Tributylethylammonium ethyl 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:

08 May 2017 - 03 August 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

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples for analysis were taken from all test concentrations and the control according to the schedule below:
Frequency at t=0 h and t=96 h
Volume 2.0 mL
Storage Samples were stored in a freezer (≤-15°C) until analysis

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Direct application to the test medium: preparation of test solutions started with the highest concentration of 100 mg/L (37 mg anion/L) in the range-finding test and 272 mg/L (100 mg anion/L) in the final test. Since the test item was completely soluble in test medium, no other treatment than vigorous shaking was needed to completely dissolve the test item in medium. Lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium.
- Controls: Test medium without test item or other additives.
- Evidence of undissolved material: All test solutions were clear and colorless at the end of the preparation procedure.

Test organisms (species):

Cyprinus carpio

Details on test organisms:

TEST ORGANISM
- Common name: carp
- Strain: Linnaeus, 1758
- Source: Zodiac, proefacc, "De Haar Vissen", Wageningen University and Research Centre, The Netherlands
- Age at study initiation: >12 days
- Length at study initiation (final test): 3.1 ± 0.1 cm
- Weight at study initiation (final test): 0.45 ± 0.03 g
- Method of breeding: in UV-treated water

ACCLIMATION
- Acclimation period: at least 12 days
- Acclimation conditions: same as test
- Feeding frequency and feed type during acclimation: daily with pelleted fish food (Essence (300-500 um), Coppens International bv, Helmond, The Netherlands)
- Health during acclimation: mortality during the seven days prior to the start of the test was less than 5%

FEEDING DURING TEST: no

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

180 mg CaCO3/L

Test temperature:

At test initiation: 21.0°C
Throughout the test: 20.7-21.0°C

pH:

At test initiation: 7.9
Throughout the test: 7.4-8.0

Dissolved oxygen:

At test initiation: 8.9-9.0 mg O2/L
Throughout the test: 5.3-8.6 mg O2/L

Nominal and measured concentrations:

Nominal concentrations: 27, 49, 87, 151 and 272 mg test item/L (corresponding to 10, 18, 32, 56 and 100 mg anion/L)
Measured concentrations at t=0: 282 mg test item/L based on the anion concentration and 296 mg test item/L based on the cation concentration.
Concentrations at t=96 were 105% of initial in the test solution based on the anion concentration and 110% of initial based on the cation concentration.
Based on these results the effect concentrations were based on the nominal concentrations mg test item/L calculated from the nominal concentrations of anion.

Details on test conditions:

TEST SYSTEM
- Test vessel: 6.5 litres, all-glass, fill volume: 5.0 litres
- Aeration: no aeration was applied up until 72 hours into the exposure period. Aeration was introduced after 72 hours of exposure as the oxygen concentration had dropped below the optimum level for testing with carp, i.e. below 5 mg/L.
- No. of organisms per vessel: 7
- No. of vessels per concentration: 1
- No. of vessels per control: 1
- Biomass loading rate: 0.63 g fish/L

TEST MEDIUM / WATER PARAMETERS
- Test medium used: adjusted ISO medium according to OECD guideline 203
- Source/preparation of dilution water: tap-water purified by reverse osmosis
- Intervals of water quality measurement: dissolved oxygen content, pH and temperature were measured daily in all vessels, beginning at the start of the test (day 0).

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours, daily

EFFECT PARAMETERS MEASURED: mortality at t= 3, 24, 48, 72 and 96 hours

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 0.10, 1.0, 10 and 100 mg test item/L (corresponding to 0.037, 0.37, 3.7 and 37 mg anion/L)
- Results used to determine the conditions for the definitive study: yes; no mortality was observed at any of the test concentrations during the test period. One of the fish exposed to the highest concentration was observed to have lost colour after the exposure period and from 72 hour of exposure showed loss of equilibrium. The two remaining fish showed no effects during exposure and therefore, it was assumed that the observed effects were not test item related. Based on these results, the EC50 was expected to exceed 100 mg test item/L in the final test. It was decided to test the test item up to and including a concentration of 100 mg anion/L which corresponds to 272 mg test item/L to cover the full range for both ions.

Reference substance (positive control):

yes

Remarks:

Pentachlorophenol (February 2017)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 272 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

other: anion

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 172

Nominal / measured:

nominal

Conc. based on:

other: cation

Basis for effect:

mortality (fish)

Remarks on result:

other: cation concentration calculated

Details on results:

- No mortality was observed during the exposure period in any of the treatment groups and the controls.
- Analysis showed that the test item concentration, based on the measured concentration of the anion, was 105% of initial concentrations after the 96 hour exposure period. Therefore, the LC50 was expressed as the nominal concentration mg test item/L.
- No other abnormal effects were observed.
- All test conditions remained within the ranges prescribed by the study plan (pH: 6.0-8.5, constant within 1 unit; temperature 20-24°C, constant within 2°C; oxygen > 60% of air saturation).

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Mortality: all carp exposed to a concentration of 0.46 mg reference item/L died within 24 hours, while no mortality occurred at 0.10 and 0.22 mg/L.
- LC50: 0.32 mg/L (95 % confidence interval between 0.22 and 0.46 mg/L)
- Other: since the results with the reference substance were within the historical data range, the sensitivity of carp originating from the present batch for PCP falls within the range of sensitivities generally observed during the past years.

Reported statistics and error estimates:

No statistical analysis was performed since the test item proved to be non-toxic at the highest tested concentration.

Sublethal observations / clinical signs:

Table 1 Measured concentrations (anion) versus nominal concentrations

Time of sampling [hours]	Date of sampling	Date of analysis^1	Concentration [mg/L]		Relative to nominal [%]	Relative to initial [%]
			Nominal	Analyzed
0	17 Jul 2017	02 Aug 2017	0	< 1	n.a.
			272	282	104
96	21 Jul 2017	02 Aug 2017	0	< 1	n.a.
			272	296	109	105

¹      Samples were stored in the freezer (≤ -15°C) until the day of analysis.

n.a.Not applicable.

Table 2 Measured concentrations (cation) versus nominal concentrations

Time of sampling [hours]	Date of sampling	Date of analysis^1	Concentration [mg/L]		Relative to nominal [%]	Relative to initial [%]
			Nominal	Analyzed
0	17 Jul 2017	02 Aug 2017	0	< 0.1	n.a.
			272	290	107
96	21 Jul 2017	02 Aug 2017	0	< 0.1	n.a.
			272	319	117	110

¹     Samples were stored in the freezer (≤ -15°C) until the day of analysis.

n.a.Not applicable.

Table 3 Incidence of Mortality and Total Mortality During the Final Test

TBEAES DRY Nominal concentration (mg anion/L)	Initial Number of fish	Cumulativemortality					Total Mortality (%)
		3h	24h	48h	72h	96h
Control	7	0	0	0	0	0	0
10 (27)	7	0	0	0	0	0	0
75 (49)	7	0	0	0	0	0	0
32 (87)	7	0	0	0	0	0	0
56 (151)	7	0	0	0	0	0	0
100 (272)	7	0	0	0	0	0	0

() – between brackets, the concentration of the test item are given (mg/L)

Validity criteria fulfilled:

yes

Remarks:

see 'overall remarks'

Conclusions:

Based on the results of an acute toxicty study in fish, performed according to OECD guideline 203 and GLP principles, the LC50 of TBEAES DRY was >272 mg/L.

Executive summary:

An acute toxicity study in fish was performed according to OECD guideline 203 and GLP principles, to assess the effect of TBEAES DRY on carp after 96 hours of exposure. The test item concentration was corrected for the concentration of anion with a correction factor of 0.368.

Test solutions were prepared by adding the test item directly to the test medium and shaking the solutions vigorously for complete dissolution of the test item. A combined limit/range-finding test was performed with test concentrations of 0.1, 1.0 and 100 mg/L (0.037, 0.37 and 3.7 mg anion/L). Since no effects were observed in the range-finding study, the test item was tested in a final test at the following concentration range: 27, 49, 87, 151 and 272 mg test item/L (corresponding to 10, 18, 32, 56 and 100 mg anion/L) in the final test.

Seven fish (Cyprinus carpio) were exposed to the test item under static conditions for a period of 96 hours in which mortality was recorded at t=3, 24, 48, 72 and 96 hours. Samples were taken from the control and the highest test concentration at the start and the end of the test for confirmation of actual exposure concentrations. The analysis was based on the concentration of anion and cation in the test solutions. The measured concentration of the anion was 105% of the initial concentration after the 96 hour test period and for the cation 110% of the initial concentration. Therefore, the effect parameter was based on the nominal test item concentration.

No mortality or other abnormalities were observed in any of the treatment groups and the controls. Therefore, the LC50 was determined to exceed the test item concentration of 272 mg/L (100 mg anion/L). All acceptability criteria were met and the study was considered to be valid.

Description of key information

An acute toxicity study in fish was performed according to OECD guideline 203 and GLP principles, to assess the effect of TBEAES DRY on carp after 96 hours of exposure. The test item concentration was corrected for the concentration of anion with a correction factor of 0.368.  Test solutions were prepared by adding the test item directly to the test medium and shaking the solutions vigorously for complete dissolution of the test item. A combined limit/range-finding test was performed with test concentrations of 0.1, 1.0 and 100 mg/L (0.037, 0.37 and 3.7 mg anion/L). Since no effects were observed in the range-finding study, the test item was tested in a final test at the following concentration range: 27, 49, 87, 151 and 272 mg test item/L (corresponding to 10, 18, 32, 56 and 100 mg anion/L) in the final test. Seven fish (Cyprinus carpio) were exposed to the test item under static conditions for a period of 96 hours in which mortality was recorded at t=3, 24, 48, 72 and 96 hours. Samples were taken from the control and the highest test concentration at the start and the end of the test for confirmation of actual exposure concentrations. The analysis was based on the concentration of anion and cation in the test solutions. The measured concentration of the anion was 105% of the initial concentration after the 96 hour test period and for the cation 110% of the initial concentration. Therefore, the effect parameter was based on the nominal test item concentration. No mortality or other abnormalities were observed in any of the treatment groups and the controls. Therefore, the LC50 was determined to exceed the test item concentration of 272 mg/L (100 mg anion/L). All acceptability criteria were met and the study was considered to be valid.