Sodium 2-butoxyethyl sulphate

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:

11 Sep - 02 Oct 2017

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:

1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: OECD 126

Version / remarks:

2010

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Landesanstalt für Umwelt, Messungen und Naturschutz Baden-Württemberg, Germany

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Control and 100 mg/L
- Sampling method: 10 mL samples were taken after 4 h and every 24 h; All samples and the control were stabilized (1:1) with acetonitrile
- Sample storage conditions before analysis: All samples were stored deep frozen

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The necessary amount of test item was weighed into a flask and filled up to 2000 mL and was homogenized by shaking
- Controls: yes, only test medium

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish
- Strain: Danio rerio Hamilton, Cypriniformes, Cyprinidae
- Age at study initiation (mean and range, SD): 49 days
- Length at study initiation: 1 and 3 cm
- Method of breeding: Zebrafish were continuously reared in the laboratory of the testing facility.

ACCLIMATION
- Acclimation period: For at least seven days prior to testing the dissolved oxygen was above 80% saturation.
- Acclimation conditions (same as test or not): same
- Feeding frequency during acclimation: The last feeding was performed three days prior test start.
- Health during acclimation: Only fish in good health and free from any apparent malformation were used.

FEEDING DURING TEST
- Food type: The food was obtained from a commercial supplier.
- Amount: The fish were fed each day with granular rearing food with approx. 2% of their body-weight.
- Frequency: The fish were fed each day.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

13°dH corresponding to 232 mg CaCO3/L

Test temperature:

22.7 -24.5 °C (Control)
23.0 - 24.5 °C (100 mg/L)

pH:

7.36 - 7.84 (Control)
7.57 - 8.01 (100 mg/L)

Dissolved oxygen:

90 - 103% (Control)
97 - 102% (100 mg/L)

Conductivity:

712 µS/cm

Nominal and measured concentrations:

Control and 100 mg/L

Details on test conditions:

TEST SYSTEM
Test vessel:
- Type: open
- Material, size, headspace, fill volume: 2 L glass beakers, filled with 2 L of test solution.
- Aeration: Continuous aeration of the test vessels with a membrane pump using a Pasteur pipette.
- No. of organisms per vessel: 7 organisms for the test concentration and the control were used
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: max. loading of 0.389 g fish/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Test medium was water composed reconstituted test water consisting of analytical grade salts dissolved in purified water with a ratio of Ca:Mg and Na:K of 4:1 and 10:1, respectively, based on molarity, and a conductivity of 712 µS/cm.
- Culture medium different from test medium: no
- Intervals of water quality measurement: in 24 h interval

OTHER TEST CONDITIONS
- Photoperiod: 16 h light / 8 h dark

EFFECT PARAMETERS MEASURED: Cumulative Mortality and Behavioral Observations; at 0, 4, 24, 48, 72 and 96 h. Fish were considered dead if there was no visible movement (e.g. gill movement), and if touching of the caudal peduncle produced no reaction.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: No sublethal effects were observed in the control and in the limit test item concentration of 100 mg/L after 96 h.
- Observations on body length and weight: All fish were weighed and measured at test end. The average weight of the test organisms was 0.111 ± 0.023 g; the average length was 24 ± 2 mm.
- Mortality of control: No control mortality was observed.

Sublethal observations / clinical signs:

Table 1: Determined concentrations of the test item during the test

Test item nominal	Test Item	Sampling	Test Item
[mg/L]	[mg/L]		[mg/L]	% of nominal
0	0	0 h fresh	n.d.	-
		96 h aged	n.d.	-
100	100	0 h fresh	97.5	98
		96 h aged	99.3	99

LOQ = 1.00 mg/L test item; n.d. = not detectable; - = not calculable

Table 2: Validity criteria

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	In this study no control mortality was pobserved	yes
The dissolved oxygen concentration must have been at least 60 per cent of the air saturation value throughout the test	the dissolved oxygen concentration was ≥ 90% throughout the test	yes

Validity criteria fulfilled:

yes

Conclusions:

No effects were observed up to the test item concentration of 100 mg/L therefore the EC50 was determined to be at >100 mg/L and the NOEC at 100 mg/L.

Description of key information

LC50 (96h) >100 mg/L (Danio rerio, OECD 203, nominal)

Additional information

One experimental study is available investigating the toxicity of the substance to fish. The study was conducted according to OECD 203 (GLP) using the zebrafish Danio rerio as test species (Eurofins, 2017a). Since no effects were observed for Daphnia and Algae up to the test material concentration of 100 mg/L, the test was performed as limit test with a test item concentration of 100 mg/L following the threshold approach (OECD 216). The measured content of the test item in the fresh test solution was 98% of nominal and in aged test solution 99% of nominal. Therefore the results are given based on nominal concentrations. No sublethal effects were observed until the end of the 96 hours test duration. Hence the LC50 (96 h) was determined to be > 100 mg/L.