Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

A testing proposal is submitted to assess the biodegradation of farnesane in sediment, if the very persistent criteria is met, further testing is proposed to assess the bioaccumulation potential.

Additional information

Farnesane is insoluble in water (0.25 µg/L) and is not expected to hydrolyse. It is not readily biodegradable under the strict conditions of OECD TG 301B. There are non-GLP studies in the peer reviewed literature showing degradation potential in sea-water and soil. In addition, modelled data (EpiSiuite v 4.11, BIOWIN v4.10 and BioHCWin v1.01), predict that farnesane will not be readily biodegradable, that it will be ultimately biodegradable in a period of weeks to months with a half-life of 22 days.

A preliminary study was conducted as part of a standard OECD TG 222 Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei) study to assess the bioaccumulation potential in earthworms. The concentration of the test substance in earthworm tissue following 28 days exposure was 33.7 mg/kg fresh weight (equates to approximately 224 mg/kg dw under the assumption that dry weight is 15 % of fresh weight). The measured test substance concentration following 28 days in soil was 441 mg/g dw (55 % of the nominal 750 mg/kg dw soil). The ratio between the dry weight concentration in earthworm tissue and soil (BCF) is 0.5.

The modelled adsorption potential of farnesane (log Koc) is 6.5 L/kg. Level III fugacity model (LEVEL3NT.exe) predicts that farnesane will partition primarily to water (63.9%), sediment (28%) with small amounts to air (6.9% ) and soil (1.27%).