Fluoride (HF / fluoride dust) — biological monitoring
When to suspect: Aluminium smelting (pot rooms), HF / hydrofluoric handling, glass etching, phosphate fertiliser, welding flux.
Urinary fluoride (mg/g creatinine)
| Level | Interpretation |
|---|---|
| 2 (pre-shift) | ACGIH BEI — prior to shift (reflects body burden) |
| 3 (end-of-shift) | ACGIH BEI — end of shift (current exposure) |
Collect PAIRED pre- and end-of-shift spot samples. (Older NIOSH figures 3 / 10 superseded by ACGIH 2 / 3.)
Biological exposure index
ACGIH BEI: urine fluoride 2 mg/g creatinine (pre-shift) and 3 mg/g creatinine (end-of-shift).
Basis: ACGIH BEI; NIOSH 8308 (collection).
Sample collection & preparation
- Chemically clean polyethylene bottle; NIOSH 8308 adds ~0.2 g EDTA preservative per bottle (prevents fluoride loss).
- Paired PRE-shift + END-of-shift spot samples; creatinine-corrected.
- Note dietary fluoride (tea, fluoridated water, seafood, swallowed toothpaste) which raises background.
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