrating that the lithium concentrations were stable throughout the exposure period. Consequently, the results of the Definitive Test were based on nominal concentrations.

In this 96-h fish acute toxicity test with Zebrafish (Danio rerio) the 96h LC50 for Lithium hydroxide monohydrate based on mortality was determined to be 109 mg/L. Based on these data the calculated LC50 for n-Hexyllithium is 239 mg/L.