Strategy of biological monitoring and setting of biological threshold limits (BAT values) in Germany.

Biological monitoring is of fundamental importance in Germany. The successful strategy of biological monitoring is based on four factors. Recommendations for the pre-analytical phase have been issued by official societies. For the analyses in blood and urine specimens around 100 methods have been recommended and standardized. All measurements must be carried out under a quality control scheme issued by the German Ministry of Labor and organized by the German Society of Occupational and Environmental Medicine. The occupational medical judgement of the biological monitoring results take place by "Biological Tolerance Values for Working Materials" (BAT values) and "Exposure Equivalents for Carcinogenic Working Materials" (EKA values). A BAT value is, by definition, the maximum allowable concentration for an individual which should be exceeded; 53 BAT values for 37 agents or groups of agents and 18 EKA values for 10 compounds have been defined. These values have been published since 1982 in an annual list of occupational standards. Every BAT or EKA value is based on extensive scientific documentation.