Lithium carbonate

Endpoint summary

Additional information

Short-term toxicity to fish

A static freshwater toxicity test was conducted to determine the acute toxicity of lithium carbonate to rainbow trout, Oncorhynchus mykiss according to OECD Guideline No. 203. Mean measured concentration of lithium carbonate ranged from 4.99 to 77.7 mg wm/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 wm/L to 100 % at 77.7 mg wm/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. (FMC, 1996)

Based on these data, the calculated LC50 for lithium ion was 5.69 mg/L and the NOEC was 3.59 mg/L.

Long-term toxicity to fish

A long-term toxicity test in fish with lithium carbonate is not available. Consequently, read-across was applied using results obtained from lithium hydroxide monohydrate, as the lithium ion is considered as the relevant toxic species and not the naturally occuring counter ions ( (Cl-, CO3^2-).

The purpose of the performed study was to evaluate the chronic toxicity of the test item lithium hydroxide monohydrate to early life stages (embryo, larvae and juveniles) of fish (Danio rerio) according to the OECD 210 guideline. Around 40 eggs per treatment / concentration level (2 replicates per treatment) were exposed in a semi-static test to aqueous test media containing the test item for 34 days at a range of concentrations (based on a preliminary study) under defined conditions. Results showed that lithium hydroxide monohydrate had significant lethal effect on early life stages of Zebrafish (Danio rerio) at a concentration level of 24.35 mg/L (measured concentration). The observed effect was associated with larval/juvenile stages, but no significant effect was observed during the embryonic stage. No significant sub lethal effects (hatching of the larvae, body weight, body length, deformities and abnormal behaviour) were observed in any concentration tested.

The following endpoints (34 days LOEC and NOEC) were determined in the study:

LOEC of 24.35 mg LiOH monohydrate/L

NOEC of 17.35 mg LiOH monohydrate/L (Toxicoop, 2012)

Based on read-across approach, the calculated LOEC and NOEC values for lithium carbonate were 21.44 and 15.28 mg/L, respectively.

The NOEC result does not lead to classification and labelling of lithium carbonate for long-term aquatic toxicity (fish) according to Regulation (EC) No 1272/2008 (CLP) and Directive 67/548/EC (DSD).

Short-term toxicity to aquatic invertebrates

A static freshwater toxicity test was conducted to determine the acute toxicity of lithium carbonate to the water flea, Daphnia magna according to OECD Guideline 202. Mean measured concentrations of lithium carbonate ranged from 4.76 to 82.8 mg/L and from 95 to 109 % of nominal. All test solutions appeared clear and colourless and concentrations remained stable throughout the test. Mortality of the water flea exposed for 48 hours to lithium carbonate ranged from 0 % at test concentrations lower than 20.0 mg/L to 100 % at 82.8 mg/L. Control mortality was 0 %.

The 48-hour EC50 was 33.2 mg lithium carbonate/L with 95 % confidence limits of 20.0 and 43.7 mg/L.

The NOEC was 20.0 mg lithium carbonate/L, based on a lack of significant mortality and sublethal effects observed at this and all lower test concentrations. (Toxikon, 1997)

Based on these data, the calculated EC50 for lithium ion was 6.24 mg/L and the NOEC was 3.76 mg/L.

Long-term to aquatic invertebrates

Long-term toxicity test in aquatic invertebrates with lithium carbonate is not available. Consequently, read-across was applied using study results obtained from lithium.

The purpose of this study was to evaluate the influence of the test item lithium on the reproductive output of Daphnia magna in a semi-static test system according to OECD Guideline 211. Young female Daphnia (the parent animals) aged less than 24 hours at the start of the test were exposed to aqueous test media containing the test item for 21 days at a range of concentrations. The nominal test item concentrations were 0.50, 0.75, 1.13, 1.70, 2.53, 3.80 and 5.70 mg lithium/L. The performed parallel running analytical determinations confirmed that the test item concentrations examined (lowest and highest test concentrations) remained within the range of ± 20 % of the nominal and of the initial concentrations (varied between 98 and 117 per cent of the nominal concentration); thus, all results were based on the nominal test item concentrations. In the three highest tested concentrations (2.53, 3.80 and 5.70 mg/L) all parent animals died by the 13th day of the test without producing any offspring. Therefore the results of these concentrations were excluded from the data analysis related to the reproductive output. In the control group two parent animals (20 %) died during the test which was within the acceptable validity criteria. In the concentration range of 0.50 – 1.70 mg/L mortality of parent animals was not observed during the experiment. The reproduction was not reduced statistically significantly in the concentration range of 0.50 – 1.70 mg/L compared to the untreated control group. During the evaluation of the body length of parent animals at the end of the test, statistically significant difference was not observed in the remained living parent daphnids (in the concentration range of 0.50 – 1.70 mg/L) compared to the control group. Aborted broods, presence of male neonates or ephippia were not noticed during the test. Accordingly, the 21-day NOEC value related to reproduction was determined to be 1.70 mg/L and the LOEC value as 2.53 mg/L. The obtained results were not sufficient for an exact EC50 value estimation. The 21-day EC50 was determined to be higher than 1.70 mg/L. (Toxicoop, 2012)

Based on a read-across approach, the calculated NOEC value for lithium carbonate was 9 mg/L.

Toxicity to aquatic algae and cyanobacteria

The effect of lithium carbonate on the growth of an algal species Desmodesmus subspicatus over a 72 hour static exposure period was assessed according to OECD guideline 201. The test solutions were prepared in a dilution series from a stock solution of 100 mg/L of the test item in culture medium for the range-finding test and from a stock solution of 400 mg/L of the test item in culture medium for the definitive test, respectively. The stock solutions and the corresponding dilutions were prepared using a mixing device (Ultra-Turrax, Janke & Kunkel; 8000 rpm, 2 minutes). The test solutions were clear at all test concentrations. The controls were kept in culture medium. Vessels including culture medium (controls) and test solutions were kept under the same conditions as the test vessels for concentration analysis. Concentration analysis was performed at 0 h and 72 h. The Alga-test was carried without adjustment of the pH. AES-analysis confirmed that the test solutions were correctly dosed, i.e., the recoveries were within 92.4 to 103 % of the nominal concentrations at study start. At the end of the exposure, i.e., after 72 hours, the recoveries ranged from 95.9 to 103 % 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 72-h algal growth inhibition test with Desmodesmus subspicatus the 72-h EC50 based on growth rate was determined as greater than 400 mg/L for lithium carbonate. (Steinbeis, 2010)

The overall NOEC was determined to be 50 mg/L for lithium carbonate (the calculated NOEC for lithium ion: 9.39 mg/L) . The results are based on the nominal concentrations.

Toxicity to microorganisms

A microorganism toxicity test with lithium carbonate is not available. Consequently, read-across was applied using study results obtained from lithium hydroxide.

The influence of the test item lithium hydroxide on the activity of activated sludge by measuring the respiration rate was evaluated according to OECD Guideline 209 and EU method C.11. The respiration rate (oxygen consumption) of an aerobic activated sludge fed with a standard amount of synthetic sewage was measured in the presence of various concentrations of the test item after an incubation period of 3 hours. The inhibitory effect of the test item at the particular concentrations was expressed as percentage of the mean respiration rate of two controls. Following test concentrations were used: 10, 32, 100, 320 and 1000 mg lithium hydroxide/L; 3.2, 10 and 32 mg 3,5 -dichlorophenol/L and two inoculum controls. In comparison to the inoculum controls the respiration rate of the activated sludge was inhibited between –1.8% and 98.2 % up to the highest nominal test concentration of 1000 mg/L. Concentrations exceeding 1000 mg/L nominal were not tested. The 3-hour EC 50 for the positive control 3,5 -dichlorophenol, which was tested in the same way as the test item, was found to be 7.5 mg/L and is within the range of 5 – 30 mg/L recommended by the test guidelines; thus, confirming suitability of the activated sludge. The 3 hours EC20, EC50, and EC80 values for the test substance lithium hydroxide in the activated sludge respiration inhibition test were 114.3, 180.8, and 286.1 mg/L (based on measured inhibition rates), respectively. The EC10 value was calculated be linear regression to be 79.2 mg/L. (LAB, 2004)

Based on this data 3 hours EC10, EC20, EC50, and EC80 values can be calculated for lithium carbonate as 122.2, 176.3, 278, and 441.4 mg/L, respectively (calculated EC10 for lithium ion: 22.95 mg/L).