Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

ErC20 (72h) = 1.027 mg/L for Desmodesmus subspicatus (QSAR estimation)

Key value for chemical safety assessment

Additional information

Since only a few data on the long-term aquatic toxicity for the mixtures within the category are available, the assessment on long-term toxicity is based on alcohol ethoxylate specific QSARs (Wind & Belanger, 2006; Boeije et al., 2006; Belanger et al, 2006). The QSARs considered all three trophic levels (algae, invertebrates and fish). The effects are described as EC20 values, since the QSARs are more robust for the EC20 values than for NOEC or EC10 values. For the described mixture (C12 -13, <2.5 EO, CAS 66455-14-9) the QSAR for long-term toxicity on green algae Desmodesmus subspicatus (Wind & Belanger, 2006) result in an EC20-value of 0.373 mg/L based on biomass and 1.027 mg/L based on growth rate, respectively. This result (ErC20 = 1.027 mg/L) was used as key value for the further assessment.

Additionally two GLP-studies for algae (Pseudokirchneriella subspicata) in static systems are available for alcohol ethoxylates C12 -13 with different degrees of ethoxylation. In the study of Hoberg (Shell, 1996) conducted according to EPA OTS 797.1050 with alcohol ethoxylates of a chain length of C12 - C13 and a degree of ethoxylation of 4.5 - 6, an EC50 (cell density) of 0.22 mg/L (purity of test material: 100%) was determined. In the study of Thompson & Swigert (Shell, 1995) conducted according to OECD 201 on an alcohol ethoxylate mixture of C12 - C13 with EO5 an EC50 -values for cell density of 0.26 mg/L (Thomspon & Swigert, 1995) is reported.

In addition a study conducted with the linear and branched C12 -C13 mixture is available which is also conducted according to OECD 201 under GLP-conditions. In this study an EC50 of 0.282 mg/L based on growth rate is reported. This study is conducted with CAS 160901-19-9 representing another category member.