Alcohols, C18-22, distn. residues

Long-term toxicity to aquatic invertebrates

Description of key information

Behenyl Bottoms are characterised as Alcohols, C18-22, distillation residues. The study for the long-term toxicity to aquatic invertebrates is considered technically not feasible because the water solubility of the substance is well below the limit of quantification based on experimental evidence by Cartee and Schaefer (2009). The low solubility of the substance makes it technically unfeasible to undertake a guideline (standard) study of long-term aquatic invertebrate ecotoxicity where the test substance would need to be maintained in solution for 21 days to be available for uptake by aquatic invertebrates. Therefore, long-term toxicity to invertebrate requirements are waived based on technical testing difficulties due to low solubility.

Additional information

Behenyl Bottoms are characterised as Alcohols, C18-22, distillation residues. The study for the long-term toxicity to aquatic invertebrates is considered technically not feasible because the water solubility of the substance is well below the limit of quantification based on experimental evidence by Cartee and Schaefer (2009). The low solubility of the substance makes it technically unfeasible to undertake a guideline (standard) study of long-term aquatic invertebrate ecotoxicity where the test substance would need to be maintained in solution for 21 days to be available for uptake by aquatic invertebrates. Therefore, long-term toxicity to invertebrate requirements are waived based on technical testing difficulties due to low solubility. In addition, the short-term toxicity of Behenyl Bottoms to Daphnia magna was reported by Palmer et al., (2009) in an OECD 202 guideline and GLP compliant study to be EC50 of >100 mg/L. This reliable study result is designated as key for the short-term toxicity to invertebrates endpoint. Furthermore, long-term toxicity is considered to be below the limit of solubility (LoS) for alcohols > C15 in chain length based on evidence presented in the Long Chain Alcohols SIDS report (2006). In addition, predicted long-term toxicity (ChV) for fish by EPISuite (V4.11) using two representative components (docosan-1-ol and 2-decyltetradecanol) of Behenyl Bottoms indicates that no effects at saturation are expected for this endpoint. It is unlikely that the substance would be available for uptake from the aquatic compartment. Therefore, long-term toxicity to invertebrate requirements are waived based on technical testing difficulties due to low solubility of the test substance and the absence of short-term toxicity to aquatic organisms at the limit of solubility.

Study not technically feasible

The requirement to conduct long-term invertebrate studies for Alcohols, C18-22, distillation residues is waived due to the technical difficulties in performing such a test. The water solubility of the substance is below the limit of quantification based on experimental evidence by Cartee and Schaefer (2009) where the limit of solubility was <1 mg/L. Further evidence provided in this dossier suggests that the maximum solubility for Alcohols, C18-22, distillation residues will be 0.007 mg/L, based on a conservative approach. Predicted water solubility by EPISuite (V4.11) using two representative components (docosan-1-ol and 2-decyltetradecanol) of Behenyl Bottoms indicates that the water solubility ranged from 1.7e-5 mg/L to 1.5e-4 mg/L. The low solubility of the substance makes it technically unfeasible to undertake a guideline (standard) study of long-term invertebrate ecotoxicity where the test substance would need to be maintained in solution for three weeks to be available for uptake by the invertebrates.

Toxicity to Aquatic Organisms

Generally the short-term aquatic toxicity of Behenyl Bottoms (Alcohol, C18-C22, distillation residues) is low based on experimental evidence presented in this dossier. The short-term toxicity of Behenyl Bottoms to Daphnia magna was reported by Palmer (2009) in an OECD 203 guideline and GLP compliant study resulting in a 48-hr LC50 of >100 mg/L. In addition, long-term toxicity is considered to be below the limit of solubility (LoS) for alcohols > C15 in chain length based on evidence presented in the Long Chain Alcohols SIDS report (2006). Predicted long-term toxicity (ChV) for fish by EPISuite (V4.11) using two representative components (docosan-1-ol and 2-decyltetradecanol) of Behenyl Bottoms indicates that no effects at saturation are expected for this endpoint. Therefore, long-term toxicity to invertebrates requirement is waived based on technical testing difficulties due to low solubility of the test substance and the absence of short-term toxicity to aquatic organisms at the limit of solubility.