Objectives: Ten amalgam separators were tested using ISO Standard 11143. Methods: 10 g of amalgam particles conforming to the particle size distribution in the ISO Standard were introduced with 1L of water into the amalgam separator along with additional water to reach manufacturer's specified flow rate. The effluent from the amalgam separator was collected and filtered through pre-weighed filters (12 µm, 3 µm, 1.2 µm). The filters, with the retained amalgam particles, were dried to constant weight. Amalgam separator efficiency was calculated from the amount of amalgam retained on the filters. We also determined the concentration of mercury from intentionally digested amalgam in the filtrate (1.2 µm filter and 0.45 µm filter) using chemical analysis. Results: The amalgam separator efficiencies are: Amalgam Collector 99.89 (0.06%), Asdex 99.10 (0.09%), BullfroHg 98.88 (0.64%), Durr 7800 97.66 (0.35%), ECO II 97.51 (0.74%), Hg 5 98.28 (0.10%), MRU 99.95 (0.04%), MSS 2000 98.94 (0.06%), Rasch 890-4000 99.90 (0.03%), RME 2000 99.66 (0.24%). ANOVA and Tukey tests showed no difference (p<0.05) among MRU, Rasch 890-4000, Amalgam Collector, RME 2000, Hg 5 and Asdex or among Hg 5, Asdex, MSS 2000, and BullfroHg. Durr 7800 and ECO II are different from all other separators. The t-test on the efficiency of each separator tested "empty" and "full" showed no significant difference (á=0.05) except for MSS 2000. Mercury concentrations in the chemically digested amalgam effluent filtrate ranged from 1 ppb to >7000 ppb and varied extensively for each separator. Conclusions: Ten amalgam separators tested exceeded the ISO requirement of 95% amalgam removal. Chemically digested amalgam effluents from separators have mercury levels in the ppb range.