Isopentyl salicylate

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:

from 2017-02-23 to 2017-11-08

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)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Control, solvent control and all test item concentrations from the main test.
- Sampling method: At the start of the exposure and at renewal (0 and 24 hours), samples of the fresh media were taken after preparation of all test item concentrations and analyzed. At renewal and at the end of the exposure (24 and 48 hours), samples of the 24-hours old media were taken from additional replicates with test media but without daphnids and analyzed.

Vehicle:

yes

Remarks:

Acetone

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: For each test item concentration a separate stock solution was prepared in acetone (solvent) at the start of the exposure renewal intervals (0 and 24 hours). A stock solution of 63 g/L was prepared in a measuring flask (10 mL capacity) by directly weighing of 630 mg test item into the measuring glass flask and followed by filling up with acetone to 10 mL.
- Controls: Control and solvent control
- Chemical name of vehicle: acetone
- Concentration of vehicle in test medium: Acetone was used to achieve the maximum solubility. Preliminary test with the slow stirring method were carried out. This method was not suitable to prepare concentrations near the maximum water solubility. Stirring phases of several days would be necessary and could also produce relevant concentrations of the degradation products. 0.1 mL/L in the stock solution, final test solutions and solvent control
- Evidence of undissolved material: none

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: Clone 5
- Source: Institut für Wasser-, Boden- und Lufthygiene (WaBoLu), 14195 Berlin, Germany; bred at the test facility
- Age of the daphnids at the start of the exposure: Less than 24 hours old
- Feeding during test: no

CULTIVATION
- Culture conditions: n glass vessels (2 - 3 L capacity) with approximately 1.8 L culture medium, at 20 ± 2 °C, in an incubator, 16 hours illumination, light intensity of max. 1500 lx
- Culture medium: Elendt M4, according to OECD 202, Annex 3 (2004), modified to a total
hardness of 160 to 180 mg CaC03/L
- Culture feeding: 5 times per week ad libitum with a mix of unicellular green algae, e.g. Pseudokirchnerielia subcapitata and Desmodesmus subspicatus, with an algae cell density of > 106 cells/mL.
- Acclimation: not necessary

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

169 / 180 mg CaCO3&L

Test temperature:

20.9 ~C

pH:

At test start: 8.8 - 8.9
At test end: 7.9 - 8.3

Dissolved oxygen:

At test start: 8.22 - 9.00 mg/L O2
At test end: 8.51 - 8.91 mg/L O2

Conductivity:

430 - 458 µS/cm

Nominal and measured concentrations:

Nominal test concentrations: control - 0.269 - 0.592 - 1.30 - 2.86 - 6.30 mg/L
Geometric mean measured concentrations: < LOQ - 0.209 - 0.438 - 0.997 - 1.97 - 4.52 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: open
- Material, size, fill volume: Glass beakers (4 (ID) x 7 (H) cm), 50 mL capacity, loosely covered with watch glasses; 20 ml test volume
- Aeration: none
- Renewal rate of test solution: after 24 h
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Culture Medium Elendt M4 according to OECD 202
- Culture medium different from test medium: no
- Intervals of water quality measurement: Prior to the start of the exposure (0 hours) and the renewal of the test solutions (24 hours), the water quality parameters (i.e. pH-value, dissolved oxygen concentration, temperature, conductivity and total hardness) of the dilution water were measured

OTHER TEST CONDITIONS
- Photoperiod: 16/8 hours light/dark cycle
- Light intensity: Diffuse light, light intensity of max. 1500 lx


EFFECT PARAMETERS MEASURED:Biological Parameters: Immobilization was determined in all groups after 24 and 48 hours. An animal was considered immobile, if it was not able to swim in the water phase within 15 seconds after gentle agitation of the test vessel.

VEHICLE CONTROL PERFORMED: yes

RANGE-FINDING STUDY
- Test concentrations: 1, 10 and 100 % of the saturated solution

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

1.97 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

0.997 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

4.52 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: none
- Other biological observations: none
- Mortality of (solvent) control: none
- Abnormal responses: none
- Any observations: none

Results with reference substance (positive control):

EC50 (24 h) = 1.31 mg/L (July 2017)

Immobilization Rates after 24 and 48 hours of Exposure

(n = 20, divided into 4 replicates with 5 daphnids each)

Geometric mean measured concentration of the test item [mg/L]	IMMOBILIZATION [%]
	24 hours					48 hours
	Replicates					Replicates
	1	2	3	4	MV	1	2	3	4	MV
4.52	80	80	80	40	70	100	100	100	100	100
1.97	0	0	0	0	0	60	60	60	60	60
0.997	0	0	0	0	0	0	0	0	0	0
0.438	0	0	0	0	0	0	0	0	0	0
0.209	0	0	0	0	0	0	0	0	0	0
Solvent control	0	0	0	0	0	0	0	0	0	0
Control	0	0	0	0	0	0	0	0	0	0

Calculated Concentrations of the test Item from the Measured Concentration of the Metabolite Isoamyl alcohol and the test item

Values presented asIsoamyl salicylate

Sampling date	2017-07-26 0 hours Start of the exposure interval			2017-07-27 24 hours End of the exposure interval
Start of analysis	2017-07-26			2017-07-27
Nominal test item concentration [mg/L]	Conc. [mg/L]			Conc. [mg/L]
	1)	2)	3)	1)	2)	3)
6.30	4.97	0.0136	4.99	4.55	0.236	4.79
2.86	2.41	0.0205	2.43	1.33	0.120	1.45
1.30	1.19	0.00591	1.19	0.672	0.122	0.794
0.592	0.544	0.00980	0.554	0.252	0.0438	0.295
0.269	0.261	0.00591	0.267	0.138	0.0140	0.152

Sampling date	2017-07-27 24 hours Start of the exposure interval			2017-07-28 48 hours End of the exposure interval			Geometric mean measured Test Item Concentration [mg/L
Start of analysis	2017-07-27			2017-07-28
Nominal test item concentration [mg/L]	Conc. [mg/L]			Conc. [mg/L]
	1)	2)	3)	1)	2)	3)
6.30	6.09	0.0179	6.11	2.72	0.152	2.87	4.52
2.86	2.72	0.0111	2.73	1.47	0.101	1.57	1.97
1.30	1.18	0.00591	1.19	0.828	0.0493	0.878	0.997
0.592	0.549	0.00591	0.554	0.393	0.0147	0.407	0.438
0.269	0.252	0.00591	0.258	0.170	0.0128	0.182	0.209

Conc. = Concentration of the test item (enrichment and dilution factor taken into account)

1)       = Measured concentration of the test item

2)       = Calculated concentration of the test item from measured concentration of the metabolite Isoamyl alcohol calculated with molar ratio to the test item (molar ratio = M(test item) / M(Isoamyl alcohol)

3)       = Summarized concentration of the test item

Validity criteria fulfilled:

yes

Conclusions:

EC50 (48 h) = 1.97 mg/L (based on geometric mean measured concentrations)

Executive summary:

In the acute immobilization test with Daphnia magna, the effects of the test item were determined according to OECD 202 (2004). The study was conducted under semi-static conditions over a period of 48 hours with 5 concentrations of the test item in the nominal range of 0.269 - 0.592 - 1.30 - 2.86 - 6.30 mg/, prepared in a geometric series with a separation factor of 2.2 and corresponding to geometric mean measured concentrations of 0.209 - 0.438 - 0.997- 1.97 - 4 .52 mg/L. All tested concentration levels were visually clear throughout the exposure.

The concentrations of the test item and its degradation product Isoamyl alcohol were analytically verified via GC-MS/MS in fresh media at the start of the exposure and at renewal (0 and 24 hours) and in old media at renewal and at the end of the test (24 and 48 hours) in all concentration levels and the controls.

The validity criteria of the test guidelines were fulfilled.

Based on the geometric mean measured concentrations of the test item, the 48 hour-EC50 for Daphnia magna was 1.97 mg/L.

Description of key information

48 h -EC50 = 1.97 mg/L (geometric mean measured concentrations; Daphnia magna; OECD 202)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

1.97 mg/L

Additional information

One study is available assessing the toxicity of the test item towards aquatic invertebrates. In this acute immobilization test with Daphnia magna, the effects of the test item were determined according to OECD 202 and GLP. The study was conducted under semi-static conditions over a period of 48 hours with 5 concentrations of the test item in the nominal range of 0.269 - 0.592 - 1.30 - 2.86 - 6.30 mg/, prepared in a geometric series with a separation factor of 2.2 and corresponding to geometric mean measured concentrations of 0.209 - 0.438 - 0.997- 1.97 - 4 .52 mg/L. All tested concentration levels were visually clear throughout the exposure.

The concentrations of the test item and its degradation product Isoamyl alcohol were analytically verified via GC-MS/MS in fresh media at the start of the exposure and at renewal (0 and 24 hours) and in old media at renewal and at the end of the test (24 and 48 hours) in all concentration levels and the controls.

The validity criteria of the test guidelines were fulfilled.

Based on the geometric mean measured concentrations of the test item, the 48 hour-EC50 for Daphnia magna was 1.97 mg/L.