VOC Biological Monitoring

Solvents & VOCs · Solvents & VOCs overview

VOC biological monitoring quantifies urinary metabolites of volatile organic compounds to verify absorbed dose across both inhalation and dermal routes — the only matrix that does so simultaneously for the most common UK industrial solvents.

Why VOCs require biological verification

Volatile organic compounds typically have skin notation in the HSE EH40 list because lipophilic compounds cross stratum corneum readily. Personal air sampling captures inhalation only, so for VOCs it systematically under-reports total exposure. Urinary metabolites of the parent compound integrate uptake across all routes and across the shift.

VOC biomonitoring is also the most cost-effective verification tool for SEGs of more than five workers: a single shift of collection produces a defensible cohort statistic.

Common VOC biomarkers

Aromatic VOCs are addressed via substance-specific pages: benzene (S-PMA, t,t-muconic acid), toluene (o-cresol), xylenes (methylhippuric acids), styrene (mandelic + phenylglyoxylic acid), ethylbenzene (mandelic acid).

Oxygenated VOCs include butan-2-one (urinary MEK — HSE BMGV 70 µmol/l) and cyclohexanone (urinary cyclohexanediols — HSE BMGV 8 mmol/mol creatinine).

Halogenated VOCs include trichloroethylene (trichloroacetic acid, end-of-week), perchloroethylene (urinary TCA or PER in exhaled air) and methylene chloride (urinary methylene chloride and blood COHb).

Sampling design for VOCs

End-of-shift is the default. For VOCs with overnight half-lives — TCE, PER — pre-shift next morning is the appropriate window. End-of-shift-end-of-week is used where biomarker half-life exceeds 24 hours and weekly cumulative dose is the interpretation question.