Investigating the Safety of Trace Element Products for Biogas Plants Using Biological Tests
In July 2024, the Technical Rule for Hazardous Substances 529 (TRGS 529) was revised. TRGS 529 applies to all activities related to the production of biogas as well as the operation of biogas plants. It also regulates the handling of additives and auxiliary materials, including special safety measures required when using cobalt and nickel, as both heavy metals are considered carcinogenic. This applies not only to the use of cobalt and nickel salts but also to their complex compounds.
The new development is that additives and auxiliary materials such as cobalt and nickel can now be used without special safety measures, provided that biological tests have demonstrated that the mechanisms relevant to cancer development are not activated. In accordance with this regulation, researchers at Fraunhofer ITEM have developed human-relevant biological tests for the complex compounds of the heavy metals cobalt and nickel to provide this evidence. The researchers were able to show that, under physiological conditions, the heavy metal ions are not bioavailable in humans and therefore do not exhibit any relevant toxic effects. In principle, this testing strategy can also be applied to similar questions and other trace elements.
Microorganisms require cobalt and nickel to optimally ferment plants or manure in biogas plants. These trace elements are typically not used in animal feed or agriculture and therefore must be added. Compounds of these metals are classified as carcinogenic, which requires special occupational safety measures. Additionally, according to legal requirements, hazardous additives must be replaced by less hazardous substances or work processes in line with the TRGS. These rules are developed by the Committee for Hazardous Substances (AGS) on behalf of the Ministry of Labor and Social Affairs (BMAS) and are published in the Joint Ministerial Gazette. The Technical Rules for Hazardous Substances (TRGS) of the Federal Institute for Occupational Safety and Health (BAuA) apply in Germany and are based on EU directives and international standards to ensure workplace safety.