Registration Dossier

Ecotoxicological information

Sediment toxicity

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Freshwater: chronic toxicity data are available for 7 species. Species mean NOECs used for PNEC derivation range from 201 to 1135 mg/kg dw. The species mean NOEC added range between 146 to 1101 mg/kg dw (after correction for background). In addition, two field studies are available for freshwater sediments. Lieber et al. 1996 have reported an overall NOECecosystem of 725 mg/kg d.w. added zinc. Burton et al. 2005 have observed minor effects on species richness and macroinvertebrate density at concentration of 119 mg/kg d.w. added zinc.
Marine water: chronic toxicity data are available for 2 marine species: the amphipod Melita plumulosa with a NOEC reproduction of 730 mg/kg dw and the mangrove Avicennia marina with a NOEC emergence of 250 mg/kg dw. After background correction the NOEC values then become 490 mg/kg dw and 207.1 mg/kg dw for M. plumulosa and A. marina, respectively. No field studies were found for marine sediments.

Key value for chemical safety assessment

Additional information

Freshwater PNECadd, sediment

The assessment of the freshwaterPNECadd, sedimentfor zinc is based on the chronic benthic toxicity data that were presented in the EU RAR for zinc (2008), complemented with four new high quality studies (species). From the knowledge available at the time of closure, the RAR derived a PNEC using an application factor of 10 on the lowest available NOEC value (488 mg/kg d.w.). Because of the significant increase of information on chronic benthic toxicity, the PNEC from the RAR has been revised. Taking into account the weight of evidence provided by the elements discussed in the chemical safety report, it is considered that use of the HC5 from the SSD, using statistical extrapolation techniques, is justified for PNEC derivation, and that no additional assessment factor needs to be applied. Consequently, the PNEC is set at the level of the HC5 which is considered as protective for EU freshwater ecosystems:freshwaterPNECadd, sediment= 117.8 mg/kg d.w. (equivalent to 25.9 mg/kg w.w.).

Marine PNECadd, sediment

The assessment of the marine PNECadd, sedimentfor zinc identified two long-term chronic toxicity studies. However, an EqP (using partitioning coefficients and a robust aquatic toxicity database) approach provided a reliable derivation for the marine benthic compartment. The resulting value is considered protective for EU marine ecosystems: marine PNECadd, sedimentof 56.5 mg/kg d.w. (equivalent to 12.5 mg/kg w.w.).