Trichloroethylene (TCE) — biological monitoring
When to suspect: Metal degreasing, dry cleaning, adhesives, electronics cleaning, solvent extraction.
Urine trichloroacetic acid (TCA); blood free trichloroethanol (mg/L)
| Level | Interpretation |
|---|---|
| TCA < 1 | Non-exposed background (urine, mg/L) |
| TCA 15 | ACGIH BEI — end of shift at end of workweek |
| Blood TCOH 0.5 | ACGIH BEI — free trichloroethanol, EOS/EOW (mg/L) |
Ns — TCA/TCOH also arise from tetrachloroethylene & 1,1,1-trichloroethane, so a raised result is not specific to TCE. TCE is A2 (suspected carcinogen).
Biological exposure index
ACGIH BEI: urine TCA 15 mg/L; blood free trichloroethanol 0.5 mg/L — both EOS at end of workweek.
Basis: ACGIH BEI (ATSDR ToxProfile Table 8-1; SafeWork Australia).
Sample collection & preparation
- Urine: clean plastic → transport tube. Blood TCOH per lab (GC).
- END OF SHIFT at END OF WORKWEEK (long half-life — accumulates over the week).
- Note co-exposure to other chlorinated solvents (confounds). No fasting/seafood concern.
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