Feldspar minerals, hematite and quartz, calcination products of copper mining residues

Toxicity to aquatic algae and cyanobacteria

Description of key information

In accordance with column 2 of REACH Annex VII, studies on toxicity to algae do not need to be conducted on iron oxides, as the category members are inert inorganic oxides of iron, manganese and zinc and highly insoluble in water. Soluble salts of these metals are already present in algal growth and test media as essential nutrients at concentrations exceeding the solubility of iron in the iron oxides. Additionally, studies are presented with read across from soluble iron substances. For LEAD: For algae, 7 individual reliable freshwater acute toxicity data points for one species were put forward for hazard assessment purposes. The acute toxicity values (48h-LC50) for Pseudokirchneriella subcapitata varied between of 21.7 µg dissolved Pb/L (at pH 7.5 and hardness of 24.2 mg/L) and 322.9 µg dissolved Pb/L (at pH 7.3 and hardness of 174.4 mg/L). 2 different chronic high quality no-effect levels for dissolved lead for freshwater algae situated between 34.1µg Pb/L and 93.0 µg Pb/L (Pseudokirchneriella subcapitata) were observed. High quality no-effect levels for dissolved lead for marine algae plants were situated between 52.9 µg Pb/L (Skeletonema costatum; endpoint: yield) and 1231.8 µg Pb/L (Dunaliella tertiolecta; endpoint: growth rate).