Registration Dossier

Ecotoxicological information

Sediment toxicity

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

No long-term toxicity effects to sediment organisms are to be expected.

Key value for chemical safety assessment

Additional information

No long-term toxicity test with sediment organisms is available for Fatty acids, C18-unsaturated, trimers (CAS No. 68937-90-6).

However, one short-term study investing the toxicity of Fatty acids, C18-unsaturated, trimers (CAS No. 68937-90-6) to marine sediment organisms (Corophium sp.) is available. In this study, conducted in accordance to OSPAR, Protocols on Methods for the Testing of Chemicals Used in the Offshore Oil Industry, over 10 days in natural sediment no effects were observed at 6095 mg/kg dry sediment and a LC50 of > 12187 mg/kg dry sediment was determined (Staniland, 2005). Based on the lack of effects within the range of water solubility in short-term and long-term toxicity tests with fish for Fatty acids, C18-unsaturated, dimers, hydrogenated (CAS No. 68783-41-5) and the low toxicity to Corophium sp., long-term effects in sediment organisms are also not expected.

Additionally, as Fatty acids, C18-unsaturated, trimers (CAS No. 68937-90-6) has a very low water solubility (< 0.37 mg/L) exposure to the aquatic environment is expected to be extremely low, if at all. Due the adsorption potential of the substance (log Koc is > 5), adsorption to organic carbon in soils and sediments can be expected. Nevertheless, the substance will be mostly eliminated in the sewage treatment plant (STP) as adsorption is likely to occur to the sludge and hence the effluent, which is subsequently discharged from the STP to the rivers should, if at all, have insignificant or negligible quantities of the test substance.

Thus, due to the very low water solubility of Fatty acids, C18-unsaturated, trimers (CAS No. 68937-90-6) sediments are not expected to be the compartment of highest exposure. However if exposure does occur, based on the lack of effects within the range of water solubility in the short-term tests for all members of sub-category 2, the long-term toxicity test with fish for Fatty acids, C18-unsaturated, dimers, hydrogenated (CAS No. 68783-41-5), and the low toxicity to Corophium sp. long-term effects in sediment organisms are not expected.

Thus, a long-term study with sediment organisms is not required.