Alcohols, C18-22, distn. residues

Toxicity to terrestrial arthropods

Description of key information

Behenyl Bottoms are characterised as Alcohols, C18-22, distillation residues. The REACH requirement in Annex IX for studies on soil arthropods is waived on the basis of direct or indirect exposure of the soil compartment being unlikely.

Additional information

Behenyl Bottoms is characterized as Alcohols, C18-22, distillation residues and the requirement for testing is waived. The REACH requirement in Annexes IX and X for studies on terrestrial organisms can be waived if direct or indirect exposure of the soil compartment is unlikely. In particular, substances that are unlikely to be persistent in the environment do not require long-term terrestrial testing.

Terrestrial testing is waived based on the unlikely direct or indirect exposure to soils, lack of persistence in the environment, the low toxicity in aquatic organisms and the low toxicity in mammals resulting in the unlikely direct or indirect exposure of terrestrial organisms to the test substance, as presented in more detail below:

Exposure to soils

It is unlikely that soil organisms will be exposed to the test substance as there is no intended use involving the direct application of Behenyl Bottoms to soil.

Persistence

Results of the ready biodegradability tests with Behenyl Bottoms demonstrate that it is inherently biodegradable in fresh water (Schaefer & Matthews, 2010). The test substance biodegraded to an extent of 84.1% after 60 days and can be regarded as inherently biodegradable. According to ECHA Guidance, when the half-life is greater than 40 days in freshwater, the substance is considered to be persistent. Based on an average of three replicates and the steady rate of biodegradation, it can be assumed that the half-life of the substance is below the persistence (P) criterion when 50.3% of the substance biodegraded in a freshwater environment by day 37 of the test (Schaefer & Matthews, 2010). In accordance with ECHA Guidance (Chapter R.11, PBT Assessment), Behenyl Bottoms does not fulfil the PBT or vPvB criteria for Persistence (P) in the environment and builds on the evidence that the substance is unlikely to persist in the environment for uptake by soil organisms.

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 invertebrates and fish was reported by Palmer et al., (2009) in OECD guideline and GLP compliant studies resulting in LC50s 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 based on the low solubility and the absence of ecotoxicological evidence from experimental studies presented in this dossier. It is reasonable to assume that similarly low toxicities would be seen in terrestrial organisms.

Toxicity to Mammals

There is no requirement in REACH to conduct a secondary poisoning assessment in view of the lack of toxic effects in mammals. Evidence presented in this dossier demonstrates the low toxicity to mammals, for example, Kuhn (2009) reported LD50 in rats to be >2,000 mg/kg and in a reproduction study by Szucs (2010) a NOEL of 1,000 mg/kg/day in rats was reported. Additional evidence in the OECD SIDS report (2006) of long chain alcohols reported low toxicity in chronic and sub-chronic mammalian toxicity studies. Using these combined experimental and published evidence it is assumed that the test substance is not considered to be toxic (in PBT terms) to mammals and secondary poisoning is unlikely to occur in the environment.

In summary, the data requirement for terrestrial studies is waived on the evidence of unlikely exposure to soils and the absence of toxicity in aquatic organisms and mammals.