Isopentyl acetate

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:

29-7 to 2-8-2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

- To avoid volatility effects the test was carried out without aeration. - Temperature fluctuation exceeded 1 °C --> range 20-24°C. -oxygen content dropped below 60% twice (58 and 56 %)

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

yes

Remarks:

as above

Qualifier:

according to guideline

Guideline:

other: OECD 23: Guidance document on aqueous-phase aquatic toxicity testing of difficult test chemicals

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Oxiteno Europe BVBA
- Purity test date: 99.3 %

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Stability under test conditions: Examined several times by chemical analysis (GC) in the freshly prepared media and in the media after 24 hours of exposure

Analytical monitoring:

yes

Details on sampling:

- Sampling method: analyzed every 24 h
- Sample storage conditions before analysis: immediately analysed

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: To produce the test item concentrations, the calculated amounts of the test item were pipetted every day to the glass aquaria holding 5 L of dilution water. All solutions were then stirred for 0.5 h on magnetic stirrers.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: zebra fish
- Source: Interaquaristik.de Shop (Germany)
- Length at study initiation: mean 3.97 cm (S.D. = 0.22 cm)

ACCLIMATION
- Acclimation period: stock fish acclimated for 4 months
- Acclimation conditions: same as test
- Type and amount of food during acclimation: Commercial fish food, daily. Feeding discontinued 24 h prior to test start.

FEEDING DURING TEST: no feeding

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

not applicable

Hardness:

13.9 °dH (= 248 mg/L CaCO3)

Test temperature:

20 - 24 °C

pH:

7.4-8

Dissolved oxygen:

5.3-9 mg/l

Salinity:

not applicable

Conductivity:

no data

Nominal and measured concentrations:

nominal concentrations: 1.9, 4.3, 9.4, 20.7, 45.5 and 100 mg/L
measured concentration at 96h (mean): 1.095, 2.679, 6.230, 7.394, 39.967, 100.594 mg/L. Effective concentrations ranged from 22.8 % to 111.0 % of nominal values in the freshly prepared media and from 7.9 % to 98.2 % of nominal values in the media after 24 hours of exposure according to the semi-static test conditions.

Details on test conditions:

TEST SYSTEM
- Test vessel: glass aquaria holding 5 L of test media covered by glass plates
- Aeration: none
- Renewal rate of test solution (frequency/flow rate): every 24h
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.8 g body weight (wet weight) per litre

- Intervals of water quality measurement: every 24 h pH, temperature and dissolved oxygen

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

EFFECT PARAMETERS MEASURED: mortality, observation on mortality, incidence of sub-lethal effects compared with controls every 24h

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 1.0, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: yes, all fish were dead at the highest test concentration of 100 mg/L while no dead fish at 10 and 1 mg/L. Since degradation of the test item was observed in the dose range finder, a semi-static test set-up has been used for the main study.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

11.1 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

2 h

Dose descriptor:

LC100

Effect conc.:

14.2 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

24 h

Dose descriptor:

LC100

Effect conc.:

10.9 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

48 h

Dose descriptor:

LC100

Effect conc.:

16.6 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

11.6 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Mortality of control: 14.3 % after 96h

Results with reference substance (positive control):

not applicable

Reported statistics and error estimates:

The LC50 was calculated by probit analysis using the statistics programme ToxRatPro Version 2.10 (released 2010-09-10).

Sublethal observations / clinical signs:

Geometric mean of measured concentrations over time

Date	Exposure time	Measuring time	Test item concentration [mg/L]
			1.9	4.3	9.4	20.7	45.5	100
2019-07-29	0 h	0 h	1.129	3.863	8.698	4.718	42.791	103.008
2019-07-30	24 h	24 h	0.522	1.939	3.921	1.856	37.329	98.236
		0 h	2.029	4.047	9.248	22.975
2019-07-31	48 h	24 h	1.085	1.988	4.396	11.393
		0 h	2.025	2.909	8.768	21.597
2019-08-01	72 h	24 h	0.913	2.072	3.983	5.315
		0 h	1.661	4.082	9.585	20.830
2019-08-02	96 h	24 h	0.520	1.791	4.892	1.630
Results
Geometric mean [mg/L]
	0 h		1.129	3.863	8.698	4.718	42.791	103.008
	24 h		0.768	2.737	5.840	2.959	39.967	100.594
	48 h		1.067	2.786	6.102	6.919	39.967	100.594
	72 h		1.157	2.671	6.037	8.005	39.967	100.594
	96 h		1.095	2.679	6.230	7.394	39.967	100.594

Mortality data (cumulative)

Mortality (initial population: 7)	2 h **	24 h	48 h	72 h	96 h
Control	0	0	1/7 (injured)	1/7	1/7
1.9 mg/L	0	0	0	0	0
4.3 mg/L	0	0	0	0	0
9.4 mg/L	0	0	0	0	0
20.7 mg/L	0	0	0	1/7 (fish removed due to moribund behaviour)	1/7
45.5 mg/L	7/7	7/7	7/7	7/7	7/7
100 mg/L	7/7	7/7	7/7	7/7	7/7

Validity criteria fulfilled:

yes

Conclusions:

Short-term exposure of zebra fish to the test item determined in a semi-static test. The EC50 for mortality based on mean measured concentration is 11.1 mg/L.

Executive summary:

A study was conducted exposing the fish, Danio rerio, to the test item for 96 h. The study as performed following the OECD guideline 203 and fulfilled the validation requirements. Measured concentrations confirmed that test item in the exposure concentrations from 22.8 % to 111.0 % of nominal values in the freshly prepared media and from 7.9 % to 98.2 % of nominal values in the media after 24 hours of exposure according to the semi-static test conditions. Results determined an EC50 for mortality based on mean measured concentration of 11.1 mg/L.

Description of key information

A key study was conducted exposing the fish, Danio rerio, to the test item for 96 h (Neuhahn, 2019). The study as performed following the OECD guideline 203 and fulfilled the validation requirements. Measured concentrations confirmed that test item in the exposure concentrations from 22.8 % to 111.0 % of nominal values in the freshly prepared media and from 7.9 % to 98.2 % of nominal values in the media after 24 hours of exposure according to the semi-static test conditions.Results determined an EC50 for mortality based on mean measured concentration of 11.1 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

11.1 mg/L

Additional information

Two other supporting studies are available:

1) Juhnke and Lüdemann (1978):

The differences for the results of LC0, LC50 and LC100 (48 h) delivered by the two research institutes were not commented in the scientific article (a reason for this is possibly that the scientific article contains results for 200 different substances and it would be an extensive task to comment each one of them). There is no info given, if the origin of the fish used by the two institutes was the same (this could be reason for observed differences). In general, for some of the 200 substances the results also appear to show a great variation, whereas for others the results are not greatly different. Based on this data, the NOEC (48 h) may be < 26 mg/L and the LC50 (48 h) 36 mg/L.

2) Munk, Kirsch and Gelbke (BASF) (1993):

The data was generated with an official test method (OECD TG 203); good documentation of methodology and results. The results are therefore regarded as meaningful: LC50 (96 h): > 22 and < 46 mg/L; NOEC (96 h) = 21.5 mg/L