2-morpholinoethanesulphonic acid

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:

2017-11-27 to 2018-06-16

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:

17 July 1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Version / remarks:

May 30, 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1075 (Freshwater and Saltwater Fish Acute Toxicity Test)

Version / remarks:

October 2016

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

For determination of the test item concentration, samples of the test concentration and control were taken from the test solutions at the start and at the end of the study. Six parallel samples were analysed from the test concentration and two from the control at the start and at the end of the test.

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
The test solution used in the test was prepared by mechanical dispersion. An amount of 0.5407 g test item was dissolved in 5000 mL dilution water (ISO medium), resulting a nominal concentration of 108 mg/L. The test solution was freshly prepared in the testing laboratory just before introduction of fish.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish
- Source: Akvárium magazon Kft. (Pasaréti Gyula), 1222 Budapest, Dévény u. 36, Hungary
- Age at study initiation: Juveniles
- Length at study initiation: within a range of 2.0 ± 1 cm

ACCLIMATION
Fish were held for at least 12 days before test initiation in the fish laboratory under the same conditions as used during the exposure period. During holding, fish were fed with appropriate, commercial diet for fish at least three times per week until one day before the test start. The health of the breeding was continuously monitored and any mortality or abnormal behaviour recorded. No significant mortality (less than 5 % of population) occurred in seven days before the start of the experiment, therefore the batch was considered to be acceptable for testing.

FEEDING DURING TEST: No

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

approximate theoretical total hardness of 249 mg/L (as CaCO3)

Test temperature:

21.6 – 22.4 °C

pH:

6.52 – 7.60

Dissolved oxygen:

73.8 – 92.5 %

Salinity:

not applicable

Conductivity:

not specified

Nominal and measured concentrations:

Nominal concentration: 100 mg/L
Measured concentration: concentrations reported as nominal as recovery was 98.6 – 102.5 %

Details on test conditions:

TEST SYSTEM
- Test vessel: aquarium with 5 L test solution
- Type: closed
- Aeration: no
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.33 - 0.40 g/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted water (ISO medium, prepared according to Annex 2 of the OECD guideline 203)

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours light (artificial illumination) and 8 hours darkness

EFFECT PARAMETERS MEASURED:
Observations at approximately 4, 24, 48, 72 and 96 hours after start of the test for signs of intoxication and mortality.
The body length of each fish was measured at the end of the test in order to check their compliance with the size range recommended for the species by the test guideline (OECD No. 203).

TEST CONCENTRATIONS
- Range finding study: Yes
- Test concentrations: 100 mg/L
- Results used to determine the conditions for the definitive study: Yes

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 108 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

108 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

108 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LOEC

Effect conc.:

> 108 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

> 108 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: no information
- Observations on body length and weight: Observed, but normal development
- Other biological observations: no
- Mortality of control: no
- Other adverse effects control: no
- Abnormal responses: no
- Any observations that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: no effects observed

Results with reference substance (positive control):

not reported

Sublethal observations / clinical signs:

Validity of the Study

 - There was no mortality observed in control or in the treatment group during the study.

 - The dissolved oxygen concentration in the test solutions did not fall below 60 % of air saturation value during the study.

 - No significant change (more than one unit) in the pH value was observed during the test.

 All validity criteria were within acceptable limits and therefore the study can be considered as valid.

Table 1: Summary of the Biological Endpoints

Endpoint	Concentration [mg/L]
96-h LC50	> 108
96-h NOEC	108
96-h LC0	108
96-h LOEC	> 108
96-h LC100	> 108

 

Table 2: Cumulative mortality data in the definitive test

Test Group	Cumulative mortality (initial population = 10 fish / test group)
	5 h	24 h	48 h	72 h
Control 108 mg/L	0	0	0	0
	0	0	0	0

 

Table 3: Measured and calculated data of body weight

Test Group	Measured weight of 10 fish (g)	Calculated mean weight of 1 fish (g)	Loading of testing aquarium (g fish/L testing liquid)
Control	11.99	0.199	0.40
108 mg/L	1.67	0.167	0.33

 

Table 4: Body length of test animals

Test Group	Body length [cm]
Control	2.35	2.60	2.40	2.45	2.35	2.40	2.50	2.30	2.50	2.50
108 mg/L	2.20	2.25	2.30	2.45	2.40	2.60	2.35	2.20	2.40	2.10

 

RESULTS OF THE ANALYSIS

A single concentration of 108 mg/L (limit test) and a concurrent control were tested in the main test. The concentration of the test item was analytically determined in the test item solution at the start and at the end of the experiment. In the untreated control group the test item was not detected. The measured concentration of the test item was 106.5 % of the nominal at the start and 110.7 % at the end of the test. The measured test item concentration remained within ± 20 % of the nominal during the test period of 96 hours. Therefore, the biological results are based on the nominal test item concentration.

 

Table 5. Concentration of Test Item measured in the Test Solutions

      

Nominal Concentration, mg/L	Measured concentrations, mg/L
	Start	End
108	107.5	110.9
	108.2	109.7
	105.3	111.7
	107.9	109.5
	103.3	110.6
	106.7	111.9
Mean:	106.5	110.7

 

Validity criteria fulfilled:

yes

Conclusions:

In this 96-h acute toxicity test on Zebrafish (Brachydanio rerio) the test item had no toxic effect on fish up to a concentration of 108 mg/L. Accordingly, the 96-h LC50 value was determined to be > 108 mg/L and the 96-h NOEC was determined to be 108 mg/L.

Executive summary:

The objective of this study was to evaluate the acute toxicity of the test item on Zebrafish (Brachydanio rerio) according to OECD TG 203 under GLP. For this purpose, young fish were exposed to aqueous test media containing the test item for 96-h. Based on results obtained in a preliminary experiment fish were exposed to a single concentration of 108 mg/L (limit test). A concurrent control group was run. A static test was performed as the test item was previously shown to be stable in the test medium over the test period. The analytically measured test item concentration remained within ± 20 % of the nominal during the test period of 96 hours; therefore the biological results are based on the nominal concentration. The fish were observed at approximately 4, 24, 48, 72 and 96 hours after start of the test for signs of intoxication and mortality. Measurements of pH, dissolved oxygen and temperature were carried out daily. The test medium was fully characterized (content, physicochemical characteristics). All validity criteria were met. Mortality and any sub-lethal effects were not observed during the 96-h exposure period, neither in the treated nor in the control group. The 96-h NOEC was determined as 108 mg/L and the 96-h LC₅₀ as > 108 mg/L.

Description of key information

The 96-h LC₅₀ value was determined to be > 108 mg/L and the 96-h NOEC was determined to be 108 mg/L (reference 6.1.1-1).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

108 mg/L

Additional information

The objective of this study was to evaluate the acute toxicity of the test item on Zebrafish (Brachydanio rerio) according to OECD TG 203 under GLP. For this purpose, young fish were exposed to aqueous test media containing the test item for 96-h. Based on results obtained in a preliminary experiment fish were exposed to a single concentration of 108 mg/L (limit test). A concurrent control group was run. A static test was performed as the test item was previously shown to be stable in the test medium over the test period. The analytically measured test item concentration remained within ± 20 % of the nominal during the test period of 96 hours; therefore the biological results are based on the nominal concentration. The fish were observed at approximately 4, 24, 48, 72 and 96 hours after start of the test for signs of intoxication and mortality. Measurements of pH, dissolved oxygen and temperature were carried out daily. The test medium was fully characterized (content, physicochemical characteristics). All validity criteria were met. Mortality and any sub-lethal effects were not observed during the 96-h exposure period, neither in the treated nor in the control group. The 96-h NOEC was determined as 108 mg/L and the 96-h LC₅₀ as > 108 mg/L.