Lithium — biological monitoring
When to suspect: Lithium metal, lithium salts, Li-ion battery manufacturing / recycling, lithium grease, ceramics, glass.
Serum Lithium (mEq/L)
| Level | Interpretation |
|---|---|
| < 0.6 | Normal (non-exposed population) |
| 0.6 – 1.2 | Therapeutic range (psychiatric patients) |
| 1.5 – 2.0 | Mild toxicity |
| 2.0 – 2.5 | Moderate toxicity |
| > 2.5 | Severe / life-threatening |
In occupational exposure, even sub-therapeutic levels warrant clinical correlation if symptomatic.
Biological exposure index
ACGIH has no formally established BEI for lithium. Urine lithium can be used as a biomonitoring tool — typically sampled end-of-shift.
Basis: Clinical toxicology (serum lithium bands). No ACGIH BEI.
Sample collection & preparation
- Serum (red / gold-top vacutainer).
- Draw ~12 h after last estimated exposure for a trough-equivalent level.
- Repeat at 24–48 h if acute exposure is suspected (redistribution effect).
Statutory basis. Factories Act 1948 sets only AIR limits (Second Schedule TWA/STEL, s.41F) and mandates the hazardous-process exam (s.41C, ≤12-monthly); it gives NO blood/urine values. The ranges below are ACGIH BEI / OSHA / clinical benchmarks (India has not adopted biological limits into law).
Reference information for occupational-health professionals — not medical advice, and not a substitute for examination by a qualified physician.
All 27 agents — toxicology & biological monitoring
MedFactory — Occupational Health Centre software for Indian factories