Alcohols, C11-15-secondary, ethoxylated

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

long-term toxicity to fish, other

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1. CALCULATION: EC10 = 10-0.280 log Kow+1.90 (Boeije et al 2006)

2. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
- Defined endpoint: EC10
- Unambiguous algorithm: 10-0.280 log Kow+1.90
- Defined domain of applicability: the training set includes alcohol ethoxylate mixtures (C9-11AE6, C12-13AE6.5, C12-15AE6, C12-15AE9, C13-15AE5 or C14-15AE7) and with the range of Log Kow is 3.65 to 5.91 (calculation based on Leo and Hansh, 1979)
- Appropriate measures of goodness-of-fit and robustness and predictivity:
- Mechanistic interpretation:based on nonspecific membrane disruption being the mode of action for all AE toxicity, which means that toxicity is related to the hydrophobicity and thus the Kow of the specific AE homologue .

3. APPLICABILITY DOMAIN
- Descriptor domain: log kow of 5.3 (predicted using Episuite which is based on Leo and Hansch calculation). It is difficult to get accurate results for experimental determinations of Log Pow of surfactants.
- Structural and mechanistic domains: C11-15AE3
- Similarity with analogues in the training set: the log Kow is in the middle of the training set range and structurally it has bigger distribution of the alkyl chain length with a shorter ethoxylated chain.
- Other considerations (as appropriate):Although toxicity was found to decrease with increasing ethylene oxide chain length, secondary attachments of the alkyl group were reported to be less chronically toxic than linear primary AE.

4. ADEQUACY OF THE RESULT
Due to the insufficient number of data points (three early life stage studies), this cannot be considered a reliable QSAR, but it is given for completeness. However the fish is not the most sensitive of the aquatic organisms to AE.

Principles of method if other than guideline:

- Principle of test: A new QSAR technique for complex substances, which interprets the mixture toxicity with regard to the‘‘ethoxymers’’ distribution (i.e., the individual AE components) rather than the average structure, was developed (Boeije et al, 2006) using the Log Kow.
- Short description of test conditions: 30-day study
- Parameters analysed / observed: NOEC for chronic Fish (survival)

Duration:

32 d

Dose descriptor:

EC10

Effect conc.:

0.87 mg/L

Conc. based on:

test mat.

Basis for effect:

other: egg survival

Remarks on result:

other: Pimephales promelas

Remarks:

QSAR

Validity criteria fulfilled:

yes

Reference 2

Endpoint:

long-term toxicity to fish, other

Type of information:

other: Review of the ecotoxicology profile similarity between softanol 30 and the alcohol ethoxylates described in several publications and assessment of data from available studies to waive the execution of a long term fish study

Adequacy of study:

weight of evidence

Reliability:

other: Review of data extracted from publications

Principles of method if other than guideline:

This is a review of the ecotoxicology profile between softanol 30 and the alcohol ethoxylates described in several publications. The aim is to assess the similarity of the data from available studies with softanol 30 and other alcohol ethoxylates in order to confirm the applicability of the chronic fish QSAR and waive the execution of a long term toxicity study to fish with softanol 30.
The notifier has performed acute toxicity studies to aquatic organisms with softanol. Acute and long-term toxicity laboratory and field studies to fish toxicity studies are available with other alcohol ethoxylates.

Duration:

30 d

Dose descriptor:

NOEC

Effect conc.:

0.18 mg/L

Conc. based on:

test mat.

Basis for effect:

other: Fathead minnow larvae survival

Remarks on result:

other: C14-15AE7

Remarks:

in lab study

Duration:

12 mo

Dose descriptor:

NOEC

Effect conc.:

0.32 mg/L

Conc. based on:

test mat.

Basis for effect:

other: Fathead minnow survival and reproduction lab study

Remarks on result:

other: C12-15AE6,5

Remarks:

in lab studies

Duration:

10 d

Dose descriptor:

NOEC

Effect conc.:

0.16 mg/L

Conc. based on:

test mat.

Basis for effect:

other: Fathead minnow survival

Remarks on result:

other: C14-15AE7

Remarks:

in lab studies

Duration:

10 d

Dose descriptor:

LOEC

Effect conc.:

0.46 mg/L

Conc. based on:

test mat.

Basis for effect:

other: Fathead minnow survival

Remarks on result:

other: C14-15AE7

Remarks:

in lab studies

Duration:

30 d

Dose descriptor:

NOEC

Effect conc.:

0.28 mg/L

Conc. based on:

test mat.

Basis for effect:

other: Fathead minnow survival

Remarks on result:

other: C14-15AE7

Remarks:

in outdoor stream mesocosms

Description of key information

Chronic fish endpoint was calculated using a Chronic QSAR algorythm developed by Boeije et al (2006)

Fish survival EC10 = 10^{-0.280 log Kow+1.90}= 2.61 μmol/L (0.87 mg/L)

For softanol 30, the log Kow is estimated to be 5.3; molar-to-mass conversions were carried out using its Mw of 334.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0.87 mg/L

Additional information

A new long-term toxicity study to fish with softanol 30 is waived due to availability of data on other ethoxylated alcohols and a chronic QSAR developed for alcohol ethoxylates by Boeije et al (2006). This QSAR was used to calculate the EC10 for softanol 30.