Lithium chloride

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 daphnia with lithium carbonate is not available. Consequently, read-across was applied using study results obtained from supporting substances, lithium metal and lithium hydroxide monohydrate.

Both studies were performed under semi-static conditions according to OECD guideline 211. The adjustement of pH was onyl performed in the study with lithium metal. The results of both studies are summarised below:

Substance	Species	NOEC (mg/L)	NOEC Li+ (mg/L)	Exposure time	Study type	Reference
Li metal	Daphnia magna (water flea)	1.7	1.7	21 days	OECD 211 (semi-static)	TOXI-COOP, 2012
LiOH monohydrate	Daphnia magna (water flea)	4	0.7	21 days	OECD 211 (semi-static)	Steinbeis, 2010

 

The long term test with LiOH monohydrate resulted in  an effect concentration below 1 mg Li+/L. It can be assumed that the unadjusted and strong alkaline pH increased the toxicity noted in the study after long-term exposure. Thus, a pH effect cannot be excluded for this study even if not seen in 24h pre-test.

Therefore the study using Li metal and pH adjustment resulting in a NOEC of 1.7 mg/L is considered as more reliable and used to calculate the respective value for lithium carbonate.

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

 

Toxicity to aquatic algae and cyanobacteria

A toxicity study on algae with lithium carbonate is available. Furthermore read-across was applied using characteristically similar compounds. Three guideline and GLP compliant studies are available for the salts lithium hydroxide, lithium chloride and lithium carbonate. All three studies were performed under static conditions according to OECD guideline 201 in Pseudokirchneriella subcapitata (LiOH monohydrate, with pH adjustment) and Desmodesmus subspicatus (LiCl, Li2CO3 without pH adjustment).

The effect concentrations are summarized below.

Substance	Species	EC50/NOEC (mg/L)	EC50/NOEC Li+ (mg/L)	Exposure time	Study type	Reference
LiOH monohydrate	Pseudokirchneriella subcapitata (green algae)	153/10	25/2	72 h	OECD 201 (static)	TOXI-COOP, 2010
LiCl	Desmodesmus subspicatus	400/25	65/4	72 h	OECD 201 (static)	Steinbeis, 2010
Li2CO3	Desmodesmus subspicatus	400/50	75/9	72 h	OECD 201 (static)	Steinbeis, 2010

 

The highest toxicity was noted in Pseudokirchneriella subcapitata with LiOH. As the pH was adjusted, pH effects can be excluded. The two other salts were tested in Desmodesmus subspicatus revealing significantly lower toxicity.

This indicates a different susceptibility of the two algae species used in the three tests towards Li. As the pH adjustment for LiOH monohydrate was performed with HCl, the toxic effects noted reflect most likely the toxicity of the Li ion. It can further be concluded that the substance in the experimental part of this study is rather LiCl instead of LiOH. When comparing both the study with LiOH monohydrate (at least partially being equivalent to LiCl) and LiCl it can be assumed that Pseudokirchneriella subcapitata (green algae) are more sensitive towards lithium than Desmodesmus subspicatus. This explains the higher EC50 and NOEC values in test with this species for LiCl and Li2CO3.

As a consequence, the EC50 and NOEC values for Li+ obtained in Pseudokirchneriella subcapitata are taken as starting figures to derive the respective values for lithium carbonate.

Based on read-across approach, the calculated EC50 and NOEC for lithium carbonate are 135 and 9 mg/L, respectively.

 

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).