Alcohols, C11-15-secondary, ethoxylated

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08 June 2010 - 08 September 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted in accordance with international guidelines, and in compliance with GLP.

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0.0970, 0.213, 0.470, 1.03, 2.27 and 5 mg/L as WAF
- Sampling method: At the start of the definitive test and on Day 3, replicate samples (50 mL) were taken from the freshly prepared control and test media. On Days 1 and 4 replicate expired samples (50 mL) of media were taken from each tank.
- Sample storage conditions before analysis: On each occasion, both replicate samples were stored in a freezer until analysis was performed

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)

- Method: At each concentration, the test substance (4 or 9 µL, 18.8, 20.6, 45.4 or 100 mg) was dispersed in dechlorinated tap water in a glass vessel (20 or 40 L). The contents of each vessel were stirred for approximately 24 hours in the dark and then left to stand for approximately 24 hours. Aliquots (15 L) were then removed mid vessel to provide the Water Accommodated Fraction (WAF’s) at a nominal loading rates of 0.0970, 0.213, 0.470, 1.03, 2.27 and 5 mg/L.

- Evidence of undissolved material (e.g. precipitate, surface film, etc): At all concentrations, the test media were colourless dispersions.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow Trout
- Source: Commercial fish farm in the UK
- Age at study initiation (mean and range, SD): Not specified, but calculated to be between 6-10 weeks.
- Length at study initiation (length definition, mean, range and SD): Mean total length was 4.92 cm.
- Weight at study initiation (mean and range, SD): Mean wet weight was 1.38 g
- Feeding during test: No food was given during the 19-hour period immediately before exposure or during the exposure period itself.

ACCLIMATION
- Acclimation period: 14 days
- Acclimation conditions (same as test or not): No, the fish were held in an aerated supply of diluent water under flow-through conditions until use.
- Type and amount of food: Commercial fish food at an amount equivalent 2% of the total wet-weight of fish in the holding tank.
- Feeding frequency: Daily.
- Health during acclimation (any mortality observed): No medication was given during the holding period, and mortality was recorded as 2% in the 14 days before the definitive test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

None

Test temperature:

15±2°C.

pH:

Control solutions: 8.07 - 8.39
Expired solutions: 8.04 - 8.43

Dissolved oxygen:

Fresh solutions: 8.7 - 9.4 mgO2/L
Expired solutions: 9.2 - 9.5 mgO2/L

Salinity:

Not applicable for a freshwater study.

Nominal and measured concentrations:

Nominal concentrations: 0.0970, 0.213, 0.470, 1.03, 2.27 and 5 mg/L as WAF.
At nominal loading rates of 0.970, 0.213, 0.470 and 1.03 mg/L, the levels of TOC measured in the test media were below that found in the control media on one or more occasions during the definitive test; therefore, it was not possible to quantify the level of carbon that was attributable to the test substance at these exposure levels.

At loading rates of 2.27 and 5 mg/L, the levels of TOC measured in samples of the test media were 0.260 and 1.21 mgC/L (after correction for the control) in samples of freshly prepared media and 0.928 and 2.95 mgC/L in samples of expired (24-hour-old) media. Based on a geometric mean, the overall measured TOC levels were 0.486 and 1.89 mgC/L.

Due to the complex composition of Softanol 30, oxidation of the organic carbon may have been incomplete under analytical conditions employed, so the levels of TOC measured in the test media may have been underestimated.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: glass aquaria, filled to a depth of 17.3 cm (15 litres of dilution water or test solution).
- Aeration: Supplementary aeration was provided via narrow bore glass tubes.
- Renewal rate of test solution (frequency/flow rate): Semi-static - daily batch renewal of the media to ensure the maintenance of satisfactory environmental conditions and in an attempt to maintain stable exposure levels.
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates):1
- No. of vessels per control (replicates):1
- Biomass loading rate: 0.644 g bodyweight/litre

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Filtered dechlorinated tap water blended with tap water that had been softened and subsequently treated by reverse osmosis to a hardness of 150-200 mg/L as CaCO3.
- Total organic carbon: 1.1 mg/L
-Calcium: 43 mg/l
- Magnesium: 2.0 mg/l
- Ca/mg ratio: 43/2.0 (=21.5)
- Conductivity: 240 uS/cm
- Culture medium different from test medium: No

OTHER TEST CONDITIONS
- Adjustment of pH: None
- Photoperiod: 16h light : 8h dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Mortality, defined as absence of respiratory movement, and absence of response to physical stimulation of the caudal peduncle. Observations were
taken at approximately 2, 4, 24, 48, 72 and 96 hours.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2-fold
- Range finding study test concentrations: not reported. Results used to determine the conditions for the definitive study: Yes

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

1.53 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL 1.03 - 2.27

Duration:

96 h

Dose descriptor:

NOELR

Effect conc.:

0.47 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: They were observed at 1.03 mg/L and higher concentrations and comprised of lethargy, darkened pigmentation, hyperventilation, loss of orientation and immobility.
- Mortality of control: None
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: At all concentrations, the test media were colourless dispersions. Due to the complex composition of Softanol 30, oxidation of the organic carbon may have been incomplete under analytical conditions employed, so the levels of TOC measured in the test media may have been underestimated.

Results with reference substance (positive control):

Not applicable

Sublethal observations / clinical signs:

Highest nominal loading rate resulting in no mortality: 1.03 mg/L WAF.

Lowest nominal loading rate resulting in 100% mortality: 2.27 mg/L WAF.

Validity criteria fulfilled:

yes

Remarks:

Environmental parameters remained within acceptable limits throughout the duration of the study.

Conclusions:

The 96 h LL50 value for Softanol 30 with rainbow trout was 1.53 mg/L.
The no-observed effect loading rate (NOELR) for DEGDB with rainbow trout was 0.470mg/L.

Executive summary:

A study was performed to assess the acute toxicity of Softanol 30 to rainbow trout (Oncorhynchus mykiss) under semi-static conditions with daily renewal of the media.

 

The study was conducted in accordance with EC Methods for Determination of Ecotoxicity, Annex to Commission Regulation (EC) No 440/2008 (O.J. No. L142/446, 2008) Part C, Method 1 “Acute Toxicity For Fish” and the OECD Guideline for Testing of Chemicals No. 203 “Fish, Acute Toxicity Test” (1992).

 

Groups of seven juvenile fish were exposed to water accommodated fractions (WAFs) of Softanol 30 prepared from aqueous mixtures with initial nominal concentrations (loading rates) of 0.0970, 0.213, 0.470, 1.03, 2.27 and 5 mg/L. The test media were prepared in dechlorinated tap water by the direct addition of the test substance to the dilution medium. To aid dissolution, the aqueous mixtures were stirred for approximately 24 hours and then left to stand for approximately 24 hours before the aqueous phase (WAF) was removed and used as the test medium at each concentration.

The multi-component nature of the test substance made it unsuitable for analysis using chromatographic methods. Consequently, exposure levels were monitored using carbon analysis (Total Organic Carbon, TOC) during the test.

 

At nominal loading rates of 0.970, 0.213, 0.470 and 1.03 mg/L, the levels of TOC measured in the test media were below that found in the control media on one or more occasions during the test, therefore, it was not possible to quantify the level of carbon that was attributable to the test substance at these exposure levels.

 

At loading rates of 2.27 and 5 mg/L, the levels of TOC measured in samples of the test media were 0.260 and 1.21 mgC/L (after correction for the control) in samples of freshly prepared media and 0.928 and 2.95 mgC/L in samples of expired (24-hour-old) media. Based on a geometric mean, the overall measuredTOC levels were 0.486 and 1.89 mgC/L.

Observations of the fish were made after approximately 2, 4, 24, 48, 72 and 96 hours of exposure.

 

After 96 hours, the highest nominal loading rate at which no mortality had occurred was 1.03 mg/L and the lowest at which there was 100% mortality was 2.27 mg/L. Treatment‑related effects were exhibited at 1.03 mg/L and higher concentrations.

 

Based on these findings the following values have been estimated:

Nominal loading rates (WAFs): 

96-hour LL₅₀value: 1.53 mg/L (95% confidence limits of 1.03, 2.27 mg/L)

NOELR (No Observed Effect Loading Rate): 0.470 mg/L

Description of key information

One study is available and valid.
In a 96 -h acute toxicity study, rainbow trout (Oncorhynchus mykiss) (7/group) were exposed to Softanol 30 at nominal concentrations of 0 (control), 0.0970, 0.213, 0.470, 1.03, 2.27 and 5 mg/L as Water Accommodated Fractions (Huntingdon Life Sciences, 2010, report PLZ0026. Mortalities were observed at the top two levels, 2.27 and 5 mg/L. The 96-hour LL50value for Softanol 30 with rainbow trout was 1.53 mg/L WAF, with 95% confidence limits of 1.03 and 2.27mg/L. The “no observed effect loading rate” (NOELR) was 0.470 mg/L WAF.
This toxicity study is classified as acceptable and fully satisfies the guideline requirement for short-term toxicity to fish.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

1.53 mg/L