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Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Category information on envrionmental fate and pathway of alcohol ethoxylates

Alcohol ethoxylates are readily biodegradable under aerobic conditions and also anaerobically biodegradable (HERA, 2009). The main mechanism of primary biodegradation for the linear and essentially linear AE is the central cleavage of the molecule, leading to the formation of long chain alcohol and polyethylene glycol (HERA, 2009; Marcomini et al., 2000a; Marcomini et al., 2000b). Long chain alcohols themselves are readily biodegradable up to C18 (SIDS, 2006). 

Abiotic degradation in water, soil, sediment and air is not expected to occur because of the chemical structures of AE homologues. Neither hydrolysis under normal environmental conditions (pH range from 4 to 9) nor photolysis in the atmosphere, in water, or when absorbed to soil and sediment surfaces, is to be considered (HERA, 2009).

Experimentally determined BCF-values given for pure homologues and summarized in the publication of Tolls et al. (2000) are used as read-across data for the endpoint bioaccumulation in water. It can be stated that bioaccumulation of alcohol ethoxylates is regarded to be negligible as the surfactants will be rapidly metabolised. For more detail see endpoint summary for bioaccumulation.

Concerning transport and distribution of the alcohol ethoxylate mixtures a high adsorption of the substances is determined by using QSAR-models. Adsorption onto surfaces is an intrinsic property of alcohol ethoxylates and thus a high Koc-value is expected.

More details on the category approach are given in a separate document (see attached IUCLID chapter 13).

Key information for the assessment of alcohol ethoxylate (Z)-9-Octadecen-1-ol ethoxylated, < 2.5 EO, CAS 9004-98-2)

  • Biodegradability: Readily biodegradable; 83.6% (CO2 evolution) in 28 days (OECD 301B)
  • Bioaccumulation potential: Bioaccumulation in organisms is negligible, due to biotransformation and excretion of alcohol ethoxylates.
  • Adsorption potential: Based on the composition of the mixture the weighted average of the Koc values was calculated to be 457467 L/kg. This value is used for the determination of PNECsediment with the equilibrium partitioning method.