Chromium (VI) — biological monitoring
When to suspect: Electroplating (chrome), stainless-steel welding, leather tanning, pigments, wood preservation.
Total chromium in urine (µg/L)
| Level | Interpretation |
|---|---|
| < 1 | Non-exposed background |
| +10 during shift | ACGIH BEI — increase pre- to post-shift |
| 25 (EOS/EOW) | ACGIH BEI — end of shift at end of workweek |
Ns — total urine Cr reflects total absorbed chromium (any valence), not Cr VI specifically. Cr VI = A1 carcinogen; BEI is a monitoring guide, not a "safe" level.
Biological exposure index
ACGIH BEI (water-soluble Cr VI fume): +10 µg/L during shift; 25 µg/L EOS/EOW (ACGIH µg/L, not creatinine-adjusted).
Basis: ACGIH BEI (Mayo Clinic Labs interpretive data).
Sample collection & preparation
- Acid-washed / trace-element-free plastic, no metal cap; transfer without utensils.
- Paired PRE-shift and END-of-shift on the last day of the workweek.
- Remove work clothing + wash hands before voiding (airborne Cr dust contamination). No fasting.
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