P-368 Pcb, Lead and Toluene – Which Concentration Protects Against Prenatal Toxicity? Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area – Working Group “Assessment Values in Biological Material”

Abstract Introduction The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area derived health-based BAT values for PCB, lead and toluene, not all of which adequately protect the unborn children of pregnant employees. Methods Data from animal experiments and epidemiological studies on developmental toxicity (and neurotoxicity) were used to assess the prenatal toxic effect of the substances and to establish a concentration at which damage to the embryo or foetus is unlikely. Results For PCBs, prenatal toxic effects cannot be ruled out at the BAT value of 15 μg/l plasma (Group B) but a concentration of 3.5 µg/l (NOAEL for developmental neurotoxicity) was derived at which a risk to the unborn child would be unlikely (“prerequisite for Group C”). Even if the BAT value of 150 μg/l blood value is adhered to, prenatal toxic effects have been reliably proven for lead (Group A). For toluene, the NOAECs in animal studies for developmental toxicity or developmental neurotoxicity are 600 and 1200 ppm, respectively. Thus, prenatal toxic effects are unlikely at the BAT value of 600 μg toluene/l blood (Group C). Discussion Hitherto, lead is the only substance in Group A. No NOAEC for the critical effect of developmental neurotoxicity can be derived for lead. Conclusion The assignment of substances to pregnancy risk groups enables pregnant women to work without risk to their unborn children if the substance is classified in Group C or when a concentration is derived at which damage to the embryo or foetus is unlikely.