Registration Dossier

Diss Factsheets

Administrative data

Link to relevant study record(s)

Description of key information

Key value for chemical safety assessment

Additional information

Six healthy male volunteers were exposed for 8 h to DMBA at air levels of 20, 45, and 80 µm/m³. Air levels of DMBA were analyzed by gas chromatography (GC). The total urinary amount of DMBA (U-SumDMBA; DMBA and metabolites that can be reduced to DMBA, e.g., N,N-Dimethylbenzylamin-N-oxide) was analyzed using GC-mass spectrometry (MS). The exposure chamber maintained very low (0 -130 µg/m³) and steady concentrations for several weeks. DMBA uptake by inhalation was 76%. The amine was quickly distributed and biotransformed to nearly 100%. DMBA was eliminated in the urine with a half-time of 4.3 h. More than 50% was eliminated within 2 h of exposure (Stahlbom, 1997).

The detection limit for DMBA in air for a 60-l air sample collected in 10 ml absorption solution was 2 µg/m³ and in charcoal tubes, 0.3 µg/m³. The detection limit for DMBA in urine was 0.02 mg/l. Ten male workers manufacturing epoxy resin were monitored during a full shift in the working environment and urine samples were collected at the end of exposure. The mean exposure and the highest DMBA concentration observed in air were 18 µg/m³ (time-weighted average: range 3 - 48 µg/m³) and 91 µg/m³, respectively. The DMBA concentrations in the urine samples were below the detection limit. After reduction of the urine samples the DMBA concentrations (U-SumDMBA) ranged from 0.02 to 0.22 mg/l. There was significant correlation between the exposure to DMBA and the U-SumDMBA. This observation suggests that the U-SumDMBA in urine samples collected at the end of a shift is a useful indicator of occupational exposure to DMBA (Stahlbom, 1995).