On April 1, 2026, the European Chemicals Agency (ECHA) released a scientific assessment report on occupational exposure limits (OELs) for three key lithium compounds (lithium carbonate, lithium chloride, and lithium hydroxide) and initiated a two-month public consultation on the related recommendations.
Scope of the Assessment
This assessment covers three lithium compounds classified for reproductive toxicity:
- Lithium carbonate (EC No.: 209-062-5; CAS No.: 554-13-2)
- Lithium chloride (EC No.: 231-212-3; CAS No.: 7447-41-8)
- Lithium hydroxide (EC No.: 215-183-4; CAS No.: 1310-65-2)
Proposed Occupational Exposure Limits
|
Limit Type |
Value |
Basis |
|
8-hour TWA (fertility, animal data) |
0.46 mg Li/m³ |
Based on animal reproductive toxicity |
|
8-hour TWA (developmental toxicity, human data) |
11.3 mg Li/m³ |
Based on human developmental effects |
|
8-hour TWA (developmental toxicity, animal data) |
0.35 mg Li/m³ |
Based on animal developmental toxicity |
|
8-hour TWA (kidney effects, human data) |
0.75 mg Li/m³ |
Based on human kidney data |
|
8-hour TWA (kidney/liver effects, animal data) |
0.13 mg Li/m³ |
Based on animal kidney/liver toxicity |
|
Short-term Exposure Limit (STEL) |
0.02 mg Li/m³ |
Only for lithium hydroxide (corrosivity) |
|
Biological Limit Value (BLV) |
Not recommended |
— |
|
Skin/Respiratory Sensitization Notation |
None |
No evidence to support |
Key Recommendations
ECHA recommends that the Risk Assessment Committee (RAC) consider the following when establishing final OELs:
- Choose between human data (developmental toxicity, 11.3 mg/m³) and animal data (kidney/liver toxicity, 0.13 mg/m³)
- Consider the specific corrosivity of lithium hydroxide and propose a short-term exposure limit of 0.02 mg/m³
- Not recommend a skin notation, as dermal absorption is negligible
- Not recommend a biological limit value, as multiple biological monitoring reference values are already available
Public Consultation and Follow-up Procedures
ECHA launched the public consultation on April 1, 2026. Stakeholders may submit comments on the scientific report by June 1, 2026. Following the consultation, ECHA's Risk Assessment Committee (RAC) will integrate scientific evidence and public feedback to formulate a formal opinion on occupational exposure limits, providing a basis for the European Commission to establish binding limits.
