The reported investigations on the uptake of carbon disulphide (CS2) and the excretion of its metabolite 2-thiothiazolidine-4-carboxylic acid (TTCA) were based on results from 403 personal air samples (352 passive and 51 active samples) and 362 TTCA determinations in biological material measured during a field study on the adverse effects due to CS2 exposure. The external exposure ranged from below the detection limit (0.2 ppm) to 66 ppm and the urinary TTCA excretion from below the detection limit (0.16 mg./l) to 33.4 mg/l. The excretion of TTCA in postshift urine related to creatinine and volume showed a linear correlation to the CS2 air concentration. On the basis of these results the influence on the internal exposure of physical work load, dermal exposure and individual parameters (age, Brocaindex, disturbed skin barrier) was evaluated. Correlations between the TTCA values in the postshift urine and the individually measured CS2 concentrations were carried out separately for individual departments and persons with and without indications of a disturbed skin barrier. In order to be able to judge the individual internal exposure related to external exposure, a personal quotient was formed from the TTCA level in the urine and the CS2 air concentration measured on the same day (relative internal exposure RIE index = TTCA mg/g creatinine/CS2 in ppm). On investigating interindividual differences, higher relative internal exposures were found in persons with a heavy physical work load and more intensive skin contact. It could be shown for a large group of persons exposed to CS2 that a pathological skin condition leads to an increase in the dermal penetration rate of hazardous substances.(ABSTRACT TRUNCATED AT 250 WORDS)