In 2010, the U.S. Environmental Protection Agency (EPA) announced its intention to propose a rule to reduce mercury waste produced by dental offices. The agency intends to focus its technology assessment on amalgam separators and is preparing a regulatory proposal for review. Amalgam separators are devices designed to capture amalgam particles from dental office wastewater before it is discharged into the public sewer system.

This laboratory evaluation shows that amalgam separators and the filtration devices removed at least 97.05 percent of the amalgam in samples with particle-size distribution as specified in ISO Standard 11143.

This laboratory evaluation shows that amalgam separators removed at least 96.09 percent of the amalgam in samples with particle-size distribution as specified in ISO 11143. Total mercury concentration and total dissolved mercury concentration in the effluent varied widely for each amalgam separator. Additional research is needed to develop test methods to evaluate the efficiency of amalgam separators in removing small amalgam particles, colloidal amalgam particles and ionic mercury in solution.