Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 500-016-2 | CAS number: 9004-98-2 1 - 2.5 moles ethoxylated
The risk assessment (PNEC-derivation) using species sensitivity distribution (SSD) method is based on the assumption of a larger dataset of endpoints for aquatic organisms. These values were summarized by Belanger et al. (2006) and the HERA-report (2009). Belanger et al. (2006) listed the chronic ecotoxicity of alcohol ethoxylates for 17 aquatic species conducted in 60 tests. Chronic tests used for HC5-calculation of Belanger et al. (2006) were conducted with invertebrates of different taxa, like crustaceans (Daphnia magna and Ceriodaphnia dubia), insects (Chironomus tentans), molluscs (the bivalvia species Corbicula fluminea and the gastropod species Elimia livescens), rotifers (Brachionus calyciflorus) and planarians (Dugesia gonocephala). In case of algae, tests on three different green algae species, one diatom species and one blue-algae species are available and were used for HC5-calculation. Fish tests taken into account for HC5-calculation were conducted with rainbow trout, fathead minnow and bluegill (most species tested in several tests). As one representative of higher plants, a study conducted with the aquatic macrophyte Lemna minoris was used.
By using these data the authors first determined EC10-values from the initial test data (i. e. NOEC-values) per endpoint and species. In a second step specific QSAR-models were used to predict toxicity of tested distributions and then toxicity of all pure homologues of alcohol ethoxylates. After construction of a matrix of normalized EC10-values per species, HC5-values were calculated by using the method of Aldenberg and Jaworska (2000). The resulting matrix contains HC5-values for pure homologues of chain lengths C9 to C18 ethoxylated with 0 to 18 ethoxy-groups. These HC5-values were used for the refined calculation of PNEC-values for the alcohol ethoxylate mixtures to be registered. Mixture toxicity is then calculated according to the formula of Finney (1942). Therefore, respectively, minimal and maximal content of a certain pure alcohol ethoxylate available in the mixture is used. In a second step an arithmetic mean of all values is prepared which is used as HC5-value for the mixture. According to the guidance document chapter R.10 an HC5-value normally can be used for PNEC-calculation by taking into account assessment factors of 5 -1. For a further reduction of the assessment factor several criteria need to be fulfilled. According to Belanger et al. (2006) and HERA-report (2009) these criteria, which correspond with the requirements given in the EU TGD (2003) are fulfilled for the data used for the HC5-calculation. HERA-report (2009) listed a detailed justification of an assessment factor of 1 concluding that the confidence of the data used by Belanger et al. (2006) is so high that no further assessment factor is necessary to determine the PNEC freshwater.
Concerning the marine environment, the guidance document chapter R.10 (ECHA, 2008) states that "no marked differences in sensitivity between freshwater and saltwater biota appears that systematically applies across all three trophic levels considered. Differences between trophic levels within each medium were generally as significant or even more marked than between media" (ECHA, 2008, chapter R.10). The fact that no marked difference in sensitivity between freshwater and saltwater biota occur, could be proved for several alcohol ethoxylates. One example are the toxicity of alcohol ethoxylate (C9-11, < 2.5 EO, CAS 68439-46-3) for aquatic invertebrates. Regarding the endpoints for the marine crustacean (brown shrimp) the 96h LC50-value is with 17 mg/L higher than the 48h EC50-value of 2.5 mg/L which was determined for daphnids in the key study. Similar results are reported from other analogue alcohol ethoxylates, such as the alcohol ethoxylate (C12-15, < 2.5 EO, CAS 68131-39-5), where freshwater and marine studies are available for all three trophic levels. Regarding the endpoints determined for the marine crustacean (Acartia tonsa) the determined LC50-value is higher than the EC50-value determined for daphnids (0.88 mg/L for Acartia tonsa versus 0.23 mg/L for Daphnia magna). The same is true comparing the endpoints for growth rate available for the freshwater algae (Selenastrum capricornutum, EC50-value: 0.74 mg/L) with that given for the marine species (Skeletonema costatum, EC50-value: 3.2 - 5.6 mg/L). For fish a direct comparison of the data is not possible as in the available studies alcohol ethoxylates with different degrees of ethoxylation are tested. Concluding from the described comparison of the endpoints available for freshwater and marine species no marked differences in sensitivity could be considered. According to the guideline R.10 in such case PNEC-values should be derived from the most sensitive endpoint regardless of the medium. In case of the alcohol ethoxylates it seems thus valid to use the HC5-value calculated for the wide set of different freshwater species also for the marine compartment with an assessment factor of 1.
Classification related key information
Biodegradation in water: Readily biodegradable: 83.6% (CO2 evolution) in 28 days (OECD 301B)
Bioaccumulation in organisms is negligible, due to biotransformation and excretion of alcohol ethoxylates.
- to Fish: LC50 (96h) = 108 mg/L for Danio rerio
- to Crustacea: EL50 (48h) = 51 mg/L for Daphnia magna
- to Algae: EL50 (72h) > 10 mg/L Pseudokirchneriella subcapitata
The risk assessment is based on alcohol ethoxylate specific QSARs
- to Fish: EC20 (30d) = 0.249 mg/L Pimephales promelas
- to Crustacea: EC20 (21d) = 0.048 mg/L for Daphnia magna
- to Algae: ECr20 = 0.145 mg/L Desmodesmus subspicatus
Classification justification according to CLP
Based on the data above, alcohol ethoxylate ((Z)-9-Octadecen-1-ol ethoxylated, < 2.5 EO, CAS 9004-98-2) is considered rapidly biodegradable. The acute aquatic toxicity L(E)C50 is > 1 mg/L. Based on QSAR calculations the lowest expected long-term effect value is 0.048 mg/L. Therefore, alcohol ethoxylate (C18 -unsaturated, < 2.5 EO) needs to be classified and labelled as environmental hazard Chronic Cat. 2 according to the Regulation (EC) No. 1272/2008 (CLP) (8thATP).
M-factor for acute aquatic toxicity: no factor assigned
M-factor for chronic aquatic toxicity: no factor assigned
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
Welcome to the ECHA website. This site is not fully supported in Internet Explorer 7 (and earlier versions). Please upgrade your Internet Explorer to a newer version.
Close Do not show this message again