Alcohols, C18-22, distn. residues

Long-term toxicity to fish

Description of key information

Behenyl Bottoms are characterised as Alcohols, C18-22, distillation residues. The study for long-term toxicity to fish is considered technically not feasible because the water solubility of the substance is well below the limit of quantification. The low solubility of the substance makes it technically unfeasible to undertake a guideline (standard) study of long-term fish ecotoxicity where the test substance would need to be maintained in solution for several weeks (depending on fish species) to be available for uptake by fish.  In addition, according to REACH Annex IX Column 2, the studies required in Annex 9.1.6, are not needed for alcohols with carbon chains >C15 because sufficient information is available to predict no toxicity at their limit of solubility. Therefore, long-term toxicity to fish requirements are waived based on technical testing difficulties due to low solubility and an absence of short-term toxicity to aquatic organisms at the limit of solubility.

Additional information

Behenyl Bottoms are characterised as Alcohols, C18-22, distillation residues. The study for the long-term toxicity to fish 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 fish ecotoxicity where the test substance would need to be maintained in solution for several weeks (depending on fish species) to be available for uptake by fish. Therefore, long-term toxicity to fish requirements are waived based on technical testing difficulties. In addition, according to REACH Annex IX Column 2, the studies required in Annex 9.1.6, are not needed for alcohols with carbon chains >C15 because sufficient information is available to predict no toxicity at their limit of solubility. Therefore, long-term toxicity to fish requirements are waived based on technical testing difficulties due to low solubility and an absence of short-term toxicity to aquatic organisms at the limit of solubility. 

Study technically not feasible

The requirement to conduct long-term fish 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 fish ecotoxicity where the test substance would need to be maintained in solution for several weeks (depending on fish species) to be available for uptake by fish.

Low Toxicity to Aquatic Organisms

Generally the short-term aquatic toxicity of Behenyl Bottoms (Alcohols, C18-22, distillation residues) is low based on experimental evidence presented in this dossier. The short-term toxicity of Behenyl Bottoms to the fathead minnow (Pimephales promelas) was reported by Palmer et al., (2009) in an OECD 203 guideline and GLP compliant study resulting in a 96-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). It is unlikely that the substance would be available for uptake from the aquatic compartment. Therefore, long-term toxicity to fish 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. 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.