Lithium

Endpoint summary

Description of key information

1. In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII section 8.5 and in line with animal welfare, an acute toxicity study by oral route does not need to be conducted as lithium is classified as corrosive to the skin according to Regulation (EC) No 1272/2008 CLP (Cat. 1B, H314) and according to Directive 67/548/EEC (R34). Additionally, performance of an acute oral study can be waived under REACH (Annex XI)  as exposure can be excluded because of applied RMM due to substance properties (corrosive, flammable in contact with water)   2. In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII section 8.5 and in line with animal welfare, an acute toxicity study by inhalation route does not need to be conducted as lithium obtain hygroscopic properties that cause burnes, it is known to be corrosive and is classified as corrosive to the skin according to Regulation (EC) No 1272/2008 CLP (Cat. 1B, H314) and according to Directive 67/548/EEC (R34). Further the calculated vapour pressure of 3.49E-29 Pa  at 25 °C (EPIWIN) is very low  therefore lithium has a very low potential to be inhaled.  3. In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII section 8.5 an acute toxicity study by dermal route does not need to be conducted as lithium is known to obtain hygroscopic and corrosive properties and is therefore classified as corrosive to the skin according to Regulation (EC) No 1272/2008 CLP (Cat. 1B, H314) and according to Directive 67/548/EEC (R34). Additionally, the physiochemical and toxicological properties of lithium ion suggest no potential for a significant rate of absorption through the skin and no acute toxicity dermal hazard was evident from an acute toxicity dermal study with lithium carbonate.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Additional information

Acute toxicity oral

 

In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII section 8.5 and in line with animal welfare, an acute toxicity study by oral route does not need to be conducted as lithium is classified as corrosive to the skin (Cat. 1B, H314 according to regulation (EC) No 1272/2008 CLP and R34 according to Directive 67/548/EEC).

 

Lithium must be handled in controlled dry air or maintained under a solvent like mineral oil, avoiding its reactivity with air moisture, otherwise, in contact with moisture air or in contact with water (e.g body fluids) corrosive LiOH and flammable hydrogen are formed. Consequently, lithium is classified and labelled as corrosive, reactive with water and (thereby) flammable (H260, R14 /15). Thus, risk management measures (RMM) are applied preventing direct contact of lithium with the human body and therefore exposure can be excluded. Thus, in any case exposure will be very limited and can be excluded. This provides another reason for waiving of testing under REACH (Annex XI) based on non-exposure. Additionally, the substance handling procedures as indicated above do not technically allow performance of a toxicological study.

 

In conclusion, for regulatory purposes (registration, C&L) performance of an oral acute toxicity study with lithium (or other toxicological endpoints) is neither required (very limited exposure) nor technically feasible or in line with animal welfare due to the substance properties (corrosive, flammable in contact with water).

 

 

Acute toxicity inhalation

 

In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII section 8.5 and in line with animal welfare, an acute toxicity study by inhalation route does not need to be conducted as lithium is classified as corrosive to the skin according to Regulation (EC) No 1272/2008 CLP (Cat. 1B, H314) and according to Directive 67/548/EEC (R34) and its hygroscopic properties cause burns. Further the calculated vapour pressure is 3.49E-29 Pa (EPIWIN), i.e. lithium has a very low potential to be inhaled.

 

 

Acute toxicity dermal

 

In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII section 8.5.3 an acute dermal toxicity study does not need to be conducted if the available information indicats that the substance is corrosive. Lithium is known and classified as corrosive therefore a dermal acute toxicity study with lithium would probably not generate meaningful values because of local tissue damage due to corrosiveness. Additionally, for animal welfare reasons no such study should be performed.

However, the acute toxicity dermal effects of Li+ could be examined in a study performed with lithium carbonate using non-corrosive solutions. A LD50 value of > 2000 mg/kg bw was determined in the study (FMC study, No.I93-1799, 1994-04-01), implying negligible skin penetration of Li+ and no acute toxicity dermal hazard. The study is summarised in the following: "The toxic effects of Lithium carbonate in Sprague-Dawley rats were investigated according to OECD Guideline 402 and EU method B.3 on acute dermal toxicity. Ten Sprague-Dawley rats (5 males and 5 females) were treated with Lithium Carbonate Pharmaceutical Grade (Typical Wt% = 99.7; Guaranteed Wt% = 99) at a dosage level of 2000 mg/kg. The test material was in contact with the intact skin for 24 hours under an occlusive wrap. Observations for toxicity were conducted at 0.5, 1, 2, 3, 4 and 6 hours on the day of dosing and twice daily thereafter for 13 days; on day 14 they were conducted once. A description of local irritation was recorded on day 1, 3, 7 and 14. Body weights were recorded on days 0, 7 and 14 of the study. A gross necropsy was performed on all animals. There were no deaths. All rats remained healthy and gained weight by day 14 of the study. No irritations was noted on any of the test sites. All animals appeared normal at necropsy. Under the conditions of this study, the LD50 is grater than 2000 mg/kg in male and female rats when topically applied."

Therefore, lithium carbonate has not to be classified regarding acute toxicity after dermal exposure according to Directive 67/548/EEC (DSD) and Regulation (EC) No 1272/2008 (CLP).

Based on the above mentioned considerations and in a read-across approach, lithium as well should not to be classified with respect to acute dermal toxicity according to Directive 67/548/EC (DSD) and Regulation (EC) No 1272/2008 (CLP).

Justification for selection of acute toxicity – oral endpoint
In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII section 8.5 and in line with animal welfare, an acute toxicity study by oral route does not need to be conducted as lithium is classified as corrosive to the skin according to Regulation (EC) No 1272/2008 CLP (Cat. 1B, H314) and according to Directive 67/548/EEC (R34). Additionally, performance of an acute oral study can be waived under REACH (Annex XI) based on non-exposure as exposure can be excluded because of applied RMM due to substance properties (corrosive, flammable in contact with water).

Justification for selection of acute toxicity – inhalation endpoint
In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII section 8.5 and in line with animal welfare, an acute toxicity study by inhalation route does not need to be conducted as lithium obtains hygroscopic properties that cause burnes, it is known to be corrosive and is classified as corrosive to the skin according to Regulation (EC) No 1272/2008 CLP (Cat. 1B, H314) and according to Directive 67/548/EEC (R34). Further the calculated vapour pressure of 3.49E-29 Pa at 25 °C (EPIWIN) is very low therefore lithium has a very low potential to be inhaled.

Justification for selection of acute toxicity – dermal endpoint
In accordance with column 2 of REACH Regulation 1907/2006/EC Annex VII section 8.5 an acute toxicity study by dermal route does not need to be conducted as lithium is known to obtain hygroscopic and corrosive properties and is therefore classified as corrosive to the skin according to Regulation (EC) No 1272/2008 CLP (Cat. 1B, H314) and according to Directive 67/548/EEC (R34). Additionally, the physiochemical and toxicological properties of lithium ion suggest no potential for a significant rate of absorption through the skin and no acute toxicity dermal hazard as was evident from an acute toxicity dermal study with lithium carbonate.

Justification for classification or non-classification

Classification, Labelling, and Packaging Regulation (EC) No 1272/2008
The available experimental test data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. Based on available data on acute toxicity, the test item is not classified according to Regulation (EC) No 1272/2008 (CLP), as amended for the tenth time in Regulation (EU) No 2017/776.