The German Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (MAK Commission) derived a concentration in workplace air for chlorinated biphenyls (PCBs) 1336-36-3 which is without risk to the develop- ing foetus (corresponding to Pregnancy Risk Group C). The derivation is based on the prerequisite for the classification in Pregnancy Risk Group C at 3.5 µg/l plasma for the sum of the 6 indicator congeners (6IC) PCB 28, PCB 52, PCB 101, PCB 138, PCB 153 and PCB 180. Assuming a background concentration of 2 µg 6IC/l plasma for women up to 45 years of age with data from about 2010, an increment of 1.5 µg 6IC/l plasma is thus tolerable. This increment was estimated to correspond to a total PCB concentration in air of 0.0008 mg/m3 measured as the sum of the 6IC multiplied by 5. This concentration represents a rather conservative estimate, as the background concentration in plasma has reduced since and a respiratory volume of 10 m3 has been assumed, which might overpredict the exposure at workplaces in PCB-contaminated office or public buildings. Additionally, age and duration of exposure are important determinants for the inner exposure. These factors should be considered when evaluating the measurement results
Hartwig et al. (Mon,) studied this question.