Alcohols, C9-11, branched and linear, 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:

14 Aug - 15 Sep 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

2019

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 10.00, 5.00, 2.50, 1.25, and 0.625 mg/L
- Sampling method: samples were taken at test start, after 24 h fresh and aged and after 48 and 72 h from fresh solutions. For test item concentration 10.0 mg/L analytical samples from t = 0 h fresh and t = 24 h aged were analysed as at this highest test concentration all fish were dead after 4-6 h.
- Sample storage conditions before analysis:The samples were mixed with 10 mL acetonitrile and stored deep-frozen (≤ - 18 °C) until analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution was prepared by adding the necessary amount of test item to a volumetric flask. Test medium was added and the solution was homogenised by shaking. The solution was observed to be turbid. Test item concentrations were prepared by dilution with test medium. Test item solutions of 5.00 and 2.50 mg/L (nominal) were observed to be turbid, Test item solutions of 1.25 and 0.625 mg/L (nominal) were observed to clear and transparent.

Test organisms (species):

Pimephales promelas

Details on test organisms:

TEST ORGANISM
- Common name: Fathead minnow
- Source: bred at testing facility
- Weight at study initiation (mean and range, SD): average: 0.28 +/- 0.06 g (10 fish)

ACCLIMATION
- Acclimation conditions (same as test or not): same
- Type and amount of food during acclimation: commercial fish food (inicio plus, BioMar SAS)
- Feeding frequency during acclimation: once per day, last feeding was performed two days prior exposure start
- Health during acclimation (any mortality observed): no

FEEDING DURING TEST (as applicable)
none

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

214 mg CaCO3/L

Test temperature:

21.6 – 22.7 °C

pH:

7.46 – 7.91

Dissolved oxygen:

≥ 76 % of air saturation

Conductivity:

428 µS/cm

Nominal and measured concentrations:

Nominal test item concentrations: 10.0, 5.00, 2.50, 1.25, 0.625 mg/L
Time weighted mean concentrations: 9.27, 4.25, 2.06, 0.860, 0.419 mg/L (based on 3 representative constituents)

Details on test conditions:

TEST SYSTEM
- Test vessel: glass aquaria (18 L nominal volume)
- Type (delete if not applicable): covered with lids
- Fill volume: 15 L
- Aeration: none
- Renewal rate of test solution (frequency): every 24 h
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.09 g fish/L in control group

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dechlorinated drinking water and deionised water
- Total organic carbon: ≤ 2.0 mg/L (non-GLP)
- Culture medium different from test medium: no
- Intervals of water quality measurement: 0 hours from fresh test solutions and after 24, 48, 72 and 96 hours from fresh and aged test solutions

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light/ 8 h darkness
- Light intensity: 610 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality and toxicity symptoms after 0 h, 4-6 h, 1 day (24 h), 2 days (twice per day), 3 days (twice per day) and 4 days (96 h) of exposure.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2.0
- Range finding study
- Test concentrations: 1.0, 10.0, 100 mg/L
- Results used to determine the conditions for the definitive study: 100% mortality at 10 and 100 mg/L

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

6.28 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

other: based on three representative constituents

Remarks:

C10EO2, C10EO3, C10EO6

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

4.25 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

other: based on three representative constituents

Remarks:

C10EO2, C10EO3, C10EO6

Basis for effect:

mortality (fish)

Details on results:

No sublethal effects were observed in the test item concentrations up to and including 2.50 mg/L (nominal) after 96 h.
- Other abnormalities: please see table 2 at "any other information on results incl. tables"
- Mortality of control: no
- Other adverse effects control: no
. The test item solutions in the glass aquaria were clear and transparent.

Reported statistics and error estimates:

The NOEC and LOEC were determined by using a multiple comparison method (Fisher’s exact binomial test with Bonferroni correction). The LC50-value after 4 - 6 h, 24 h, 48 h, 72 h and 96 h was determined following the trimmed Spearman-Karber procedure.

Sublethal observations / clinical signs:

Table 1: Validity criteria for OECD 203 (2019)

Criterion from the guideline	Outcome	Validity criterion fulfilled
The mortality in the control(s) should not exceed 10% (or one fish if less than ten are used) at the end of the test	No mortality observed	yes
The dissolved oxygen concentration must have been at least 60 per cent of the air saturation value throughout the test	≥76%	yes
There must be evidence that the concentration of the substance being tested has been satisfactorily maintained, and preferably it should be at least 80% of the nominal concentration throughout the test. If the deviation from the nominal concentration is greater than 20 per cent, results should be based on the measured concentration.	analytical monitoring performed	yes

Table 2:  % mortality of fish

Test item nominal conc.[mg/L]	Control	0.625	1.25	2.50	5.00	10.0
Time [h]	Mortality [%]
4 – 6	0	0	0	0	0	100
Day 1 (24)	0	0	0	0	0	100
Day 2 (48)	0	0	0	0	0	100
Day 2 (51 - 54)	0	0	0	0	0	100
Day 3 (72)	0	0	0	0	0	100
Day 3 (75 - 78)	0	0	0	0	0	100
Day 4 (96)	0	0	0	0	0	100

Seven fish were used for each replicate in the test

Table 3:  Observation of clinical signs of fish during test

Test item nominal conc.[mg/L]	Control					0.625					1.25
Time [h]	0	°	*	#	+	0	°	*	#	+	0	°	*	#	+
4 – 6	7	0	0	0	0	7	0	0	0	0	7	0	0	0	0
Day 1 (24)	7	0	0	0	0	7	0	0	0	0	7	0	0	0	0
Day 2 (48)	7	0	0	0	0	7	0	0	0	0	7	0	0	0	0
Day 2 (51 - 54)	7	0	0	0	0	7	0	0	0	0	7	0	0	0	0
Day 3 (72)	7	0	0	0	0	7	0	0	0	0	7	0	0	0	0
Day 3 (75 - 78)	7	0	0	0	0	7	0	0	0	0	7	0	0	0	0
Day 4 (96)	7	0	0	0	0	7	0	0	0	0	7	0	0	0	0
Test item conc.[mg/L]	2.50					5.00					10.0
Time [h]	0	°	*	#	+	0	°	*	#	+	0	°	*	#	+
4 – 6	7	0	0	0	0	3	0	4	0	0	0	0	0	0	7
Day 1 (24)	7	0	0	0	0	4	3	0	0	0	0	0	0	0	7
Day 2 (48)	7	0	0	0	0	4	3	0	0	0	0	0	0	0	7
Day 2 (51 - 54)	7	0	0	0	0	3	4	0	0	0	0	0	0	0	7
Day 3 (72)	7	0	0	0	0	7	0	0	0	0	0	0	0	0	7
Day 3 (75 - 78)	7	0	0	0	0	3	4	0	0	0	0	0	0	0	7
Day 4 (96)	7	0	0	0	0	3	4	0	0	0	0	0	0	0	7

0 = no clinical signs

° = unusual behaviour (reduced activity and/or orientation to bottom or surface of the test vessels, dark pigmentation, dark eyes)

* = difficulties with maintenance of equilibrium

# = fish upside down with loss of equilibrium, showing only movement of gills as a sign of life

+ = no sign of life

Validity criteria fulfilled:

yes

Remarks:

Please see table 1 at "any other information on results incl. tables"

Description of key information

LC50 (96 h): 6.28 mg/L (TWA)

Additional information

The acute toxicity of Alcohols, C9-11, branched and linear, ethoxylated to fish was investigated in a GLP guideline study following OECD 203. Seven fish of the species Pimephales promelas were exposed to nominal test item concentrations of 0.0625, 1.25, 2.00, 5.00 and 10.0 mg/L under semi-static conditions. Test solutions were renewed every 24 hours.

The test concentrations were analytically monitored by HPLC-MS/MS. The time weighted mean measured concentrations, based on three representative constituents of the UVCB substance, were 0.419, 0.860, 2.06, 4.25, 9.27 mg/L. No mortalities were observed up to and including a measured concentration of 4.25 mg/L. The determined LC50 (96 h) was 6.28 mg/L (TWA).