2-Mercaptobenzothiazole (2-MBT, CAS No. 149-30-4) is mainly used as a vulcanization accelerator in the production of rubber. Other applications are as a fungicide in paints and varnishs and for the external treatment of animals. Because of its manifold application in consumer products, for example in soothers, exposure of the general population to 2-MBT can't be excluded. For the purpose of a toxicological evaluation of a possible body burden, the German HBM-commission derived HBM-I values for 2-MBT in the urine of children and adults. The no observed adverse effect level of 94 mg/kg bw/d from a subchronic oral study with mice was used as the point of departure. After considering a total assessment factor of 350, a tolerable daily intake of 0.3 mg/kg bw/d was deduced for humans. Considering further the percentage of 2-MBT and its glucuronide excreted in urine together with the body weight proportional urine volume leads to an HBM-I value for 2-MBT of 4.5 mg/l urine for children and 7 mg/l urine for adults.