Alcohols, C12-18, ethoxylated

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.048 mg/L

Assessment factor:

1

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

0.004 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.048 mg/L

Assessment factor:

1

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

10 g/L

Assessment factor:

1

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

292 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

292 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

1 mg/kg soil dw

Assessment factor:

100

Extrapolation method:

assessment factor

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

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.

Conclusion on classification

Classification related key information

Biodegradation in water: Readily biodegradable

Bioaccumulation in organisms is negligible, due to biotransformation and excretion of alcohol ethoxylates

Acute toxicity:

- to Fish: LC50 (96h) = 0.876 mg/L

- to Crustacea: EC50 (48h) = 2.7 mg/L

- to Algae: ECr50 (72h) = 0.41 mg/L

Chronic toxicity:

The risk assessment is based on alcohol ethoxylate specific QSARs

- to Fish: EC20 (30d) = 0.86 mg/L

- to Crustacea: EC20 (21d) = 0.469 mg/L

- to Algae: ECr20 (72h) = 0.714 mg/L

Classification justification according to CLP

Based on the data above, alcohol ethoxylate (C12-18, < 2.5 EO) 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 0.469 mg/L Therefore, alcohol ethoxylate (C12-18, < 2.5 EO) needs to be classified and labelled as environmental hazard Acute Cat. 1 and Chronic Cat. 3 according to the Regulation (EC) No. 1272/2008 (CLP) and the Regulation (EU) No. 286/2011 (2^ndATP).

M-factor for acute aquatic toxicity: 1

M-factor for chronic aquatic toxicity: no factor assigned