Lithium carbonate

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:

key study

Study period:

1996-08-14 to 1996-12-6

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OTS 797.1400 (Fish Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples were analyzed for lithium in triplicate using a FLM-AAS method developed and validated by the FMC Corporation. Measured concentrations of lithium carbonate were calculated by multiplying measured lithium concentrations by 5.3240.

Vehicle:

no

Details on test solutions:

A primary stock solution (5001 mg/L) was prepared by adding 5.0007 g of neat test substance to a 1 L volumetric flask, bringing it to volume with deionized water and sonicating for approximately 50 minutes to ensure homogeneity. Test solutions were prepared by adding appropriate amounts of the primary stock to 9 L volumes of dilution water. A dilution water control was maintained concurrently with the solutions.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

Rainbow trout used for the test ranged from 34 to 49 mm standard length (mean and standard deviation = 40 +/- 4.4 mm) and from 0.42 to 1.46 g wet weight (mean and standard deviation = 0.77 +/- 0.28 g) as measured from the control fish at test termination. Loading was calculated to be 0.86 g of fish tissue per liter of test solution.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

No

Hardness:

c(CaCO3)= 74 mg/L

Test temperature:

11.0 - 12.5 °C

pH:

The pH of the test solutions was affected by the presence of lithium carbonate (i.e., the pH increased as the test substance concentrations increased). The pH values of all test solutions ranged from 8.7 to 10.4 at test initiation and from 6.7 to 9.8 for the remainder of the test.

Dissolved oxygen:

11.7 - 12.2 mg/L (> 100 % of saturation)

Nominal and measured concentrations:

Nominal concentrations: 5.0, 10, 20, 40, and 80 mg/L
Measured concentrations: 0.0, 4.99, 10.0, 19.1, 38.9 and 77.7 mg/L

Details on test conditions:

A 96 -hour static range-finding test was conducted at nominal concentrations of 0.10, 1.00, 10.0, 100, and 1000 mg/L, prior to performing the definitive test. Three fish were tested at each concentration. After 96 hours of exposure, mortality of rainbow trout in the range-finding test was 0 % at the test concentrations 0.10, 1.00, and 10.0 mg/L, and 100 % at 100 and 1000 mg/L. Mortality in the control was 0 %. Undissolved compound was observed at 100 mg/L during the range-finding test. Based upon these results, nominal test concentrations of 5.0, 10, 20, 40, and 80 mg/L were selected for the definitive test.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

30.3 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks:

Li2CO3

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL: 19.1 and 38.9 mg wm/L

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

19.1 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks:

Li2CO3

Basis for effect:

mortality (fish)

Details on results:

The 96-hour LC50 was 30.3 mg/L (based upon mean measured concentrations) with 95 % confidence limits of 19.1 and 38.9 mg/L. The no-observed-effect-concentration (NOEC) was 19.1 mg/L based on the lack of significant mortality and the absence of sublethal effects at this and lower test concentrations.

Reported statistics and error estimates:

The LC50 values were estimated by a computer program using the following statistical methods: moving average angle, probit, logit, and non-linear interpolation. Confidence limits for LC50 values determined by non-linear interpolation were calculated by binomial probability. The method selected for reporting the test results was determined by the characteristics of the data, i.e. the presence or absence of 0 % and 100 % mortality and the number of concentrations in which mortalities between 0 and 100 % occurred.

Sublethal observations / clinical signs:

Mortality of Rainbow Trout, Oncorhynchus mykiss, during a 96 -hour static exposure to lithium carbonate:

Mean Measured Concentration (mg/L)	Cumulative Number Dead (Percent Mortality)
	24 Hour		48 Hour		72 Hour		96 Hour
Control	0	(0)	0	(0)	0	(0)	0	(0)
4.99	0	(0)	0	(0)	0	(0)	0	(0)
10.0	0	(0)	0	(0)	0	(0)	0	(0)
19.1	0	(0)	0	(0)	0	(0)	0	(0)
38.9	0^a	(0)	5	(25)	15	(75)	17	(85)
77.7	8^b	(40)	19	(95)	20	(100)	20	(100)

a Two fish exhibited dark coloration.

b Five fish exhibited dark coloration.

 

Calculated LC50 values, based upon measured concentrations for Rainbow Trout, Oncorhynchus mykiss, exposed to lithium carbonate under static test conditions:

Exposure Period (Hour)	LC50Value^a	LCL^b	UCL^c	Slope	Method Used
24	>77.7	-	-	-	-
48	47.6	40.5	56.4	7.81	Probit
72	32.1	19.1	38.9	N/A	Binomial
96	30.3	19.1	38.9	N/A	Binomial

a LC50 values and confidence limits expressed in mg wm/L

b Lower 95 percent confidence limit

c Upper 95 percent confidence limit

Validity criteria fulfilled:

yes

Conclusions:

The 96-hour LC50 was 30.3 mg lithium carbonate/L (based upon mean measured concentrations) with 95 % confidence limits of 19.1 and 38.9 mg/L. The NOEC was 19.1 mg lithium carbonate/L based on the lack of significant mortality at this and lower test concentrations.

Executive summary:

A static freshwater toxicity test was conducted to determine the acute toxicity of lithium carbonate to rainbow trout, Oncorhynchus mykiss according to OECD Guideline 203. Mean measured concentration of lithium carbonate ranged from 4.99 to 77.7 mg /L and from 96 to 100 % of nominal. All test solutions appeared clear and colourless and concentrations remained stable throughout the test. The pH of the test solutions was affected by the presence of lithium carbonate (i.e. the pH increased as the test substance concentrations increased). The pH values of all test solutions ranged from 8.7 to 10.4 at test initiation and from 6.7 to 9.8 for the remainder of the test. Mortality of the rainbow trout exposed for 96 hours to lithium carbonate ranged from 0 % at test concentrations <= 19.1 mg /L to 100 % at 77.7 mg /L. No mortality occurred in the dilution water control. The 96-hour LC50 was 30.3 mg lithium carbonate/L with 95 % confidence limits of 19.1 and 38.9 mg/L. The NOEC of 19.1 mg lithium carbonate/L was based on a lack of significant mortality and the absence of sublethal effects at this and all lower test concentrations. Based on these data, the calculated LC50 for lithium ion was 5.69 mg/L and the NOEC was 3.59 mg/L.

Description of key information

The 96-hour LC50 was 30.3 mg lithium carbonate/L (based upon mean measured concentrations) with 95 % confidence limits of 19.1 and 38.9 mg/L. The NOEC was 19.1 mg lithium carbonate/L based on the lack of significant mortality at this and lower test concentrations.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

30.3 mg/L

Additional information

A static freshwater toxicity test was conducted to determine the acute toxicity of lithium carbonate to rainbow trout, Oncorhynchus mykiss according to OECD Guideline 203. Mean measured concentration of lithium carbonate ranged from 4.99 to 77.7 mg /L and from 96 to 100 % of nominal. All test solutions appeared clear and colourless and concentrations remained stable throughout the test. The pH of the test solutions was affected by the presence of lithium carbonate (i.e. the pH increased as the test substance concentrations increased). The pH values of all test solutions ranged from 8.7 to 10.4 at test initiation and from 6.7 to 9.8 for the remainder of the test. Mortality of the rainbow trout exposed for 96 hours to lithium carbonate ranged from 0 % at test concentrations <= 19.1 mg /L to 100 % at 77.7 mg /L. No mortality occurred in the dilution water control. The 96-hour LC50 was 30.3 mg lithium carbonate/L with 95 % confidence limits of 19.1 and 38.9 mg/L. The NOEC of 19.1 mg lithium carbonate/L was based on a lack of significant mortality and the absence of sublethal effects at this and all lower test concentrations. Based on these data, the calculated LC50 for lithium ion was 5.69 mg/L and the NOEC was 3.59 mg/L.