Isopentyl acetate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16/20-07-2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

2008

Deviations:

yes

Remarks:

uncritical deviation: water hardness 257 mg/L CaCO3, reccomended range 14-250 mg/L CaCO3

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

2004

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 by chemical analys (GC) at 0, 24 and 48 hours.

Analytical monitoring:

yes

Details on sampling:

- Concentrations: at 0, 3.13, 6.25, 12.5, 25, 50 and 100 mg/L
- Sampling method: Control: at 48h. Treatments: at 0 and 48 h (sampling also at 24h at highest concentration of 100 mg/L)
- Sample storage conditions before analysis: The samples were analysed immediately after sampling

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A stock solution was prepared to give the desired series of test concentrations. 573 µL (= 100 mg/L) of the test item were added to 5 litres of dilution water and stirred for 0.5 h on a magnetic stirrer. The pH was measured to be 7.9.
To produce the different test item concentrations appropriate amounts of the stock solution were diluted with dilution water to a volume of 1000 mL. 250 mL – 300 mL of the prepared solutions were taken per replicate and were filled in a closed bottle system and 0.5 mL of dilution water containing 5 daphnids was given to all replicates resulting in the final nominal concentrations. All bottles were sealed with glass stoppers. For each test item exposure concentration and for the control exposure 6 replicates were prepared.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: Strain of Bundesgesundheitsamt Berlin
- Stage and instar at study initiation: neaonates

- Method of breeding: parthenogenesis

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES, INCLUDING CULTURING CONDITIONS: A population of parthenogenetic females of synchronized age structure has been maintained for more than 20 years in the test facilityunder constant temperature conditions (20 +/- 2 °C) at a 16 : 8 hour light : dark photoperiod (light intensity: < 20 µE x m-2 x s-1)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

none

Post exposure observation period:

not applicable

Hardness:

257 mg/L CaCO3

Test temperature:

20.3 to 20.7 °C

pH:

8.6 to 9

Dissolved oxygen:

8.6 to 9 mg/l

Salinity:

not applicable

Conductivity:

no data

Nominal and measured concentrations:

nominal concentrations: 3.13, 6.25, 12.5, 25, 50 and 100 mg/L isoamyl acetate
measured concentration at 48h: 3.04, 5.44, 11.47, 27.75, 50.66, 112.96. Measured test item exposure concentrations ranged from 93.3 % to 108.6 % of their nominal target values at 0 hours and from 87.0 % to 113.0 % of their nominal target values at 48 hours.

Details on test conditions:

TEST SYSTEM
- Test vessel: BOD bottles with glass stoppers with 250 - 300 mL test medium
- Aeration: none
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 6
- No. of vessels per control (replicates): 6

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: 'M4 medium' according to OECD 202 and EC Method C.2
quality measurement: pH, dissolved oxigen and temperature

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

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : alteration of the normal mobility behaviour and the loss of locomotory actions of the neonates, observed at 24 and 48 hours.

RANGE-FINDING STUDY
- Test concentrations: 0.1, 1, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: yes. Effects were in the range between 10 and 100 mg/L. The test item remained stable throughout the test, therefore a static test design was selected.

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

47.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: immobilisation

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

26.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: immobilisation

Details on results:

- Immobilisation of control: below 10%
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: During the tests with Isoamyl acetate a metabolite was formed. Since no analytical standard was available, the determination of the metabolite couldn´t be validated. The concentrations of the metabolite were determined using the test item as calibration.

Results with reference substance (positive control):

not applicable

Reported statistics and error estimates:

The EC 50 was calculated by probit analysis using the statistics programme ToxRatPro Version 2.10 (released 2010-09-10).

Immobilisation of daphnids during exposure period

Nominal test concentration [mg/L]		Immobile daphnia
Replicate		24 hours	Sum [%]	48 hours	Sum [%]
Control	1	0	0	0	0
	2	0		0
	3	0		0
	4	0		0
3.13	1	0	0	0	0
	2	0		0
	3	0		0
	4	0		0
6.25	1	0	0	0	0
	2	0		0
	3	0		0
	4	0		0
12.5	1	0	0	0	0
	2	0		0
	3	0		0
	4	0		0
25	1	0	20	2	35
	2	4		5
	3	0		0
	4	0		0
50	1	3	55	5	100
	2	3		5
	3	2		5
	4	3		5
100	1	4	85	5	100
	2	4		5
	3	5		5
	4	4		5

Probit analysis reasults:

Analysis of the percent immobilised data (by probit analysis) gave the following results (nominal concentrations):

Time    [h]	EC 0 [mg/L]	EC 100 [mg/L]	EC 50 [mg/L]	95 % confidence limits [mg/L]
24	12.5	> 100	47.5	37.7 – 61.4
48	12.5	50	26.3	n.d.
n.d.: not determined due to mathematical reasons or inappropriate data

Analysis Isoamyl acetate (GC)

Nominal concentration [mg/L]	Isoamyl acetate [mg/L]
	0 Hours	24 Hours	48 Hours
Control	--	--	< 2.600 *
3.13	3.016	--	3.038
6.25	5.832	--	5.437
12.5	12.082	--	11.469
25	25.619	--	27.752
50	52.811	--	50.663
100	108.596	104.651	112.963
-- denotes not analyzed; * denotes LOQ

Validity criteria fulfilled:

yes

Conclusions:

Exposure to the test item for 48h to Daphnia magna resulted to an EC50 of 26.3 mg/L.

Executive summary:

A study was conducted exposing the crustacean, Daphnia magna, to the test item for 48 h. The study as performed following the OECD guideline 202 and fulfilled the validation requirements. Measured concentrations confirmed that test item in the exposure concentrations ranged from 93.3 % to 108.6 % of their nominal target values at 0 hours and from 87.0 % to 113.0 % of their nominal target values at 48 hours. Results determined and EC50 for immobilisations of 26.3 mg/L.

Description of key information

A study was conducted exposing the crustacean, Daphnia magna, to the test item for 48 h (Neuhahn, 2019). The study as performed following the OECD guideline 202 and fulfilled the validation requirements. Measured concentrations confirmed that test item in the exposure concentrations ranged from 93.3 % to 108.6 % of their nominal target values at 0 hours and from 87.0 % to 113.0 % of their nominal target values at 48 hours. Results determined and EC50 for immobilisations of 26.3 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

26.3 mg/L

Additional information

Two other supporting studies have been identified:

1) Noack, U. (1990): according to DIN 38412 L 11

EC0 (48 h) = 32 mg/L; EC50 (48 h) = 42 mg/L; EC100 (48 h) = 58 mg/L

2) Bringmann, G., Kühn, R.; Z. Wasser-Abwasser-Forsch., Vol 15/1, 1982, p. 1-6:

exposure duration: 24 h, test organism: Daphnia magna Straus, test according to Prüfvorschrift (engl. transl: test instruction) DIN 38412 Teil 11

Results: EC 0: 114 mg/l; EC 50: 205 mg/l (P 95 % of EC50 (24 h) = 176-242 mg/L); EC 100: 437 mg/l