*3.2.1.3. Crustacean toxicity test procedure*

The toxicity test determined the metal concentration that immobilizes or kills 50% (LC50) of *D. magna* crustacean, after chemical exposure at 20°C ± 2°C in the dark for 24 or 48 h. The test procedure was performed according to OECD 202 using the microbiotest Daphoxkit F Magna provided by MicroBioTests Inc., Belgium. Briefly, the test was performed in three replicates, in multiwall test plates (six rinsing wells and 24 wells for toxicant dilutions) using 20 organisms per each concentration (at least five different concentrations for each metal) and control (untreated standard freshwater). The mortality/immobility percentage of organisms was registered after 24 and 48 h.
