A series of environmental bioassays and fate studies have been performed on brass dust. The standardized aquatic microcosm (SAM) was used as the long term, ecosystem assay.

Short-term bioassays using Daphna magna and green algae were conducted. The 48-h EC₅₀ of the brass dust to D. magna ranged from 0.016 to 0.026 mg/L. Microscopic investigations indicated that the daphnia filter and ingest the material. Green algae were not as affected by the brass dust as the daphnids. The 96-h IC₅₀ for Ankistrodesmus falcatus is 0.316 mg/L and for Selenastrum capricornutum, 0.056 mg/L. At very low concentrations of the brass, algal growth was stimulated.

Fate studies indicate that brass disassociation in water varies with pH. At low pHs the material rapidly disassociates into Cu⁺⁺ and Zn⁺⁺ ions. At pHs above neutrality the disassociation is markedly slower.

The short-term bioassays and fate studies were used to set the concentrations of brass for the SAM (the SAM is standardized protocol containing algae, invertebrates, bacteria, and a protozoan inoculated in 3 L of medium). A study using CuSO₄ served as a positive control for the brass microcosm. In both microcosms the concentration of available copper slowly decreased until an equilibrium was reached. In addition, both microcosms demonstrated a dose response relationship with an increase in algal biomass correlated with an increase in toxicant dose. The cause is likely to be the elimination of the primary grazers, daphnia, because of the test chemical's toxicity. Recovery as measured by positive population growth of the daphids also demonstrated a dose-response relationship.